MCB 80 master set 1

Define affect

"Feeling or emotion, especially as manifested by facial expression or body language"

How does an action potential alter the membane potential along an axon?

- Na+ enters and causes a LOCAL charge reversal - positive charge displaces negative charges on membrane locally and to a lesser extent in both directions along the axon cylinder - within a few msecs, the Na+ channels inactivate at the site of Na+ entry and that region of the axon membrane becomes refractory to further depolarization - forward direction: positive charges change the membrane potential causing an increase in gNa_ to allow local Na+ entry and allow action potential propagation

What is the structure of the voltage gated Na+ channel

- Single long polypeptide - Four distinct domains, each with six transmembrane alpha-helices (S1-S6). - domains clump, forming a pore - the more is closes at negative resting membrane potential - voltage sensor at S4 (positively charged amino acid residues) - depolarization twists S4 - this conformational change in the molecule causes the gate to open

How is the structure of AChR differ from a VGIC?

- bigger - 2 binding sites - water goes through - less ion specific - 5 proteins in AChR, compared to single long polypeptide chain - M2 domain lines the pore

Microglial Cell

-Come from hematopoietic cells -Macrophage-like Scavenger cells that remove debri from sites of injury or normal cell turnover secrete cytokines that modulate local inflammation and influence if cells live or don't live

Spontaneous Miniature end plate potentials

-Hypothesis was that neurotransmitters are released in packets. due to spontaneous release of a neurotransmitter vesicle. If you want a reliable synapse you want v gated Ca very close to site. High rate of spontaneous mini events in reliable synapses

Neurulation

1) Embryo divides into 3 layers (endoderm, mesoderm, ectoderm) 2) Parts of ectoderm flattens into neural plate, which becomes the neural groove, which pinches off and becomes the neural tube, which becomes the CNS 3) The neural crest becomes the PNS

What are the factors that regulate the effectiveness of synapses?

1) Farther away a synapse is from the initial segment, the less powerful it is 2) Synaptic potentials of different axons sum but in a non-linear way 3) IPSPs interposed between an EPSP and the initial segment block the EPSP from reaching threshold 4) Temporal Summation allows on EPSP to "piggy back" on another 5) Inhibition changes shape of EPSP preventing temporal summation

The Golgi Stain

1) Harden brain with Potassium Dichromate 2)bath in Silver Nitrate -crystals form but remain inside the membrane and one can see neurons Downside: only 1% of cells are stained bc is highly unlikely

2 Major types of acetylcholine (ACh) receptors

1) Nicotinic ACh receptors- ionotropic receptor

What are the axon guidance cues?

1) Permissive 2) Attractive 3) Repulsive

What are the two main components of emotion?

1) Physical expression 2) Conscious percetion

Retinofugal projection

1) Right and left optic nerves go to the optic chiasm (which is where they join) 2) The optic chiasm is the site of decussation: nasal part crosses over to the other side such that left visual field = right hemisphere (and vice versa) 3) After chiasm, the right and left optic tracts contain ipsilateral temporal and contralateral nasal RGC 4) R+L lateral geniculate nucleus (LGN) = relay for RGC 5) R+L optic radiations exit thalamus -> primary visual cortext (aka area 17, V1, striate cortex) of R + L occipital loves of cerebral cortex

Thee Maps in Spinal Cord

1) Segmental map -Relates to the rostrocaudal position of the muscle 2) Mediolateral map -Relates to the proximal (near body axis) to distal (far from body) 3) Flexor -Dorsal to extensor (ventral) map

How are the lower motor neurons organized?

1) Segmental maps that relate to the rostrocaudal position of the muscle in the body (there are more motor neurons in the lumbar region and the cervical region than there are inbetween bc leg and arm muscles) 2) Mediolateral maps where axial muscles are located medially and distal muscles are lateral 3) Flexors are dorsal and extensors are ventral

What are the taste modalities?

1) Sweet (sugar + starch = energy) 2) Salt (Na+ K+ = neurons) 3) Sour (acid = danger) 4) Bitter (bases + toxins = danger) 5) Umami (amino acids + MSG = protein)

Lateral geniculate nucleus

1) Ventral most layers (1,2) have large magnocellular neurons for motion 2) Dorsal layers (3,4,5,6) have smaller parvocellular neurons for shape 3) Between each layer are tiny koniocellular neurons for color

Degeneration + Regeneration in CNS

1) Wallerian degeneration (axon separates from cell body + degenerates) 2) Nerve "stump" or tract persists after axons have degenerated 3) No regeneration :(

Degeneration + Regeneration in peripheral nervous system

1) Wallerian degeneration (axon separates from cell body + degenerates) 2) Nerve "stump" or tract persists after axons have degenerated 3) Peripheral axons regenerate, growing back through the stump and function is often restored

why does concurrent inhibition during temporal summation prevent it?

1) decreases EPSP amplitude 2) reduces membrane resistance --> shortens decay time course of EPSP

what are three ways electricity in the nervous system differs from electricity in wires?

1) ions move around instead of electrons 2) ionic current flows across membranes rather than the way electrons move along wire length 3) no analog to membrane potential in wires

how can quantal size be modulated?

1). changes in postsynaptic receptor density or efficacy (usually) 2) changes in enzymes within the cleft 3) disruptions in packaging neurotransmitter into vesicles (rarely)

Facts about long-term memory

1-8)

how does 4AP change voltage trace?

1. AP amplitude (larger and closer to ENa because decreased permeability of K) 2. Slower rate of decay (during falling phase) 3. no undershoot

GPCR Transmission

1. Binding of the neurotransmitter to the extracellular receptor protein 2. Activation of G-proteins 3. Activation of effector systems

duration of an action potential

2ms

Knockout mutant mice

A) Homologous recombination: generate broken gene that you want to mutate -> integrate the recombinant gene into chromosome in specific place B) Embryonic Stem cells: mutant ES cell can form an entire mutant embryo C) Germ-line chimerism: when you inject ES you get a mosaic -> breed the mosaic and you can get the target knockout mice

two different types of neurotransmitter receptors

A. Ionotropic receptors:ligand-gated ion channels

amyloid plaques are ___ aggregates associated with

AB peptide; Alzheimer's

ACh is cleaved by _______ in the cleft and the choline is taken up by the nerve terminal to be used to make more ACh

ACh esterase

2) Muscarinic ACh receptors-metabotropic; multiple types

ACh is ________ to the heart muscle but is ___________ to the skeletal muscle inhibitory

ACh breakdown

ACh is broken down in the synaptic cleft by acetylcholinesterase into acetate and choline

When channels on muscle fiber open due to binding of

ACh molecules, which ions flow to generate the end-plate potential? the channels are equally permeable to both Na+ and K+. The permeability of the ACh receptors can be determined by evaluating the "reversal potential" evoked by ACh.

ACh receptor

ACh receptor is a type of synaptic receptor at the NMJ located on the muscle. NMJ AcHR are ligand-gated ion channels that desensitize and are activated by nicotine. This channel, when opened, permits the flow of Na+ and K+ currents. There are 2 binding sites per AChR and both need to be occupied for channel to open.

How do principal neurons migrate?

(ones that send axons out of cortex) migrate radially from ventricular zone along radial glia

intrafusal muscle fibers

(sensory/proprioceptors)

Equilibrium potential of Na+

+60 mV

Why are antagonistic (opposite-sign) centers and surrounds useful?

Activation of photoreceptors can lead to ON responses in some cells and OFF responses in others which can be useful in terms of modulation. Useful to be able to detect and respond to something moving that is brighter and something moving that is darker.

Labeled Line hypothesis

Activity of one specific type of neuron by particular taste is both necessary and sufficient to give this taste representation in brain (Taste neurons will have small receptive fields that respond to only bitter, or sweet...etc.)

What evidence suggests that the human nervous system is special?

Adult human nervous system function is unique. Only animal with significant culture (art, music, clothes, religion, architecture)

What is sham rage? and what do experiments that elicit it say about the physical expression of emotion?

After Bard removed both cerebral hemispheres in cats including the anterior hypothalamus animals showed sham rage with even light petting Posterior hypothalamus is necessary - when cull all rage did not occur Hess could instantly elicit rage and attack behavior by stimulation of the hypothalamus

Briefly describe an experiment that tested whether poor central regeneration reflects primarily a defect in the neuron or a defect in the environment - and state his conclusion

Aguayo cut and swapped parts of PNS and CNS and compared regeneration concludes inhospitable environment contributes to the failure of central neurons to regenerate

Axon guidance

At each stage in its journey the growing axon receives directions that guide it to the next destination. The journey is broken into multiple steps. Growth cones sense cues in the environment, react and are, in turn, altered to be ready for next cue.

How do ocular dominance columns form?

At the time the visual cortex is susceptible to sensory deprivation its odcs not fully formed—rather there appears to be considerable overlap between the regions occupied by the thalamocortical axons driven by the two eyes

ACh Antagonists

Atropine or Curare

List 3 classes of skeletal muscles

Axial (trunk) muscles Proximal (girdle) muscles Distal muscles

List the three classes of skeletal muscles

Axial, Proximal, Distal

development?

Axons compete for postsynaptic sites and remaining axon takes over sites vacated by the losers

why do we need oxygen for sodium potassium pump

ATP is generated by glycolysis which is dependent on oxygen. 70% of all energy consumption in brain is used to pump 3 Na+ out, 2 K+ in

What is the flexor reflex?

AVOID NOXIOUS STIMULI WITH EXCITATORY NERVE INNERVATING MUSCLES THAT DRAW AWAY

how attractive and repulsive cues guide axons across the midline

AXONS THAT APPROACH THE MIDLINE ARE INDUCED TO UPREGULATE THE SLIT RECEPTOR ON THEIR MEMBRANES. AXONS EXPRESSING THIS RECEPTOR ARE REPELLED BY SLIT, SO IT PREVENT AXONS THAT CROSS THE MIDLINE FROM BEING ATTRACTED BY NETRIN TO CROSS AGAIN

Define absolute and relative refractory periods

Absolute = no stimulus, no matter how strong, could generate an action potential - Na+ channels completely deactivated Relative = a stronger than normal stimulus is needed in order to elicit an action potential

Induction of Long Term Potentiation

Accumulation of postsynaptic Ca+ -serves as 2nd messenger I Ca2+ entering through postsynaptic NMDA I activation of protein kinesin which regulates traffic in AMPA -enhance postsynaptic response to synapse High intensity stimulating CA3 neurons connecting to CA1 neurons, leads to insertion of additional AMPA receptors

Cerebellum

Balance, Movement, Posture

What do postsynaptic responses look like at chemical synapses

Action potential leads to a depolarizing potential in the postsynaptic neuron if neurotransmitter is excitatory

Glomerulus

Ball like structure in the olfactory bulb where olfactory sensory neurons synapse with the target cells. Each glomerulus receives axons from olfactory sensory neurons that express the same, single olfactory receptor.

Sham rage

Bard removed the cerebral hemispheres & anterior hypothalamus in cats, they still showed anger even w/ light petting When the posterior hypothalamus was removed, rage did not occur

How do cortical neurons encode the depth of an observed object relative to another object that is in focus?

Based on the horizontal disparity in the position of L and R receptive fields of binocular cortical neurons in upper and lower layers. some of these neurons selectively respond to visual objects closer than the plane of focus by being activated by laterally displaced receptive fields. Other cortical neurons respond selectively to farther objects by being activated by medially displaced receptive fields

Axoplasmic transport

Because axons rely on the soma, and protein diffusion way too slow organelles also transported via microtubules motor proteins are tethered to the vesicles and crawl along the microtubules via an ATP dependent mechanism Anterograde - towards synapse, kinesin is the motor protein Retrograde - toward soma, dynein is the motor protein

Why does the distance between a synaptic contact and the initial axon segment matter?

Because the farther an excitatory synapse is from the axon hillock, the less powerful it is even though locally it is the same! because dendrites are leaky cables with resting K permeability (low membrane resistance), are not myelinated (high capacitance), and large axial resistant

Why are the design principles of the brain so much harder to understand than the design principles of a car?

Because we don't know the right level of deconstruction

Why is the motor system so complicated?

Behavior require the coordinated actions of various combinations of 700 muscles in a changing and sometimes unpredictable environment

Why is the motor system so complicated?

Behaviors require the coordinated actions of various combinations of 700 muscles in a changing and sometimes unpredictable environment (stand on one foot: constantly making miniscule changes to not fall over; getting muscles to be exactly in the right place)

How are tics in Tourette's syndrome similar and different from normal eye blinking?

Both blinks and the tics can only be be voluntarily suppressed for a limited amount of time and the inhibition is eventually overridden

How does PET work? What can it measure that fMRI can't and visa versa?

Brain Position Emission Tomography Scan imaging test that captures images of the activity of the brain after radioactive tracers, attached to compounds like glucose, have been absorbed into the bloodstream. Active areas of the brain will be utilizing glucose at a higher rate than inactive areas and PET will highlight this and allow doctors to see how the brain is working/detect abnormalities

What is the method of study in the hippocampus?

Brain slices in vitro - cell bodies of pyramidal neurons -divided into regions -CA1, CA3

Central Nervous System

Brain, Spinal Cord

In what way do neurons and brains resemble each other?

Brain: listen, think, do Neuron: input (dendrites), integrate (soma), gate (axon hillock), output (axon terminals)

Where are brain lesions localized that cause Broca's Aphasia? Wernicke's Aphasia? Conduction Aphasia?

Broca's - Broca's area in frontal lobe Wernicke's - Wernicke's area in temporal lobe Conduction - parietal lobe, arcuate fasciculus

Which aspects of language are disturbed and which spared in Broca's aphasia?Wernicke's Aphasia? Conduction Aphasia?

Broca's - impaired word production, impaired repetition, preserved comprehension Wernicke's - fluent word production, impaired comprehension, impaired repetition Conduction - fluent word production, preserved comprehension, impaired repetition

Olfactory tract

Bundle of axons of mitral and tufted cells that projects to regions of the brain (accessory olfactory nuclei, olfactory tubercle, pyriform cortex and entorhinal cortex.

Autonomic Nervous System

Controls internal milieu continuous, unconscious, involuntary, automatic adjustments indirect -- uses a "relay neuron" -- a pre ganglionic neuron in spinal cord/brainstem sends axon through the ventral root to a ganglion in which it synapses on a ganglion cell that in turn sends an post-ganglionic axon to synapse in an end organ subdivision of PNS sympathetic, parasympathetic, enteric

Define "convergence" and "divergence" as they pertain to synaptic connections and integration

Convergence - one cell influenced by many others (helps cut out the noise, small stimuli) Divergence - one cell influences many others

What does synaptic convergence and divergence mean?

Convergence = many synapsing on one -- summation of multiple axonal inputs converging on the same postsynaptic neuron to bring ideas to threshold Divergence = one synapsing on many -- allows the whole brain to attend to small signals

retinal ganglion cells-->thalamocortical neurons-->

Cortex/V1 thalamocortical terminals

What is meant by cortical lamination? How many layers are there?

Cortical lamination refers to the 6-9 distinct layers in the gray matter, that total in 2mm of thickness. There is a division of function as in LGN but with an entirely different organization.

Mitochondria

Creates energy molecules: ATP

object that is in focus?

Depth perception requires binocular aligned vision and is based on the horizontal disparity in the position of the L and R receptive fields of binocular cortical neurons. Some of these neurons selectively respond to vidsual objects closer than the plane of focus by virtue of being activated by laterally displaced receptive fields. Other cortical neurons respond selectively to objects beyond the plane of focus by virtue of receptive fields that are medially displaced.

lecture?

Developmentally inappropriate social relations

How does activation of photoreceptors lead to on responses in some ganglion cells and off responses in others?

Different bipolar cells have different receptors that react differently to the release of transmitter from photoreceptors. Also FYI Light decreases transmitter release (1) Receptors depolarize the cell when activated by transmitter. So activated in dark and inhibited in light (2) Receptors hyper polarize the cell when activated by transmitter. So activated in light and inhibited in dark

What is chemotropism?

Direction of movement is attractive cues that cause axons to grow in a particular direction. Demonstrated in peripheral system (NGF)

5 Factors Affecting Synaptic Effectiveness

Distance decreases Signal Strength Non-Linear Summation Inhibition (increase gCl-) between Excitation and Soma blocks depolarization Temporal Summation( which is itself is prevented by shunting)

What types of axons run in the dorsal and ventral roots?

Dorsal Roots - Sensory Axons Ventral Roots - Motor Axons

Why does the shape of an EPSP have a fast rise and a slow fall?

During the rise the LGICs are open so membrane resistance is low and charge passes through membrane quickly During the fall the LGICs are mostly closed so membrane resistance is higher and it takes a longer time to remove the added positive charges, hence the falling phase is slower than the rising phase

Differentiation

Dynamic polarizations (axons and dendrites) + choice of neurotransmitter

Endplate potential

EPSP at neuromuscular junction. Differs from normal EPSP in that it doesn't require integration with other inputs to initiate an action potential in the muscle fiber--important the you reliably get a response in muscle

How to activate a LTP

EPSP in postsynaptic CA1 cell, there must be brief high-frequency stimuli mechanism for lasting memory storage of info

Temporal summation

EPSP's in postsynaptic cell-postsynaptic cell reaches threshold and action potential is generated

Define temporal summation. How is it related to the shape of synaptic potentials?

EPSPs "piggy-backing" on each other. When a presynaptic terminal is activated at high frequency the postsynaptic amplitude sums because each EPSP sits on the slow falling phase of the previous potential

Unlike action potentials,

EPSPs and IPSPs are not propagated. postsynaptic potentials have to flow electronically toward the axon hillock (spread through conductive cytoplasm

Facilitating synapses

EPSPs get larger with repeated action potentials from the presynaptic neuron

Depressing synapses

EPSPs get smaller with repeated action potentials from the presynaptic neuron

synaptic attenuation

EPSPs in dendrites obey cable properties and their amplitudes will decrease along the length of the dendrite

Metabotropic receptors can amplify the effects of neurotransmitter binding

Each activated receptor can activate many G-proteins and Each activated cyclase can catalyze the production of many second messenger molecules (e.g., cAMP) These second messenger molecules can activate kinases (as in the cAMP example)

What key piece of evidence proved that most synapses use chemical rather than electrical transmission?

Electron microscopy: showed that pre- and postsynaptic membranes aren't in direct contact at most synapses (neurons are separated by about 20-30nm (synaptic cleft), which couldn't be distinguished by light microscopy)

Radial glial cell

Elongated cells that form tracks; these provide guidance for cells in ventricular zone to ride on up and get where they are supposed to beDuring development, newborn neurons use radial glia as scaffolds, traveling along the radial glial fibers in order to reach their final destinations. These dividing cells—the neural progenitors that give rise to all the neurons and astrocytes of the cerebral cortex—are called radial glial cells. For many years it was believed these cells served only as a temporary scaffold to guide newly formed neurons to their final destinations. We now understand that the radial glial cells also give rise to most of the neurons of the central nervous system.

Thalamus

Emotion, Information processing

Are human facial expressions cultural or intrinsic - what is the evidence?

Emotional expression in humans is more about face than body language Darwin made the point that these expressions are found thoughout all of humankind- suggesting intrinsic not cultural mechanisms

to remember than the answers to these quiz questions?

Emotional value of memories important part of the coding

What are the 3 primary cell layers of the early embryo and from which does the nervous system arise?

Endoderm, Mesoderm, Ectoderm Ectoderm - gives rise to nervous system and skin Mesoderm - muscles and bones Endoderm - gastrointestinal tract, organs

nervous system arise?

Endoderm: gives rise to gastrointesitinal tract, organs (liver, pancreas...)

shunting inhibition

Even though the reversal potential (E_CI) for inhibitory synapses is approx the resting membrane potential, the opening of GABA channels is veyr effective inn preventinng the postsynaptic neuron from reaching threshold. This inhibition essentially allows CI- entry anytime the membrane potential is depolarized. This shunts the excitatory synaptic current

Miniature excitatory post synaptic potential (mPSP):

Exactly the same as miniature end plate potential but applies to neuron-neuron connections.

Where are inhibitory synapses vs. excitatory synapses located on a neuron?

Excitation -- dendritic spines Inhibition -- dendritic shafts, soma, and axon hillock

How and where in the cell are neuropeptides synthesized?

Exclusively produced in the cell soma without local synthesis in nerve endings They are then processed in the endoplasmatic reticulum and then move to the Golgi apparatus to be processed further. They leave the Golgi apparatus within secretory granules and are transferred to terminals by fast axonal transport Neuropeptides act through GPCRs

What does the prefrontal cortex do?

Executive functions (e.g.. personality, decision making, moderating social behavior) found out through Phineas Gage and his injury/ bar through his prefrontal cortex

List 3 criteria for classifying a disorder as PTSD?

Exposure to trauma Recurrent distressing intrusive symptioms (e.g. flashbacks) Avoidance of stimuli associated with trauma Increased arousal (e.g. hypervigilance)

Why might a taxi driver have an abnormally large part of the hippocampus?

Extensive spatial memory experiences causes hypertrophy of part of the hippocampus and atrophy of another part with functional consequences

G Protein Coupled Receptor (GPCR)

Extracellular domain binds transmitter, hormone, and other molecule (Different binding preferences!) Intracellular domain binds a set of 3 proteins called G Proteins Binding of ligand outside affects G Proteins inside, activates/inactivates them often the activated G Proteins are enzymes and generate second messengers

Facilitation vs. Depression

Facilitation tends to be seen in unreliable synapses, synapses in which release probability was low for the first stimulus.. Depression tends to be seen in reliable synapses, synapses in which release probability was high for the first stimulus

A neurologist tests the stretch reflex on both knees of a patient and finds: Both reflexes are abnormally strong (hyper-reflexic). Name a problem that could lead to this symptom.

Failure of inhibition, usually from the brain (upper motor neuron)

Reactive Attachment Disorder

Failure to initiate or respond to social interactions Or Indiscriminate sociability, excessive familiarity with strangers

True or False: Each gustatory sensory neuron responds to multiple different types of tastes

False

T or F: tapping the patellar tendon harder causes a larger muscle contraction because there is a larger action potential in the 1a afferent.

False (higher FREQUENCY of action potential)

T or F: spines are presynaptic sites

False (postsynaptic)

List 3 different ways to functionally classify synapses

Fast (ligand gated) vs Slow (second messengers) Excitatory (depolarize post synaptic) vs Inhibitory (hyper polarize post synaptic) Strong vs Weak (require integration)

ways to classify synapses

Fast/slow, excitatory/inhibitory, strong/weak

Fast and slow receptor

Fast: Ionotropic Slow: metabotropic

what are two advantages of electrical synapses compared to chemical ones?

Faster: often in places where a fast response is required Tamper-proof energy efficient very synchronous

Sympathetic ANS

Fight of Flight Adrenergic system Neurotransmitter = Norepinephrine

How does taste work?

Food is dissolved -> chemicals contact microvilli -> cell depolarizes

Briefly describe how sour taste is sensed

Foods taste sour because of high acidity. Acids such as HCl dissolve in water and generate protons H+. For sour taste, the entry of protons into the taste cell, deactivates the potassium ion channel which then depolarizes the cell. In BOOK, it is likely that H+ can bind to and block special K+-selective channels. When the K+ permeability is decreased, it depolarizes.

Specificity in synapse formation

Forming synapses on the right part of the right target cell (lock and key)

Bitter tastes in sweet cells

Found that it is the cell, not the receptor, that leads to behavior

Name the 4 lobes of the cerebral cortex and describe their locations?

Frontal Lobe (front of brain, top, distant from brainstem/cerebellum) Parietal Lobe (behind frontal lobe, top of brain) Occipital Lobe (below and behind parietal lobe, on top of back part of cerebellum/brainstem) Temporal Lobe (below frontal and parietal lobe, in front of occipital lobe, on top of front part of cerebellum/brainstem)

How does the fMRI work and what is the BOLD signal?

Functional magnetic resonance imaging (fMRI) basically measures brain activity by detecting changes associated with blood flow. The BOLD signal measures oxymoglobin in the brain -- e.g. high oxyhemoglobin seen when brain is active. this allowed us to remake the Brodmann map of the functions and part of the brain, alongside other important uses

Magnocellular

Functional stream leaving/entering LGN. Neurons associated with Motion.

Parvocellular

Functional stream leaving/entering LGN. Neurons associated with Shape.

What are the main contributions of George Wald and Steven Kuffler to our understanding of how the retina words?

G Wald - Phototransduction pathway with Rhodopsin S Kuffler -recorded responses of retinal ganglion cells, identified receptive field

Olfactory sensory neurons are activated via what mechanism?

G-Protein Coupled Receptors

major inhibitory neurotransmitter in brain

GABA

which channel's reversal potential is -65mV

GABA

Name the main inhibitory neurotransmitters and where they are found in the nervous system. What ionic conductance do they affect?

GABA and Glycine GABA and Glycine Receptors -- Cl- (increases gCl-)

inhibitory neurotransmitters we talked about

GABA and glycine

GABA "A"

GABA receptor on postsynaptic cell. The channel pore is lined with positively charged amino acids. GABA causes this ligand-gated receptor to open allowing gCI- to increase, therefore LGIC is anionic.

How do benzodiazopenes work and why might they decrease anxiety?

GABA receptor potentiators that increase inhibition and make the GABA receptor more openable

receptors used to treat anxiety disorders

GABA receptor potentiators: Cl- channels--hyperpolarized. benzodiazepine is a potentiator

GABA receptor

GABA-gated ion channel. Similar to nAChR but permeable to CI- instead of cations. Reversal potential of GABA receptor is therefore equal to E_CI

GABA receptor

GABA-gated ion channel. Similar to nAChR but permeable to Cl- instead of cations. Reversal potential of GABA receptor is therefore equal to ECl.

What is GFP and how might it be useful in the study of synaptic circuits?

GFP - green fluorescent protein allows us to label each cell using a technicolor golgi stain using fluorescence

endoderm tract

GI tract

Describe a mechanism that allows 2 different neurotransmitters to affect the same channel in opposite ways

GPCR signaling can lead to multiple effects EG in the autonomic system it allows norepinephrine and AChR to exert opposite effects on the same process

Fat

GPR40 + 120 respond to fatty acids

chemotropism

GROWTH TOWARDS A PARTICULAR CHEMICAL

Amino Acids

Glutamate;Excitatory; Glutamine GABA;Inhibitory; Glutamate Glycine;Inhibitory;Serine

Describe Camillo Golgi's most important contribution to neuroscience

Golgi discovered the Golgi Stain, which, through the "black reaction," revealed neurons in their entirety. Golgi also proposed the "Reticular Theory" - nervous system net like, diffuse structure with no cellular entities - which was wrong!!

Graded potential VS. Action potential

Graded: at dendrites and cell body, excitatory/inhibitory, smaller, triggered by input from outside, many happen at once, different sizes Action: at axon, always excitatory, larger voltage difference, triggered by membrane depolarization, one at a time, All-or-none.

How, in general, are recognition molecules deployed in the tectum and retina?

Gradients (Eg EphrinA gradient high in posterior and low in anterior tectum)

How are recognition molecules deployed in the tectum and retina?

Gradients seen in retina and tectum Many gradients of different molecules (too many!)

How does the structure and function of synapses change as development proceeds?

Gradual construction both presynaptic and postsynaptic sides change refines over development

How do large-scale changes happen?

Growth or loss of axon branches; formation or elimination of synapses; formation of new neurons

Name 3 chemical senses

Gustation, Olfaction, Visceral chemosensation, CO2 and O2 detection, and Pheremone reception

Gustatory cortex? Olfactory cortex?

Gustatory - in the top of the temporal lobe, Receives impulses when the taste buds are stimulated Olfactory - in the top of the temporal lobe, Receives impulses when the olfactory receptors of the nose are stimulated.

consolidate declarative memory

HM could not

Who is HM and what was wrong with him?

HM had a bike crash that led to him having seizures. Tried to treat seizures surgically and removed parts of the brain. Following surgery he could not consolidate declarative memory and spatial orientation severely affected

Nasal retina

Half of the retina closest to the nose, receives visual information from the ipsilateral visual field and fibers project to the contralateral LGN

Temporal retina

Half of the retina closest to the temple, receives visual information from the contralateral visual field and fibers project to the ipsilateral LGN

Increased motivation/attention

If you actually made the remapping matter (owls had to hunt for their own food), they remapped better

How we perceive something (pleasing, displeasing) is a property of what neurons the electrical impulses are.. ie

If you put rhodopsin into a taste bud, can have mice avoiding or either attracted to light on the taste bud

List the 3 temporal categories of memory and define each

Immediate - sense of the present Short term - seconds to minutes. working memory Long term - days to decades

List the three temporal categories of memory and define each.

Immediate memory: our sense of the present

What does the internal representation of a movement specify? What doesn't it specify?

Important law of internal representation: Brain represents the outcome of motor actions in a way that is independent of the specific muscles used or way the goal is achieved

horizontal cells

In a lateral pathway, signals are sent through _____ cells first before being sent through interneurons to RGCs. _____ cells make synapses between photoreceptors.

Gap junction

In electrical synapses -- allow current to flow between pre and postsynaptic cells (the ions flow through gap junction channels)

How exactly does Ca2+ cause release of transmitter?

In its dephosphorylated state, synapsin ( ) has a high affinity for both actin and the vesicle membrane

NMDA receptor

In low-frequency synaptic transmission -glutamate binds to NMDA I but Mg 2+ block prevents current flow I EPSP are entirely mediated by AMPA receptors

Reversal potential for IPSP

In the case of fast synaptic inhibition (such as the interneurons innervating the motoneurons of antagonistic muscles in the stretch reflex), the reversal potential for the IPSP is equivalent to the equilibrium potential for Cl- (about -80 mV for this synapse) because binding of the inhibitory neurotransmitter glycine causes Cl- channels to open. For synapses expressing GABA-A receptors, the IPSP reversal potential is also equivalent to the equilibrium potential for Cl-

Midbrain

Information relay to forebrain, wakefulness, drowsiness, involuntary movements

In the context of synaptic potentials, what is inhibition?

Inhibition - make cell more electronegative, farther from threshold so that action potentials cant fire eg. in knee jerk reflex need to inhibit the antagonistic muscles (reciprocal inhibition)

How and why does inhibition affect temporal summation?

Inhibition changes the shape of EPSPs and prevents temporal summation -- concurrent inhibition decreases the membrane resistance allowing the falling phase to return to the resting potential quickly (via Cl- entry)

With reference to feeding - How does the brain sense fuel levels over the short term? What does it want to know?

Input = Carb levels and dissension of stomach Hunger signal = Ghrelin Satiety Signal = Insulin and Stretch receptors

What is the relationship of birth order to laminar position for cortical neurons?

Inside out birth order and laminar position

What is the relationship of birth order to laminar position for cortical neurons?

Inside-out birth order and laminar position

SNARE "hypothesis"

Interactions between SNARE proteins on the vesicle and on the presynaptic membrane, modulated by calcium, lead to vesicle fusion.

How might Hebb's postulate explain ocular dominance segregation and the effect of eye patching?

Interaxonal Competition (binocular rivalry) activity based -- alternating eye patching experiment in development wipes out binocular neurons in cortex in later life and protects the vision

Gap Junctions

Intercellular cytoplasmic continuities between some neurons -direct transfer of electrical/chemical signals between cells in NS

Bipolar cells

Interneurons Between photoreceptors and retinal ganglion cells. Used for processing. In a Direct pathway, _____ cells send signals from photoreceptors to retinal ganglion cells.

Why don't mice like Diet Coke?

Interspecies differences - humans past aspartame (nutrisweet) but mice don't.

What is the difference between intrafusal and extrafusal muscle fibers?

Intrafusal - skeletal muscle fibers that serve as specialized sensory organs (proprioceptors) that detect the amount and rate of change in length of a muscle. They are innervated by two axons, one sensory and one motor Extrafusal - skeletal standard muscle fibers. Innervated by alpha motor neurons. They generate tension by contracting, and thereby allow for skeletal movement. They make up large mass of striated muscle and are attached to bone by tendons

ionotropic receptors

Ion channels that open when neurotransmitter binds. Receptor site and channel are part of the same molecule. are fast and act to rapidly depolarize

Tastes and respective channels

Ionotropic: -Salty (NaCl) -Sour (H+) GCPRs: -Sweet -Umami -Bitter

There is also a coupled transporter, which exchanges internal Ca2+ for external Na+

It becomes active when the internal [Ca2+] rises

What is the value of electron microscopy in studying synaptic circuits?

It has suitable resolution to see every axon, dendrite, and synapse. Much better resolution than light microscopy

Alzheimer's disease

It is a form of progressive dementia and one in which the memory is affected early (people first lose ability to acquire new memory). Slowly robs people of their most human qualities—memory, insight, judgment, abstraction, language. Characteristic brain changes

What is retinopy? What part of the visual map is magnified?

It is the 2D surface of the retina (topographically arranged) mapped onto the 2D surface of the subsequent structures (thalamus and cortex) the central few degrees of visual field are overrepresented/magnified for better acuity in the center of the visual field

What is a growth cone?

It is the tip of the growing axon and has a very specialized structure that is specialized for growth and navigation. It displays seeking behavior.

emotion?

John Downer (1950s) removed one amygdala in monkeys and transected the optic chiasm and the commissures (corpus callosum) that link the two hemispheres: in so doing he had an animal with a single amygdala that had access to visual information only from the eye on the same side of the head

glia cells are only permeable to the ion ____

K+

Ion flow situation:

K+ concentration gradient flowing it out, electrical gradient making it flow in. Na+ electrical and concentration gradient pushing it out. K+ is more permeable.

What is a delayed rectifier channel and how does it participate in the action potential?

K+ conductance is the delayed rectifier In an Action Potential -- (1) depolarization (2) Na+ entering the cell (3) peak (4) fall in Na+ (5) K+ leaving the cell (7) Bottoms out (8) Slight fall of K+

Critical period for audio-visual remapping

Knudsen found that if he put prism goggles on owls that shifted their vision by X degrees; eventually with experience they were able to rewire their audio-visual mapping to compensate for this shift

glycoprotein in the matrix permits axons to grow

LAMININ

in vitro stripe assay

LEADS TO THE IDENTIFICATION OF A LARGE NUMBER OF RECOGNITION MOLECULES IN THE RETINOTECTAL PATHWAY

Why do native Japanese speaker say /r/ and /l/ similarly, while native English speakers say them differently?

Language Specific Phonemic Distinctions - you lose the ones you don't hear used - americans cant understand the fuzziness of the unknown sounds made by the Japanese so we cant comprehend the sound/ miscategorize it

Describe center surround organization of retinal ganglion cells

Lateral pathway (horizontal and amacrine cells) generate center surround organization through the lateral inhibitory connections provided by the horizontal and amacrine cells Direct pathway (bipolar cells send signals from photoreceptors to retinal ganglion cells) constructs on/off centers

How well does the presynaptic neuron buffer left-over Ca2+? (calmodulin, parvalbumin, ATP)

Left-over Ca2+ in the presynaptic terminal can affect the presynaptic neuron's future release properties

Describe the structure of an AChR. How does it differ from a voltage gated ion channel?

Ligand gated ion channel - ACh (the ligand) causes conformational change in the ACh (the receptor) 5 subunits, each with 4 membrane spanning domains --m1 through m4 2 ACh binding sites VS V-gated ion channels ... Bigger Ion plus water entourage goes through Less ion specific

from photoreceptors?

Light depletes cyclic GMP, closing the channel and hyperpolarizing the cell

What is depression?

Most common of the major psychiatric disorders

Nucleus

Most protein synthesis occurs

Synaptic rearrangement

Most rearrangements are activity-dependent, and a main way that experience shapes the nervous system The nervous system is particularly susceptible to experience-dependent remodeling during early postnatal "critical periods"

efferent neurons

Motor - control skeletal muscle. Autonomic - control smooth muscle. CNS information to PNS

With reference to thermoregulation - what are the 3 components of the response?

Motor - modulatory signals to brain (motor patterns) -- shiver or pant Autonomic - constrict blood vessels to save heat or stimulate sweating to disperse heat Endocrine -release of thyroxin by the thyroid which affects metabolic rate and efficiency ... releases thyroid releasing hormone TRH to command release of thyroid stimulating hormone TSH from pituitary, leading to release of thyroxin by the thyroid which affects metabolic rate and efficiency

dorsal root v. ventral root

Motor axons leave the spinal cord through ventral roots. Sensory axons enter the spinal cord through dorsal roots. Sensory axons bundle to form dorsal roots and motor axons bundle to form ventral roots.

"Henneman's Size Principle"?

Motor neurons generate muscle force by sequential recruitment to fire action potentials- begin with the smallest/weakest and end with the largest/strongest needed to accomplish motor action

Rapidly adapting fibers are most likely to provide information about the _______ of a stimulus.

Movement

ACh Agonists

Muscarine or Nicotine

relationship between MEPP and EPP

Muscle contraction must be prevented so that microelectrode isn't dislodged. This can be done by lowering Ca2+ concentration or partially blocking the postsynaptic ACh receptors. Lowering Ca2+ concentration reduces neurotransmitter secretion, which reduces magnitude of EPP below the threshold for postsynaptic action potential production. Under such conditions, stimulation of motor neurons produce very small EPPs that fluctuate in amplitude from trial to trial. EPPs are simultaneous release of many MEPP-like units.

How do amacrine cells make retinal ganglion cells sensitive to edges?

The center- surround organization provided for by amacrine cells makes ganglion cells very sensitive to contrast and edges - well aimed light

How do amacrine cells make retinal ganglion cells sensitive to edges

The center-surround organization of receptive fields of ganglion cells and bipolar cells is created by the lateral inhibitory connections provided by the horizontal and amacrine cells. Lateral inhibition is not peculiar to the visual system. It is present in other sensory systems as well, as you may recall from the section on the somatosensory system. The features to which a retinal ganglion cell responds best (edges, shadows, moving objects, colors) depend on which amacrine and bipolar cells synapse on it

Why is the summation of voltage non-linear?

The closer the membrane potential gets to reversal potential, the lower the net driving force. A synapse can't depolarize the membrane beyond the reversal potential, so adding many synapses together can only approach -10mV and each additional input has less effect

What are ocular dominance columns? How are they revealed?

The columns span multiple cortical layers, and are laid out in a striped pattern across the surface of the striate cortex (V1) In Layer 4 of these columns the input is segregated - left eye vs right eye Radioactive LGN terminals labeled by transsynaptic transport of radio- active proline containing protein injected into only one retina (white stripes)

What causes release of neurotransmitter from vesicles?

The depolarization brought to the axon terminal by the action potential leads to the opening of voltage-gated Ca2+ channels Increases in the intracellular concentration of Ca2+ lead to neurotransmitter release The key event is Ca influx. Ca needed inside pre-synaptic terminal, the Action potential depolarizes pre-synaptic terminal

How does the effect of monocular deprivation vary with the age of the deprivation?

The earlier the eye is deprived the more profound the loss of cortical area occupied by the deprived eye - the territory held by the deprived eye is the territory it had exclusive control over at the time of development after critical period, deprivation had no effect

deprivation?

The earlier the eye is deprived the more profound the loss of cortical area occupied by the deprived eye. The territory held by the deprived eye is the territory it had exclusive control over at the time of deprivation

Apoptosis

The expression of cell death genes causes neurons to die by a process called apoptosis, the systematic disassembly of the neuron. Apoptosis differs from necrosis, which is the accidental cell death resulting from injury to cells.

Glycine receptor

The glycine receptor is similar to the GABA-A receptor (~40% similarity). It is also an ion channel that is permeable to Cl- ions

Growth cone

The growing tip of a neurite... it is specialized to identify an appropriate path for neurite elongation.

to the ocular dominance histogram?

The histogram is shifted in later life in favor of the un-patched eye. Vision from the deprived ye is amblyopic

Is the lack of regeneration in the CNS (when compared to PNS) due to the neuron or the environment?

The inhospitable environment is what contributes to the failure of central neurons to regenerate.. 1) not have enough trophic factors 2) components of myelin inhibit axon growth 3) astrocytes @ site of injury deposit scar tissue 4) Neuron might also have problems that decrease ability to reenter "growth state

Parkinson's:

The initiation of willed movements is inhibited because of more tonic (continuous) inhibition of the thalamic input to Premotor cortex. hypokinetic; very decreased muscle movements; shortened stride length. Movements are very, very small

What is M1? What does it innervate? How is it different from other motor areas in

The lowest energy stimulation that he needed to get the body to move was found in the area of the brain called the M1 contralaterally only if the stimulation (primary motor cortex) was localized just anterior to the central sulcus in an area now known as M1. Area 6 ("premotor" cortex) stimulation elicits movements but these are more complex. The posterior parietal area is essential or the planning of purposive movements. When we make a movement in a particular direction a subset of M1 neurons fire.

Reversal potential

The membrane potential(Vm) at which the current reverses from inward to outward (or outward to inward) determined by voltage clamping the membrane to various membrane potentials while stimulating the motoneuron and causing it to release ACh.

What makes a ligand gated ion channel selective for cations?

The pores are lined with negative amino acids

A normal EPSP (or EPP) is a response to release of many, many of these quanta but

a Miniature EPSPs (and miniature EPPs) are the result of spontaneous release of a single quantum of neurotransmitter Chances are very low that two release sites would do this at the same time

Why is a cell membrane like a capacitor?

a capacitor stores energy in the form of an electrostatic field between its plates likewise in a cell opposite charges attract and line up on either side of the membrane which stores charge

Short-term plasticity

a change in synaptic strength (timescale of milliseconds to seconds) caused by presynaptic mechanisms which alter the quantal content (average # of vesicles released by one presynaptic action potential ).

Morphogen

a chemical morphogen released from one end of the axis forms a gradient, and the concentration of morphogen determines which genes are activated/expressed involved in regionalization

Morphogens

a chemical released from one end that forms a gradient and the concentration of the chemical determines which genes are activated

morphogen

a chemical substance released by organizer cells that moves form one tissue to the target tissue, helping with induction in a developing embryo.

Central Pattern Generators (CPGs)

a circuit that is capable of producing rhythmic output for coordinated contraction of different muscles without sensory feedback

Motor pool

a cluster of motor neurons that innervate the same muscle.

Electrical Synapse

a connection between two cells though gap junctions that allows the direct passage of electrical current (ions). Allows for the fast and often bidirectional transfer of electrical information between cells.

Habituation

a decrease in the magnitude of behavioral responses to repeated stimuli. In Aplysia, repeated stimulation of the siphon causes a reduced gill retraction after multiple stimulations.

What is multiple sclerosis?

a demyelinating disease

define multiple sclerosis, including biologic and physiologic symptoms

a demyelinating disease, paralysis, muscle fatigue

Electrical Potential Difference (V)

a difference in potential energy that exists when there is a separation of charges (electrical gradient). Measured in volts (V) and typical potentials in neurons are measured in millivolts (mV).

Opsins

a family of g-protein couple receptors found in the membraneous disks of photoreceptors. In rods opsin is coupled with retinal (a molecule derived from vitamin A) to form rhodopsin. Retinal can have 2 different isoforms. (11-cis and all-trans retinal)

What is the relationship of FoxP2 to language?

a gene mutated in some specific language impairments that are heritable/run in families its a transcription factor that regulates the expression of other genes

Receptor potential

a graded potential in the dendrites of a sensory neuron in response to a stimulus. A larger stimulus will create a larger potential. If the threshold to fire an action potential is met, an action potential will be initiated in the sensory neuron.

SNARE complex

a group of proteins that cause vesicle fusion and release of neurotransmitter in response to an elevation in Ca2+ levels in the presynaptic terminal. Consists of proteins on both the visible membrane and the presynaptic terminal cell membrane.

synapse

a junction, typically between the axon of one cell and dendrite of another, that permits signals to transfer from a neuron to another cell

Synapse

a junction, typically between the axon of one cell and dendrite of another, that permits signals to transfer from a neuron to another cell.

Sodium Potassium Pump

a membrane protein that uses metabolic energy (ATP) to transport ions across the membrane against their concentration gradients. Specifically it pumps 3 Na+ from inside to outside, then pumps 2 K+ into the cell. It is responsible for the fact that Na+ has a higher concentration outside the cell and K+ has a higher concentration inside the cell. Selective permeability (especially of K+ "leak" channels) combined with the concentration gradients established by the pump, create the negative resting membrane potential.

What is a motor unit?

a motor neuron and all of the muscle fibers it innervates

motor unit

a motor neuron and all of the muscle fibers it innervates (example of divergence)

Synapse formation

a multi-step process involving acquisition of many pre- and postsynaptic features and their perfect apposition.

What is multiple sclerosis?

a neurological disorder which attacks the myelin sheaths. People with MS are characterized by a marked slowing of the conduction velocity of their optic nerve

excitatory neuronn

a neuron, that when active and fire action potentials, increases the probability that the neuron it connects to via synapses will also fire an action potential

Excitatory neuron

a neuron, that when active and fires action potentials, increases the probability that the neurons it connects to via synapses will also fire an action potential.

Inhibitory (often an interneuron)

a neuron, when active, that is fires action potentials, decreases the probability that the neurons it connects to via synapses will fire an action potential. Many inhibitory neurons do not send their axons very far, making local connections and are referred to as interneurons.

inhibitory neuron

a neuron, when active, that when fires action potential, decreases the probability that the neuron it connects to via synapses will fire an action potential

neurite

a neuronal process or projection that arises from the cell body, either an axon or a dendrite

Neurite

a neuronal process or projection that arises from the cell body, either an axon or a dendrite.

With reference to feeding - What is leptin and what ware the main components of the response to (too much of) it?

a neuropeptide made and released by fat cells. It travels to the hypothalamus to activate its receptors. Leptina and fat production are proportional -- more fat, more leptin Response -- Motor: activate lateral hypothalamus neurons, inhibit feeding centers Autonomic: activate sympathetic neurons, increase metabolism Endocrine: stimulate release of pituitary hormones, increase metabolism

With reference to feeding - What is ghrelin and how might it be harnessed to treat obesity?

a neuropeptide released from the stomach when its empty that acts on the hypothalamus its a hunger signal decrease gherkin, decrease hunger, treat obesity

Metabotropic receptor

a neurotransmitter receptor that effects neuron excitability or membrane potential indirectly through intracellular signaling cascades.

Drive (aka motivated behavior)

a physiological state that prompts activity toward a particular end. subconscious Characterized by tension and discomfort due to physiological need, followed by relief when the need is satisfied

Presenilin 1 (PS-1)

a presenilin protein that in humans is encoded by the PSEN1 gene. Presenilin-1 is one of the four core proteins in the gamma secretase complex, which is considered to play an important role in generation of amyloid beta (Aβ) from amyloid precursor protein (APP). The presenilin 1 and presenilin 2 genes have been identified as pathogenic loci involved in the majority of early onset, autosomal dominant Alzheimer's disease. A series of missense mutations have been identified in the two genes which lead to disease.

axodendritic synapse

a presynaptic axon that establishes a synapses onto a dendrite or spine of the postsynaptic cell. Synapses onto spines and distal axodendritic synapses are typically excitatory

Axodendritic synapse

a presynaptic axon that establishes a synapses onto a dendrite or spine of the postsynaptic cell. Synapses onto spines and distal axodendritic synapses are typically excitatory.

Axosomatic synapse

a presynaptic axon that establishes a synapses onto the soma (cell body) of the postsynaptic cell. Axosomatic synapses are often inhibitory.

axosomatic synapse

a presynaptic axon that establishes a synapses onto the soma of the postsynaptic cell. Often inhibitory

Wallerian degeneration

a process that results when a nerve fiber is cut or crushed, in which the part of the axon separated from the neuron's cell body degenerates distal to the injury. This is also known as anterograde or orthograde degeneration

Tau

a protein normally associated with microtubules that aggregates in Alzheimers to form Tangles

Each vesicle contains

a quantum of neurotransmitter

What is a reflex?

a reaction to a stimulus that is automatic, unlearned, involuntary & unconscious

Glial (astrocytic) scar

a reactive cellular process involving astrogliosis that occurs after injury to the Central Nervous System. As with scarring in other organs and tissues, the glial scar is the body's mechanism to protect and begin the healing process in the nervous system.

NMDA receptor plays

a really important role in learning and memory

EphA

a receptor tyrosine kinase- that is high in posterior and low in anterior

What is a reflex? give two exampeles

a reflex is an unconscious, involuntary, and innate response to a stiumulsu. The myotatic stretch reflex and gag reflex are two examples

Burning stovetop and flexion

a sensory impulse that travels to the central nervous system, synapsing with interneurons that connect to motor neurons. Some of these send motor impulses to the flexors that lead to the muscles in the arm to contract, while some motor neurons send inhibitory impulses to the extensors so flexion is not inhibited.

excitatory postsynaptic potential (EPSP)

a slight depolarization of a postsynaptic cell, bringing the membrane potential of that cell closer to the threshold for an action potential. Results from the activation of an excitatory chemical synapse.

The net movement of ions across a membrane may alter both the membrane potential as well as the relative concentrations of the ion on each side of the membrane. Compare these effects.

a small number of ion movements can change membrane potential dramatically So concentration gradients are not significantly disturbed in achieving equilibrium

dendritic spines

a small protrusion on a dendrite of some neurons (especially excitatory cells) that receives a synaptic connection from axon terminals and compartmentalized the chemical and electrical signals

Dendritic spines

a small protrusion on a dendrite of some neurons (especially excitatory cells) that receives a synaptic connection from axon terminals and compartmentalizes the chemical and electrical signals.

Golgi stain

a sparse stain that labels a relatively small number of neurons; Cajal used it to understand the connections between neurons and the directional flow of information

Morphogen

a substance whose non-uniform distribution governs the pattern of tissue development in the process of morphogenesis or pattern formation, one of the core processes of developmental biology, establishing positions of the various specialized cell types within a tissue. More specifically, a morphogen is a signaling molecule that acts directly on cells to produce specific cellular responses depending on its local concentration. Is a substance governing the pattern of tissue development in the process

Long term depression

a sustained weakening of synaptic connections caused by previous patterns of neuronal and synaptic activity. Several different mechanisms have been found underlying LTD at different synapses. In the hippocampus, small, spaced activation and opening of NMDA channels leads to a signaling cascade which also eventually causes the internalization of AMPA receptors.

Inhibitory synapse

a synapse where the release of neurotransmitter decreases the likelihood that the postsynaptic neuron fires an action potential.

Excitatory synapse

a synapse where the release of neurotransmitter increases the likelihood that the postsynaptic neuron fires an action potential.

suprathreshold potential

a synaptic potential (or summation of potentials) that does elicit an action potential

Suprathreshold potential

a synaptic potential (or summation of potentials) that does elicit an action potential. Synaptic Attenuation - EPSPs in dendrites obey cable properties and their amplitudes will decrease along the length of the dendrite. See lecture 6 for cable properties.

subthreshold potential

a synaptic potential (or summation of potentials) that does not cause depolarization above threshold above action potential potential

Subthreshold potential

a synaptic potential (or summation of potentials) that does not cause depolarization above threshold above action potential potential.

rough endoplasmic reticulum (ER)

a system of membrane stacks with many ribosomes attached. The rough endoplasmic reticulum is responsible for the synthesis of proteins and is enriched in neurons with long axons compared to other cell types

Rough endoplasmic reticulum (ER)

a system of membrane stacks with many ribosomes attached. The rough endoplasmic reticulum is responsible for the synthesis of proteins and is enriched in neurons with long axons compared to other cell types.

Excitatory postsynaptic potential (EPSP)

a transient depolarization of the membrane potential as a result of the activation of an excitatory chemical synaptic. An EPP is an EPSP at the NMJ.

Aplysia

a type of sea slug used as an experimental animal to study the molecular underpinnings of behavioral learning or plasticity. A relatively simple circuit causes a reflexive retraction of the gills when the animal's siphon is touched. This response and the underlying synaptic strengths can be modulated.

What is alpha bungarotxin?

a venom compontent blocking the AChR. It causes paralysis, respiratory failure and death

Which one of the following statements about EPSPs is true? a) their shape is altered by concurrent synaptic inhibition b) their amplitudes always sum in a linear way c) they have a slow rise and fast fall d) they prevent neurons from reaching action potential

a) their shape is altered by concurrent synaptic inhibition

delay after the initiation of an action potential when it is impossible to initiate a second action potential

absolute refractory period

Emotional smile

accessory motor areas in prefrontal cortex and ventral motor areas in prefrontal cortex and basal ganglia; extrapyramidal pathway through the reticular formation in the brain stem

NT found at autonomic ganglia, autonomically innervated organs, NMJ, and at some CNS synapses

acetylcholine

why do we need nodes of ranvier?

action potential "recharges" here: Na+ channels are concentrated here

1 afferent in spinal cord: what kind of potential? Local/propagated? AM or FM? Analog (graded) or digital?

action potential; propagated; FM; digital

motor neuron axon: what kind of potential? Local/propagated? AM or FM? Analog (graded) or digital?

action; propagated; FM; digital

muscle fiber: what kind of potential? Local/propagated? AM or FM? Analog (graded) or digital?

action; propagated; FM; digital

anterior and posterior ends

activate transcription factors that determine neuronal identity

cell death

active program held in check by trophic factors

synaptic rearrangement

activity dependent especially during early post natal critical periods

synaptic cleft

actual space between cells

Transgenic Mouse

added genes

NGF

affects growth and survival of a few types of neurons

Caliber

affects the amount of attenuation; the fatter the dendrite, the less attenuation (because lower internal resistance)

What kinds of tricks allow impressive feats of memory?

affiliate memories with a sequence sounds or unusual sounding syllables remind mnemonists synthesia - mixed modality perceptions triggered by one sense

In most (adult!) cells, the resting membrane potential is slightly NEGATIVE vs. the Cl- equilibrium potential (OF -65mV)

akin to the ionotropic case of rhe resting membrane potential being very NEGATIVE vs. the Na equilibrium potential so both cause an influx of the ions down their concentration gradient.

why is the EPSP shape not symmetrical (has fast rise, slow fall)

all channels open at the same time, but close randomly

What brain functions are divided by corpus callosum section?

all cross talk between hemispheres conscious perception of objects in each hemisphere restricted only to that hemisphere Right Mute Hemisphere

how do AChRs open and close

all open at the same time (synchronous release of ACh) and each closes randomly

What is reciprocal inhibition?

allows join movement by preventing contractions at the same time -- one muscle will activate, the other relaxes

Why are antagonistic (opposite sign) centers and surrounds useful?

allows the retinal ganglion cell to respond best to certain features, enhances sensitivity to contrast and edges

Divergence

allows the whole brain to attend to even miniscule signals

divergence

allows the whole brain to attend to even miniscule signals

like ACh, Dopamine, norepinepherine, and serotonin are categorized by first

almost exclusively metabotropic (their receptors are coupled to G proteins and thus modulate the effects of faster effects of ionotropic receptors

G Protein

alpha beta and gamma, together called G proteins because they bind to GTP binding of ligand affects them often enzymes that generate second messengers

Lower motor neuron

also called alpha motor neuron innervates extrafusal muscle fibers final common pathway for all motor behavior cells mostly in ventral horn of spinal cord

Diameter

also known as caliper. As diameter increase, Rm decreases, Ra decreases and Cm increases. Ra is proportional to the radius2, whereas Rm and Cm are proportional to the radius.

Myotatic stretch reflex

also known as the knee-jerk response. Stimulating the stretch receptors in the quadriceps muscle initiates a receptor potential which then triggers an action potential in the sensory neuron. The action potential travels up the axon to the spinal cord where the sensory neuron makes a synapse with a motor neuron, causing an action potential in the motor neuron axon. The action potential in the motor neuron travels down the leg to the synapse onto a muscle fiber and triggers a muscle contraction and behavioral response (leg extension).

Slit

also secreted by midline cells

visual impairment akin to blindness but with no physical problem except weak muscles of the eye

amblyopia

units for current

amperes (A)

location of fear in humans

amygdala

increased blood flow in depression

amygdala, medial prefrontal cortex, area 25

apoptosis is a passive or an active process?

an active process

Action potential

an actively propagated impulse that conveys information across long distances. Action potentials are considered unitary or "all or none" such that the size and duration of each action potential remains constant. Details will be covered in later lectures.

Caffeine

an adenosine receptor antagonist meaning it blocks adenosine receptors allowing neurons that regulate arousal to remain active because they are not inhibited by adenosine!---adenosine builds up but cannot bind to receptors.

What is chlorpromazine and what is its main clinical use?

an antipsychotic drug that looks and acts alot like Dopamine - binds to and inhibits D2 Dopamine receptors

SM

an artist with Urbach-Wiethe disease which caused bilateral destruction of the amygdala could not recognize frightened faces and was fearless

Reflex

an automatic (unlearned, involuntary, and sometimes unconscious) response to a stimulus.

describe and give an example of a reflex

an automatic (unlearned, involuntary, often unconscious) response to a stimulus. Ex = myotatic stretch response & gag reflex

reflex

an automatic response to a stimulus

What is Wallerian degeneration?

an axon will die after being cut off from the soma occurs distal to cut site (the part of the axon that is separated)

Graded potential

an electric signal that changes the membrane potential in a continuous manner (oppose to unitary, or "all or none" manner) typically in a small region of a neuron. Graded potentials can differ in size, shape, or duration, depending on the stimulus and response properties of the responding neuron.

Action Potential

an electrical signal generated by neurons which arises from dramatic changes in ion conductance. A rapid depolarization is followed by a rapid hyperpolarization. This signal propagates along the axon (Lecture 7) and allows for long-range transmission of information.

Stimulus

an extrinsic or intrinsic signal that causes a response. In sensory systems, the nature of the stimulus is specific to the sensory modality and the type of sensory receptors activated.

In depressing synapses, the first action potential led to

an increase in [Ca2+] in the presynaptic terminal that was sufficient to cause release of many of the docked vesicles.. Thus, fewer vesicles are available to be released in response to a subsequent action potential (n) Depressing synapses often have effective calcium buffers and little left-over Ca2+; thus the release probability may not be much different than for the first action potential

Sensitization

an increase in the magnitude of a behavioral response to a stimulus after a separate, often noxious stimulus has been applied. In Aplysia, pairing a shock to the tail with stimulation of the siphon, causes a increase in gill retraction when then stimulating the siphon alone.

Capacitor

an insulator (i.e. cell membrane), separating two conducting materials, that can store charge. In neurons, capacitance determines how quickly the membrane potential can respond to changes in current.

Amyloid precursor protein (APP)

an integral membrane protein expressed in many tissues and concentrated in the synapses of neurons. Its primary function is not known, though it has been implicated as a regulator of synapse formation, neural plasticity and iron export. APP is best known as the precursor molecule whose proteolysis generates beta amyloid (Aβ), a polypeptide containing 37 to 49 amino acid residues, whose amyloid fibrillar form is the primary component of amyloid plaques found in the brains of Alzheimer's disease patients

Anion

an ion with a net negative charge. Chloride (Cl-) is the primary important anion for cellular physiology.

Cation

an ion with a net positive charge. Potassium (K+), sodium (Na+) and Calcium (Ca2+) are the important cations for cellular physiology.

increased leptin means increased

anorectic peptides

sham rage

anterior hypothalamus

Define anterograde and retrograde amnesia

anterograde - for events after a trauma (EG HM after 1953) retrograde - events prior to trauma

receptive fields of ganglion cells

are circular and had two concentric and antagonistic parts. He found two kinds of cells, which differed in the activation or inhibition by centrally applied illumination. He named the former ON-center and the latter Off-center cell. He explained this dichotomy on the basis of the effects of excitatory and inhibitory neural inputs to the ganglion cells.

Nicotinic ACh receptors

are excitatory in neuromuscular junction

It is estimated that 80% of all neurons

are glutamatergic

Declarative or explicit memory

are memories that are available to consciousness and can therefore be expressed in language (a phone number, a picture, an event). Sometimes divided into episodic (events) and semantic (facts). Semantic is the only kind before ~2yrs of age.

Procedural or implicit or non-declarative memories

are not easily described with language. They are basically skills and learned reactions that are typically retrieved unconsciously (how to type, how to ride a bike)

Metabotropic receptor-mediated responses

are relatively slow and long-lasting. They usually serve to modulate the effects of fast synaptic transmission.. Have to do more with your general behavioral state-Alertness, happiness, etc.

Pyriform cortex

area of cortex that responds to olfaction information and a target of mitral and tufted cell axons.

Hippocampus

area of the mammalian brain, located in the temporal lobe, that is particularly important in memory formation and/or retrieval.

Active zone

area on the presynaptic neuron where vesicles fuse with the cell membrane to release neurotransmitter. Postsynaptic density - structures on the post- synaptic neuron that contains neurotransmitter receptors and associated cyto-skeletal elements.

How do cortical projection neurons migrate to their destinations? (Where do they arise, where do they go, and what guides do they use?)

arise in ventricular zone go to the right places for their function - inside out birth order and laminar position guided by radial glia

Nicotine acts

as a substitute for ACh (it is an agonist)-If nicotine is applied we also see post synaptic potential nicotine is an agonists for the nicotinic Ach receptors while curare blocks these receptors (it is an antagonist)

Place cells

as an animal enters an area, some hippocampal cells fire action potentials

salience network

associated with attention and executive processes involved in encoding and retrieval

which kind of glial cell aids in maintaining the appropriate chemical environment of the brain

astrocyte

which type of cells form scar tissue and inhibit re-growth in the central nervous system?

astrocytes

Glial (astrocytic) scar

astrocytes at sites of injury proliferate and deposit scar tissue this scar tissue blocks axon growth and contributes to poor regeneration

When is the driving force on K+ the highest

at the equilibrium potential for Na_

Ion

atoms or molecules with a net electric charge. When salts dissolve in water the ionic bond that holds the atoms together break leaving the ions soluble in water.

chemotax

attracted by secretions

chemotropism

attraction to NGF

Chemotropism

attractive cues that cause axons to grow in one direction (eg NGF)

Midbrain

auditory and visual centers e.g.. unconscious vision, eye movement and startle relaxes, motion sensitivity

what do aphasias tell us about brain pathways

auditory area talks to Wernicke's, then sends to arcuate fasciculus then Broca's to motor to produce speech

hypothalamus

autonomic nervous system and pituitary gland; unconscious drives

declarative memory

available to consciousness and can be expressed in language

quantal content equation

average EPP/average mEPP

Flexor reflexes

avoid noxious stimuli; when you put your hand on a hot stove..

caudal

away from the face

which cable property is the most powerful

axial resistance (radius ^2)

List the three classes of skeletal muscles

axial, proximal, and distal...... Axial: deal with back, neck, and ribs . Proximal: control where the limbs are in space (girdle). and Distal: many and they get progressively smaller the further you get into the periphery

Axon VS dendrite

axon - long neurite extends from soma, little to no protein synthesis, conduct electrochemical impulses away from the cell body of neurons, transmit signals dendrites - branches, impulses received by dendrites via synapses, function as a cell's antennae studded with many synaptic terminals

what part of the neuron has the lowest threshold

axon hillock

often is myelinated (axons/dendrites/both/none)

axons

synthesize little to no proteins and thus depend on microtubule dependent transport mechanisms (axons/dendrites/both/none)

axons

typically has presynaptic terminals (axons/dendrites/both/none)

axons

typically, only one process originates form the cell body (axons/dendrites/both/none)

axons

What happens to the postsynaptic sites that are vacated by pruned axons during development?

axons compete for postsynaptic sites, and the remaining axon takes over the site vacated by losers

chemoaffinity hypothesis

axons seeking address related to recognition molecules

what is the corpus calosum made of?

axons that connect the two brain hemispheres

List 6 emotions

calm sadness anxiety anger aversion surprise reverence

agonists cause (convulsions/calming)

calming (more chloride conductance)

How can studies of identical twins reared apart help disentangle genetic and environmental determinants of behavior?

can control the affect of environment - susceptibility and causal genes

Stem Cell

can divide to produce at least one daughter cell just like itself (or) turn into a more differentiated cell involved in neurogenesis

AJ

can remember everything

wernicke's aphasia

can speak fluently, but it's gibberish. fluent word production, impaired comprehension, impaired repetition

broca's aphasia

can understand, but can't produce. impaired word production/repetition, preserved comprehension

Why can't axons make proteins on their own?

can't make their own proteins, all proteins come from the soma I I An axon cannot be self sufficient since if there was a mistake the axon would only take up energy and space since it cannot pass information -If an axon is cut from their soma, Wallerian degeneration occurs distal to the cut site

Which step happens first in normal synaptic transmission? a. SNARE mediated vesicle fusion b. Opening voltage gated calcium channels c. Recycling of synaptic vesicles d. Neurotransmitter release

b. opening voltage gated calcium channels

If there is no driving force, as the conductance for an ion increases _____. a. the current for that ion also increases b. the net current for the ion is 0 c. the capacitance for that ion decreases d. resistance for that ion also increases

b. the net current for that ion is 0

ependymal cells

barriers; neural stem cells

motor activities coordinated from hypothalamus to

basal ganglia

phonemes

basic sounds from which words are made

Soma

basically the cell body itself. the cytoplasm contains: K+ rich salt solution the nucleus (genes) Organelles (e.g. Golgi, mitochondria) Separated from outside by the cell/plasma membrane (site of transmembrane potential gradient) LOTS of ribosomes on the rough endoplasmic reticulum Nissl Substance - site of protein synthesis - large granular body in neurons made of RER with rosettes of free ribosomes Polyribosomes make proteins for the cytoplasm

astrocytes

bbb, take up Its, app substrates, NF

Why might our memory of normal events in our day to day lives be much easier to remember?

because context matters - emotional value

why can EPSPs use temporary summate

because of the long delay course of EPSP

why is the NMJ such a reliable synapse?

because the quantal content is so high, evoked release muscle always depolarizes the muscle above action potential threshold

Henneman's Size Principle.

beginning with smallest/weakest and ending with largest/strongest needed to accomplish the task/action. Motor Neurons generate force by this principle.

ventral view

below angle

drugs that affect inhibition

benzodiazepines (anti-anxiety: Xana, anti-seizure, sleep aids: Ambien) barbiturates (truth serum, capital punishment) alcohol neurosteroid general anesthetics

Smaller Receptive Field.....

better for detection of fine stimulus (bigger receptive field -> not as likely to detect fine changes)

Spike-timing-dependent plasticity (STDP)

bidirectional changes in synaptic strength induced by varying the relative timing between the presynaptic and postsynaptic action potentials (spikes). Depression is induced when the EPSP arrives after the postsynaptic neuron spike. Potentiation is induced if the EPSP arrives before the postsynaptic spike.

Kluver-Bucy syndrome

bilateral removal of the medial temporal lobes in monkeys; profound tameness and fearlessness

Olfactory transduction pathway

binding of an odorant molecule to a olfactory receptor activates a G-protein (Golf) that in turn activates adenylate cyclase. Adenylate cyclase increases the concentration of cAMP which in turn activates a cAMP-gated cation channel and depolarizes the neuron.

Phototransduction

biochemical process by which light is converted to an electrical signal within photoreceptor cells. In rods, when a photon converts the 11-cis retinal into all-trans retinal, the rhodopsin molecule also changes shape and activates a secondary messenger (transducin).

examples of environmental factors for schizophrenia

birth trauma, virus infection during pregnant, childhood environment

Bitter, Sweet, + Umami

bitter/sweet/umami bind to GPCRs -> second messengers -> Cation channels -> depolarize cell -> release neurotransmitter

Unvoluntary movements

blinks can be suppressed voluntarily for only a short time.

Picrotoxin

blocks the GABA a receptor eventually lead to death

mechanism and effect of ouabain

blocks the Na/K pump; in the presence of it, the membrane potential slowly increases and reaches and stabilizes at 0mV

Antagonist

blocks the receptor

integrin is on the axonal ___

body itself

is usually branched (axons/dendrites/both/none)

both

How does botulinum toxin lead to respiratory failure?

botulinum toxin is an enzyme that very specifically cleaves and inactivates SNARE proteins -- a SNAREopathy - and causes paralysis

how does botulinum toxin lead to respiratory failure?

botulism is an enzyme that cleaves and thus inactivates the SNARE proteins, decreasing NT release. Botulinum inhibits the release of acetylcholine. Botulism leads to paralysis

where does GABA go

brain

autonomic réponse coordinated from hypothalamus to

brain stem and spinal cord

Upper motor neuron system

brainstem + cerebral cortex neurons essential for initiation of voluntary movements

afferent neuron

bringing information in from PNS to CNS. Sensory neuron because the information it brings is related to a stimulus

what does the spinal cord do?

brings signals to and from the brain and controls reflex activities

Optic tract

bundle of retinal ganglion axons after the optic chiasm. Each nerve contains axons from both eyes, just 1 visual field, contralateral to the tract.

Optic nerve

bundle of retinal ganglion axons that sends visual information from the eye to the brain before the optic chiasm. Each nerve contains axons from 1 eye, both visual fields.

Alpha

bungarotoxin - competitive agonist for nAChRs that are purified from snake venom. α- bungarotoxin specifically binds to and blocks the receptor.

Metabotropic Receptor

Slow, G protein coupled receptor changes metabolism indirect membrane protein that leads to the generation of an intracellular molecule - a second messenger that goes to the channel

Second Messenger

Small molecules that affect channels (or something else) one particularly important one is Cyclic AMP (which is generated from ATP by adenylyl cycla, a G protein) that activates another enzyme, protein kinase A, which can activate many proteins, including channels

miniature end plate potential (MEPP)

Small, spontaneous depolarization of the membrane potential of skeletal muscle cells, caused by the release of a single quantum of acetylcholine. Happens after a vesicle in the presynaptic terminal spontaneously fuses with the presynaptic cell membrane.

Olfactory Bulbs

Smell

What is channelrhodopsin and how is it used to link neuronal activity to behavior?

Sodium channel that is gated by light When you shine light on it, it lets sodium through Using genetic methods, you can insert rhodopsin into neurons and when you shine light on them, they fire Called optogenetics

List the 4 main compartments found in most neurons.

Soma Axon Nerve Terminal Dendrites

Motor PNS

Somata and dendrites in the spinal cord Ventral (motor) horn -> Motor Neuron -> Muscle Axon connects to muscles

What is the relationship between sour taste and the taste of carbonation?

Some sour taste cells have an enzyme called carbonic anhydrase on their surface. It catalyzes an equilibrium with CO2 and H2O on one side and H+ and HCO3- on the other. The protons (H+) activate the sour receptor. So, the taste of carbonation is sour plus fizz.

What does "conductance" mean in neuro?

Sort of equivalent to the permeability term for an ion in the GHK equation. It is the relative ability of an electrical charge to migrate from one point to another, represented by the symbol g and measured in siemens (S). It is the inverse of resistance.

Axon terminal

Specialized endings of the axon that makes synaptic contacts with other cells

Axoplasmic transport

Specialized transport that is faster than diffusion -Use of microtubules -Anterograde motor protein, Kinesin: towards soma -Retrograde motor protein, Dynein: towards the nerve terminals

Frontal Lobe

Speech, Problem Solving, Planning, Decision Making, Emotional Control

Describe the eye rotation experiment? What did it show?

Sperry cut the optic nerve and rotated the eye 180 degrees (anterior now posterior). Once axons regenerated the frog saw the world upside down and didn't recover So the retinal axons must have been seeking an address in the tectum that was related to some identification tag that allowed them to recognize their appropriate target region. He proposed that the tags were chemical in nature and thus recognition molecules

GABA : GLYCINE equals brain :

Spinal Cord

Reason for diversity and complexity of brain structure

Splice variants Variety of introns in the mRNA Difference in regulation of mRNA throughout different regions of the brain

What is the difference between a state of equilibrium (as in Nernst) and a steady state (as in GHK)?

State of eq. = net efflux and influx of an ion is equal Steady state = maintains a steady concentration within and outside the cell but the efflux and influx of ions are not necessarily equal

Embryonic stem (ES) cell

Stem cells that can give rise to all the cells of an embryo and even to a whole embryo; They can divide to form more stem cells and they can differentiate into specialized cells. Take them out and grow them in culture and do the homologous recombination and then select the cells with the recombinant DNA. By using homologous recombination in ES cells, one generates a mutant cell that can give rise to a mutant embryo

neurological mechanism of conditioned fear response

Strong pain input, depolarizes cell. Axon hillock region is at synapse. All dendrites depolarize. Weak input is also glutamatergic--ligand gated by glutamate but also voltage gated. Only opens if the cell is already depolarized. Allows a lot of calcium to enter cell. If they are synchronously activated, new receptors. Tone that was originally weak is now strong

Give 3 differences between rods and cones - one structural, one molecular, and one functional

Structural -- Rods have longer outer segment. Cone's outer segment is shorter and tapered (cone like) Molecular -- cones have photopigments giving sensitivity to red, blue, and green. Rods see everything is shades of gray Functional -- cones for photopic/day/color vision with high acuity. rods for scotopic/night vision with low acuity.

Cytoskeleton

Structure and protein transport

Convergence

Summation of multiple axonal inputs converging on the same postsynaptic neuron may bring ideas to threshold

Dura Mater

Surrounds and supports the cranial sinuses, and carries blood from the brain to the heart.

Long-Term Depression

Sustained weakening of synaptic connections caused through low rate stimulation for long periods

What is the "fight or flight" response and what part of the nervous system orchestrates it?

Sympathetic ANS selective energy expenditure for intense activity (catabolic) Adrenergic Uses norepinephrine

Do postsynaptic cells induce the differentiation of presynaptic elements or vice versa?

Synapse formation is a multi-step process involving acquisition of many pre/post synaptic features and their perfect apposition. Differentiation: organizing and coordination pre- and postsynaptic specializations

AMPA Receptor Phosphorylation plays a role in

Synaptic Plasticity

What are synergistic and antagonistic muscles?

Synergistic muscles - muscles that work together with another muscle to achieve a desired goal, similar functions Antagonistic muscles - act in opposition to each other, unrelated functions

List 3 different levels by which neuroscientists deconstruct the brain?

Systems (visual, motor, autonomic) Cells (particularly neurons) Molecules (particularly gene products)

What can and cant a T1R1 knockout mouse taste? T1R2? T1R3?

T1R1 - Can not taste umami. Can taste all other tastes T1R2 - Can taste all tastes T1R3 - Can not taste umami. Can taste all other tastes SO T1R1 and T1R2 are in different cells but all T2Rs are in the same cell

growth cone

TIP OF THE GROWING AXON, VERY SPECIALIZED STRUCTURE

What controls development?

TOP-DOWN CONTROL LIKE AN AIR TRAFFIC CONTROLLER, CELLS PROGRAMMED TO DO THEIR PART LIKE ROBOTS, BOTTOM-UP SELF-ORGANIZATION SO THAT CELLS WOULD NEED TO BE IN COMMUNICATION TO MAKE SURE EACH DOES THE RIGHT THING FOR THE COMMON GOOD

hypothalamus releases ___ to pituitary to release ____ (thyroid eventually releases thyroxin)

TRH; TSH

With reference to thermoregulation - where and how does the brain sense temperature?

TRP channels in the skin and hypothalamus members of the TRP channel family -- They are cation-selective (depolarizing), voltage independent, gated by temperature, mechanical deformation

toxin that blocks voltage gated sodium channels found in pufferfish

TTX (tetrodotoxin)

Action potential: TTX or alpha BTX AChR: TTX or alpha BTX

TTX; alpha BTX

Briefly describe the taste organs of the tongue

Taste buds are packed together in taste papillae on the surface of the tongue taste receptor cells form synapses onto gustatory fibers, which project to the gustatory ganglia, and then onto the brain

Parietal Lobe

Taste, Touch, Movement

What are our main drives?

Temperature control, Hunger, sex, thirst, sleep, etc.

What was the test done to determine how bitter/sweet/umami is tasted?

The quantity of 2nd messengers was monitored as different compounds were washed over the cells w/ T2Rs GPCR Result: T2Rs responded to bitter, T1R1 + T1R3 = sweet, T1R1 + T1R3 = umami

How are tics in Tourette's syndrome similar and different from normal eye blinking?

The tics in Tourette's syndrome are of a similar nature: the pathological urge can be voluntarily resisted but not too long. Eventually the tic will show itself and in this disease it can be very disruptive to normal social activity

Inside out migration

The time at which neuron is born dictates what layer it will be in; childhood epilepsy is a result of improper migration

How did genetic studies help show that the AB peptide is a cause of Alzheimers?

Three of the genes that commonly account for Alzheimers genetic component are APP Presenilin 1 and Presenilin 2

during, but also after an animal has run on a track?

Three place cells (blue, red and green) in the hippocampus fire as a rat runs on a linear track. The colored lines represent firing of place neurons. When the rat is rewarded with food at the end of the linear track the firing sequences replay in reverse (that is, green, red, blue). Telling animal how to get back home? When sleeping- the sequence also replays—but this time in the forward direction (as if reliving the experience)

Homologous recombination

To generate in a test tube a broken/mutated version of that gene to be knocked out and then insert targeting vector into a cell. In a small fraction of cases, the vector will recombine with the native gene replacing it in the genome. Make version of the gene you want.

family? What do they sense?

Two groups of GPCRs: T1Rs (#1-3) and T2Rs (#1-~40)

association with each other and what are the consequences of this change?

Two main components are opsin (GPCR) and retinal (ligand)

What happens to receptive field properties beyond V1?

Two major pathways out of V1 - What and Where As you move progressively higher into the sensory processing centers of the brain, the receive fields get more complicated

Presenilin

Two of the 3 genes (Presenilin-1, Presenilin-2, and APP) that account for the most common genetic components for Alzheimers

G-protein coupled receptor (GPCR)

Type of metabotropic receptor with 7 transmembrane domains that interacts with G proteins. GPCRs are a diverse group with each subtype activated by one of a variety of ligands (light, specific neuropeptides, sugars, or lipids).

hemispatial neglect

Unawareness of the existence of left space (including left body parts) due to lesions in right hemisphere

What is a brain machine interface? Why might our motor system have so little trouble using robotic arms?

Ways to skip the detailed parts of the pathways - go start from the cortical neurons responsible for planning/initiating the movement to the robotic movements themselves because the qua we plan movements is pretty independent of the way in which the movement is executed

James-Lange Theory

We experience emotion in response to physiological changes in our body. We feel sad because we cry not the other way round. The physical changes are the emotion.

signals?

When the synaptic target of a neuronal type is removed during development, fewer neurons are

What are nodes of Ranvier and why are they necessary?

Where the action potential "recharges" Nodes of Ranvier are the depolarized, little regions 100s of ums apart in a myelinated axon Na+ channels concentrated at nodes. K+ channels concentrated along internodes Lead to saltatory conductance -- ion flow across the membrane occurs only at the nodes of Ranvier. As a result, the action potential signal jumps along the axon, from node to node, rather than propagating smoothly, as they do in axons that lack a myelin sheath.

What are the main constituents of white matter? Gray matter?

White matter - myelinated axons (white bc myelin!) Gray matter - synapses, dendrites, somas

Describe a mechanism by which heterosynaptic facilitation could underlie sensitization

With an aplysia, after habituation, if you touch another part and then come back to the siphon, the signal will return to normal Touch is less likely to be another repetition of a harmless stimulus Touching the head activates another interneuron that had a modulatory synapse on the sensory neuron through heterosynaptic facilitation

does inhibition reduce membrane resistance?

YES (chloride channels open up)

Can specific memories be lost and others retained? What is the evidence?

Yes, peculiarly specific memory impairments suggest a high degree of spatial locality of some memories. Remembering colors of other people's possessions but not his own

What would happen if one cell responded to color, shape, and movement?

You would never know which of the three stimuli caused it to respond

Corticofugal pathway

Mysterious...starts from cortex -> thalamus 80% of info in LGN is from primary visual cortex, not the retina out put of thalamus is the primary visual cortex

neural connections are specific

NERVOUS SYSTEM IS PARTITIONED INTO MANY SEPARATED STREAMS, THERE ARE TOPOGRAPHIC MAPS WITHIN EACH, NOT RANDOM CONNECTIONS

Mechanisms undergoing Long-Term Potentiation

NMDA receptors

If a membrane of a cell is permeable to all ions, is there a point when ions finally stop flowing across the membrane?

NO - ions are just jostling around, bumping into the membrane/permeable channels and the diffusion is due to the probability of a certain type of ion hitting the membrane on one side rather than the other -- equilibrium is reached when there is equal flux in both directions

What are the 9 steps in the development of the nervous system?

NRNMDPASS: Neurulation, Regionalization, Neurogenesis, Migration, Differentiation, Programmed Cell Death, Axon Guidance, Synapse Formation, Synaptic Rearrangement

ions that have equal conductances through an AMPA receptor

Na+ and K+

Neuron Action Potential mechanism

Na+ enters through Na+ voltage gated channels during rising phase, gates close/inactivate, K+ voltage gated channels open, K+ flows out through that and leak channel during falling phase. Stops when more negative inside, K+ channels slowly closes.

What are the inside and outside concentration for Na+, K+, Cl-, Ca++ in a typical cell

Na+ in = 15 mM Na+ out = 150 mM Eq. Pot. = 62 mV K+ in = 100 mM K+ out = 5 mM Eq. Pot. = -80 mV Cl- in = 130 mM Cl- out = 150 mM Eq. Pot. = -65 mV Ca++ in = .0002 mM Ca++ out = 2 mM Eq. Pot. = 120 mV

what happens when the muscle is stretchedd?

Na+ is let in, leads to change in receptor potential

NMDA receptors are permeable to

Na+, K+, and Ca2+Influx of Ca2+ through NMDA receptors Calcium acts as a second messenger, activating several intracellular signaling cascades

Glutamate

Nearly all excitatory neurons in the central nervous system are glutamatergic

Why is LTD needed?

Need to selectively weaken some sets of synapses to prevent them from reaching a level of maximum efficacy I Difficulty to encode new information

Coincidence detector

Needs pre/post synaptic neurons to be active

Neurons

Nerve cells -long distance electrical signaling and intracellular communication through synapses -transmits information through an input of signals convergence: # inputs to a single neuron divergence:# targets innervated by a neuron

Dynamic Polarization

Nerve cells are "polarized": receive info and send it to distant locations -Information arrives from dendrites, through the cell body to the axon and to its axon terminals.

Describe how attractive and repulsive cues guide axons across the midline.

Netrin is secreted by ventral midline of the spinal cord cells. Axons with netrin receptors chemotax to midline (grow towards the midline). Try to find highest density of netrin. Slit is also secreted by the midline cells, Axons that approach the midline are induced to upregulate the slit receptor (Robo) on their membranes. Axons expressing the Robo receptor are repelled by Slit. Robo thus prevents axons that cross the midline from being attracted by Netrin to cross again

neural crest arise.

Neural tube becomes the central nervous system

Adult neurogenesis

Neurogenesis continues at low levels in a few parts of the adult brain - hippocampus and olfactory bulb, but not cortex. Thus, some neural stem cells persist in the adult brain.

How were EPSPs discovered?

Neuromuscular junction

Model system for studying synaptic transmission

Neuromuscular junction

developing neuromuscular system?

Neuromuscular junction, cerebellum, retinogeniculate pathway (RGC to LGN), autonomic ganglia all known to have extra axonal branches that are pruned in development- probably everywhere

have to do with memory?

Neurons and navigation: position memory because of place and grid cells

What is Hebb's postulate?

Neurons that dire together wire together

Columnar organization

Neurons within a column of V1 (from layer 2/3 down to layer 6) have the same tuning (e.g. same orientation selectivity), and there is an orderly shift in orientation across a small area of V1. Additionally, there are alternating columns of L or R ocular dominance.

Is a neuron alive? Is it different from an animal being alive? If so, how?

Neurons/cells are the basic unit of all multicellular organisms -- they are alive and can die. Kind of like protozoa swimming in a very weird pond.

The quantal hypothesis of neurotransmitter release

Neurotransmitter is released in discrete packets, or "quanta".

Active zone

Neurotransmitters are released by synaptic vesicle exocytosis at the active zone of a presynaptic nerve terminal

9 main steps in mammalian neural development?

Neurulation. Regionalization. Neurogenesis. Migration. Differentiation. Apoptosis. Axon growth and guidance. Synapse formation. Synaptic Rearrangement

Nicotinic ACh receptor

Nicotinic ACh receptors are found at the neuromuscular junction

Do excitatory synaptic potentials sum linearly? Why?

No -- synaptic potentials of different axons sum but in a nonlinear way because the closer the membrane potential gets to reversal potential (~10mV), the lower the net driving force. And a synapse cant depolarize the membrane beyond the reversal potential so 10mV is a LIMIT and is never actually attained. SO additional input has less effect

Axon

No RER and few Polyribosomes -- rely on soma/axoplasmic transport Initial segment = axon hillock unique to neurons length and caliber varies makes the majority of neuron's volume

Are there unique genes unique to individual cell types?

No genes are unique to one cell type

Does each muscle have its own nerve from the spinal cord?

No, Lots of muscles all innervated by same branched nerve

By what size measure is human brain size at one extreme?

Relative to other animals with the same body size our brains are exceptionally large but we are not the biggest brained animals or have the biggest brain:body ratio

By what size measure is human brain size at one extreme?

Relative to other animals with the same body size, our brains are exceptionally large (encephalization: braininess)

the dark current

Release of transmitter from photoreceptors hyperpolarizes ON bipolars so light, which decreases transmitter release, depolarizes and activates them... remember

What is meant by growth cone collapse? How could such signals be used to guide axons?

Repulsive signals cause collapse - the literal withdrawal of the seeking growth cone

Parasympathetic ANS

Rest and Digest Cholinergic system Neurotransmitter = Acetylcholine

Membrane Voltage changes in action potential

Resting is -60mV, -40 mV is threshold, goes up to 60mV at overshoot (1ms), goes down to -80mV (2ms) at undershoot then back to -60mV(3.5ms).

Input Specific

Restricted to activated synapses of a cell I End of the synapses in the hippocampus can store info

What is retinopy? What part of the visual map is magnified?

Retinopy is a 2 dimensional surface of retina mapped (topographically arranged) onto two dimensional surface of the subsequent structures (thalamus and cortex). Center few degrees of visual field are over-represented (magnified) for better acuity in the center of the visual field.

Define anterograde and retrograde amnesia.

Retrograde amnesia is a complete blank for events prior to trauma

when cells near the midline, the receptor for Netrin/Robo gets unregulated for Slit

Robo

functional.

Rods have a long, cylindrical outer segment, containing many disks

What is the chemoaffinity hypothesis and who suggested it?

Roger Sperry and his Eye Rotation Experiment the retinal axons were seeking an address in the tectum that was related to some identification tag that allowed them to recognize their appropriate target region. He proposed that the tags were chemical in nature and thus recognition molecules

Nssl Bodies

Rough ER bodies

How are tics in Tourette's syndrome similar and different from normal eye blinking?

SIMILAR IN THAT HARD TO RESIST, DIFFERENT IN THAT MORE THAN USUAL

protein complex that mediates vesicle fusion

SNARE complex

radiation, and the primary visual cortex.

SO IMPORTANT!! KNOW THIS

eye rotation experiment

SPERRY CUT THE OPTIC NERVE AND ROTATED THE EYE 180 DEGREES IN THE SOCKEY SO THAT WHAT WAS UP WAS NOW DOWN AND WHAT WAS ANTERIOR WAS NOW POSTERIOR. IT SHOWED THAT ONCE SEVERED AXONS REGREW, THE FROG SAW THE WORLD UPSIDE DOWN AND DID NOT ADAPT

chemoaffinity hypothesis

SPERRY PROPOSED THAT PHYSICAL CUES GUIDE AXONS AND FUNCTIONAL MOLDING OF RANDOM CONNECTIONS

three general sites where axonal guidance cues originate

SUBSTRATE, OTHER AXONS, TARGET

Which of the gustatory tastes directly depolarizes the membrane of the gustatory sensory neuron, without activating a GCPR?

Salty and Sour

Does each muscle have its own nerve from the spinal cord?

Same proximal nerve may branch to many muscles OR many muscles that are all innervated by same branched nerve

Neuron Doctrine

Santiago Ramon y Cajal -Nerve Cells (neurons) are the base of the brain -Nervous system carries out its functions by passing information from one neuron to the next. -Neurons communicate through synapses, not continuous

Myelinating Glia

Schwann Cells in Peripheral NS Oligodendrocytes in Central NS Form Myelin Sheaths to protect, conduct current/electrical impulse

When there is inhibition, how does the membrane resistance change?

Opening more channels increases the conductance for those permeable ions. By definition a higher conductance means lower resistance.

What are the two main components of rhodopsin? How does light affect their association with each other and what are the consequences of this change?

Opsin (a GPCR) and Retinal (opsin's Ligand) Light causes activation of opsin followed by dissociation of retinal from opsin activated rhodopsin activates a G Protein that G Protein then activates phosphodiesterase, an enzyme that breaks down cyclic GMP Cylclic GMP opens a cation channel (Na+, Ca++) and depolarizes the cell So by activating phosphodiesterase, you deplete cyclic GMP, closing the cation channel and hyper polarizing the cell Since this hyper polarization of the photoreceptors happens when light activates rhodopsin, photoreceptors release transmitter only in the dark

cortex?

Parts of the pathway closer to the retina are all on or off center with antagonistic surround. Maybe convergence of several center surround cells that form a line is the basis of the orientation specificity

, these mechanisms for expelling Ca2+ from the presynaptic terminal are fairly slow...

Past activity of the presynaptic neuron affects its future release properties at short time scales (short-term plasticity)

List 3 phases of decision making for an axon and give an example of each

Pathway Selection (EG ipsi/contra lateral at the optic chaism) Target Selection (EG lateral geniculate vs medial geniculate) Address Selection (EG dendrites of geniculocortical cells)

List three phases of axonal decision making

Pathway selection (E.g. ipsilateral or contralateral at the optic chiasm); Target selection (E.g. lateral geniculate vs. medial geniculate); address selection (E.g. layers 2,3, and 5; Dendrites of geniculocortical cells)

Axon navigation 3 paths of selection

Pathway; target; address

List 3 effects that guidance cues can have on a growth cone

Permissive -> permit growth Attractive -> attract it to grow in direction (e.g. chemotropism) Repulsive -> growth cone collapse

List three effects that guidance cues can have on a growth cone.

Permissive effects: Not being forced but a lot easier to move on a permissive substrate

Draw the basic retinal circuit

Photoreceptors in the outer nuclear layer -> synaptic layer -> Interneurons (horizontal, bipolar, and amacrine cells) in the inner nuclear layer -> synaptic layer -> Retinal Ganglion Cells in the ganglion cell layer -> optic nerve -> brain

What pathways are involved with each of the 2 components of emotion?

Physical expression -- peripheral, autonomic, endocrine, and motor systems by way if subcortical structures - sometimes the cerebral cortex is unnecessary to elicit "sham rage" in cats for example Conscious perception -- cerebral cortex - the limbic cortical structures interact with the hypothalamus via the amygdala

What are the 2 main components of emotion? Provide an example of each?

Physical expression -- tears, blushing, etc. - the emotional state Conscious Perception -- afraid, happy, etc. - sensation or feeling

What are place cells and grid cells? What do they have to do with memory?

Place and grid cells allow position memory and are activated when in certain place - probably for navigation

Post-synaptic density

Post-synaptic membrane differentiation that's the site of neurotransmitter receptor a structure composed of both membranous and cytoplasmic proteins localized at the postsynaptic plasma membrane of excitatory synapses

topographic specificity of the retinotectal projection

Posterior retinal axons project to anterior tectum Anterior retinal axons project to posterior tectum

Describe the topographic specificity of the retinotectal projection

Posterior retinal ganglion cell axons preferentially grow on membranes of anterior tectum and avoided posterior tectum membranes. so there are a large number of recognition molecules in the retinotectal pathway

What genetic distinctions underlie these behavioral differences (in voles)?

Prairie voles have higher levels of receptors for oxytocin and vasopressin in parts of their brains

How could you determine whether homosynaptic facilitation results from pre or post synaptic changes?

Pre synaptic -- change in quantal number (# of vesicles released) Post synaptic - change in number/responsiveness of receptors

Area 6

Premotor cortex; stimulation elicits movement but these are more complex

The effects of acetylcholine released by nerve terminals are mimicked by ionotrophic application of acetylcholine

Preparation bathed in

The Nerve Terminal

Presynaptic part of a synapse

Depression is a pre or post synaptic mechanism

Presynaptic: depletion of readily available vesicles `

.

Prevents tears

Name the 4 primary cortical sensory areas and describe their locations & functions?

Primary Auditory Cortex (in the front of the temporal lobe) - receives impulses from auditory receptors Primary Somatosensory Cortex (in the parietal lobe) - Receives nerve impulses for touch, proprioception, pain, and temperature. Primary Visual Cortex (in the occipital lobe) -Receives impulses from the thalamus when the retina is stimulated. Primary Motor Cortex (in the frontal lobe) - Initiates impulses to skeletal muscles

arise, where do they go, and what guides do they use?)

Principal neurons (ones that send axons out of the cortex) migrate radially from ventricular zone along radial glia. Interneurons migrate tangentially from subcortical areas. Inside-out birth order and laminar position

HM's procedural memories

Procedural memories was not affected at all

What about HMs procedural memory? Why was this different from his declarative memory?

Procedural memory and intelligence unaffected Medial temporal lobe important for declarative but not procedural memory consolidation procedural memory formation can go on without any conscious awareness

memory consolidation defined

Process by which short-term memory passes to long-term memory

Neurogenesis

Progressive restriction of cell fate; cell keeps dividing and specializing until it cannot any more

How are recycled vesicles refilled with neurotransmitter molecules?

Proteins called "transporters" are found in the vesicle membrane and the presynaptic terminal membrane. In the vesicle membrane, transorters take up neurotransmitter molecules from the presynaptic terminal and move them into the vesicle. In the presynaptic terminal membrane, transporters take up neurotransmitter molecules from the synaptic cleft and transport them back into the cell ("reuptake")

Causing plasticity in adolescnence

Put prism goggles on young owls during critical period, remove them when adjustment is complete, re-fit them in adulthood. Found that there is greater remapping than if the goggles were only first fit in adulthood Implication: if you learn several languages when you are young, you can learn languages easier when you are older

Evidence for Calcium Hypothesis

Quantal release of neurotransmitter is proportional to extracellular Ca++. Action potential conducted along axon and into presynaptic nerve terminal, ensuinng depolarization opens voltage-gated Ca channels. I_ca=g_ca(V_m-E_ca) so Ca flows inn even at peak pf depolarization. Intracellular Ca triggers vesicle fusion and neurotransmitter release. Vesicles released proportional to Ca++^4 so 2x more Ca = 16x quanta released. Therefore voltage-dependent calcium entry couples stimulation (presynaptic action potentials) to quantal release of neurotransmitter

Three kinds of movement are in a rough hierarchy: what are they?

REFLEXIVE IS LOWEST, THEN RHYTHMIC, THEN VOLUNTARY

more ____ in neurons than in most other cell types

RER

What is the rough endoplasmic reticulum; where is it found and why is there so much of it (known as Nissl substance) in neurons, especially those with very long axons?

RER = the site of protein synthesis Nissl Substance - large granular body in neurons made of RER with rosettes of free ribosomes LOTS of RER and ribosomes in the soma because the soma has to support the axon (which has no RER and few polyribosomes) longer the axon, more the soma has to support, need more protein synthesis

Define the Neuron Doctrine. Whose idea was it?

Ramon y Cajal also used the Golgi Stain and he proposed the Neuron Doctrine -- that neurons are the basic structural and functional unit of the nervous system. Ramon y Cajal was the artist, Golgi was wrong.

Define imprinting.

Rapid learning that occurs during a brief receptive period, typically soon after birth or hatching, and establishes a long-lasting behavioral response to a specific individual or object, as attachment to parent

List 3 things that can happen to a released neurotransmitter besides binding to a neurotransmitter receptor

Re-uptake into the presynaptic nerve terminal (reuptake) Broken down by synaptic cleft enzymes (enzymatic destruction) Taken up by glia (Glial uptake) Diffusion away

What is reconsolidation?

Recall something, reconsolidate it, refile it update our memories in light of new information and reconsolidate the modified version

Define receptor potential and and action potential

Receptor potential - a stimulus induced change in the membrane potential of a sensory receptor Action potential - a brief fluctuation in membrane potential caused by the rapid opening and closing of voltage gated ion channels, sweep like a wave along axons to transfer info

Synaptic Speed is determined by

Receptor, not transmitter

What feature of reconsolidation suggests a therapeutic approach to PTSD?

Reconsolidation requires protein synthesis - its an active process so might be able to modify and erase the trauma

Three kinds of movements are in a rough hierarchy: what are they?

Reflexive (lowest) then Rhythmic then Voluntary (highest)

The motor hierarchy

Reflexive -> Rhythmic -> Voluntary -> Learned....but then learned movements become reflexive with practice...weird!

Describe the Cannon-Bard theory.

The Cannon-Bard Theory: 1927 Walter Cannon ("flight and fight") and later Phillip Bard proposed that emotional feeling can occur independently of emotional expression.

Initial Evidence for Neuron Doctrine

The Golgi Stain -Staining brains with chemicals used in photography -works through black reaction

Describe the James-Lange theory.

The James-Lange Theory: 1884 William James (James Hall) and Carl Lange. We experience emotion in response to physiological changes in our body. We feel sad because we cry not the other way round. The physical changes are the emotion.

Why does blood flow go up at sites of neural activity as revealed by fMRI BOLD technique?

The Sodium Potassium pump is ATPase (needs energy bc active transport) and so the fMRI BOLD technique would naturally highlight the active intake of more glucose to maintain the concentration gradient

What technical advance did Hubel develop and why was this important?

The Tungsten electrode -- allowed extracellular recording of action potentials in cortical neurons

Second messengers

The activated proteins, often enzymes. Affect channels (cyclic AMP which activates kinase A) *signal amplification

You stare at a yellow square for 30 secs, then move your gaze to a white screen. On it you see an after image. What color is it? Why? What shape? Why?

The after-image will be a blue square because the red and green cones have overfired in the specific boundaries of yellow. Moving your eyes to the white square should trigger all three cones, but since the red and green have been worn out, only the blue cone fires, thus making the "square" look blue.

Receptive field of a visual cell

The area to which a cell is responsive

Mike the headless chicken

showed that all the brain is really doing is activating the spinal cord...not even telling it what to do...you can just depolarize the spinal cord with an electrode and you'll get the same response...shows that conscious processes are not necessary for the moment to moment control of movement

serious depression

shows Increased blood flow in the left amygdala, orbital, and medial prefrontal cortex associated

organizer experiment

shows induction

phenomenon mediated by chloride channels that is defined as an increase in synaptic conductance in the absence of an obvious change in membrane potential that can short-circuit currents generated at adjacent synapses

shunting inhibition

lateral view

side angle

units for conductance

siemens

saltatory conduction

signal jumps from node to node when channels at nodes of Ranvier open

stimulus

signal that causes a response

Frequency coding

since action potentials are unitary in size and duration, the strength of the signal is determined by the frequency of the action potentials. A stronger signal increases the frequency of action potentials (i.e. number of action potentials per second).

Labeled line hypothesis

since individual taste cells have only 1 type of receptor, they are tuned to only category of taste. This segregation of stimuli is continued in throughout much of the taste pathway so neurons in the thalamus and insular cortex (taste region of the brain) also respond to just one category.

axon initial segment

site of action potential initiation, close to the origin of the axon

substrate, other axons, tagets

sites for chemical cues

The _______ is inversely proportional to the density of the fibers supplying an area.

size of the receptive field

Quantal Hypothesis

spontaneous small depolarizations in muscle membrane potential traces, but only near NMJs. The nerve-evoked synaptic potential at the neuromuscular junction looks like a gigantic version of the spontaneous potentials. 1. MEPP amplitude declines with distance from the neuromuscular junction -> Minis arise at the synapse 2. Minis disappear when nerve is removed -> Minis originate in the nerve 3. Minis disappear when inhbitors of acetylcholine action are applied->Minis are caused by the ACh neurotransmitter 4. Minis are mimicked by puffing ~5,000 molecules of acetylcholine at the neuromuscular junction -> Minis are packets of neurotransmitter molecules (i.e. "quanta") spontaneously released by nerve at the NMA 5. Nerve evoked release looks like a very large MEPP -> Synaptic potentials are due to the synchronous release of many quanta, each of which is a multimolecular packet of neurotransmitter

MEPPs are _______ released

spontaneously

Connexon

specialized membrane proteins that connect two cells at gap junctions. Composed of connexin subunits.

NMDA receptors are both ligand-gated and voltage sensitive channels.

specifically, At the resting potential, the channel is blocked by Mg2+ Depolarization drives Mg2+ out of the pore Typically, the membrane must be depolarized by ~20-30 mV to remove the Mg2+ block

lock and key recognition

specificity

Broca's Area

speech -- word production (not comprehension!)

myelin sheath

speeds up signal transmission along the axon

where does glycine go

spinal cord

with age, the neurons lose their

spines

What is a commisurotomy?

split brain, patients with disconnected selves 2 minds in one skull following the corpus callous section

mEPPs are produced by

spontaneous release of NT

system that stays constant over time but requires constant work

steady state

a system that remains constant over time but requires continual work. A good example is a neuron at rest

steady state/dynamic equillibrium

DBS for depression

stimulate Area 25, lowers blood flow, chronically stimulated. positive results, but some are pessimistic

how can you record NMJ synaptic potentials

stimulate motor axon, record intracellularly from muscle fiber while blocking action potential to record only synaptic potential

Wilder Penfield

stimulated cortex and found that the weakest stimulation strengths could give muscle twitches only if the stimulation was localized in M1

what are the components of behavior?

stimulus and response

What 4 cells participate in the patellar tendon reflex?

stimulus stretches sensory receptors in the quadriceps muscle, sends a signal via a sensory neuron that (1)synapses with and excites a motor neuron in the spinal cord which synapses on extensor muscle fibers and cause contraction and (2) excites a spinal interneuron in the spinal cord which then synapses on an inhibitory neuron that inhibits flexor muscles and allows the leg to extend stimulus -> sensory neuron -> dorsal root ganglion -> dorsal horn ->synapses motor and interneuron -> (1), (2) (1) -> motor neuron -> ventral root -> quads contract (2) -> interneuron neuron -> inhibitory neuron -> hamstring relaxes

ways to heal damage (3)

stop apoptosis; neural stem cells; implant

Define strabismus and amblyopia

strabismus - misalignment of the eyes typically due to a weakness in one or another extra-ocular muscle amblyopia - a visual impairment akin to blindness but without any physical problem in the retina or lens

Parallel processing

streams of information related to properties of the visual scenes are dealt with simultaneously by different circuits

Optic chiasm

structure in the midline where the axons from the nasal retina cross to the contralateral side

Lorenz

studied imprinting

laminin is on the axonal ____

substrate

NMDA receptor

subtype of glutamate receptor that is typically permeable to K and Na and Ca. Extracellular Mg++ blocks the pore of NMDA receptors at negative membrane potentials, so the channel acts as a coincidence detector: both glutamate (presynaptic release) and postsynaptic depolarization are required for current to flow through the channel.

AMPA and NMDA receptors are co-localized in the membrane so that

sufficiently large depolarization from AMPA receptor activation can unblock NMDA receptors

convergence

summation of multiple axonal inputs converging on the same postsynaptic threshold

Slow adaptation is better for

sustained changes

Long term potentiation

sustained strengthening of synaptic connections caused by previous patterns of neuronal and synaptic activity. Usually a repeated, high-intensity stimulation of the axons from CA3 cells, connecting to CA1 cells, leads to a strengthening (potentiation) of that synaptic connection. Frequent Ca entry through NMDA receptors causes a signaling cascade that eventually leads to insertion of additional AMPA receptors and even sprouting of additional synaptic connections (spines).

anorectic peptides from the hypothalamus/pituitary stimulate the ___ NS

sympathetic

Neuromuscular Junction

synapse made by motor neurons onto muscle fibers

Subthreshold

synapses located on a distant dendrite branch; even though they give a large depolarization at the site of the synapse, they are subhthreshold

final step (#9) in development

synaptic rearrangment

What is the vesicle hypothesis of neurotransmission and what is a key piece of evidence that supports it?

synaptic vesicles are the structural basis of quanta - they contain neurotransmitter which they release by exocytosis Electron microscopy: Omega figures seen if nerve's fixed right after stimulation. Prolonged, intense stimulation leads to the depletion of vesicles - vesicle recycling and tracer uptake - these tracers provide evidence for recycling and mark the intermediate steps

NMJ: what kind of potential? Local/propagated? AM or FM? Analog (graded) or digital?

synaptic; local; AM; analog

motor neuron dendrite: what kind of potential? Local/propagated? AM or FM? Analog (graded) or digital?

synaptic; local; AM; analog

neuronal circuit

synaptically connected neurons that carry out a specific function

Neuronal circuit

synaptically connected neurons that carry out a specific function (e.g. reflex circuit, visual circuit).

define neuronal circuit

synaptically connected neurons that carryout a specific function

reversal potential of the AChR is due to...

synchronous conductance of several cations

levels of deconstruction

systems, cells, molecules

-concurrent spatial & temporal summation

takes all inputs into account

How do interneurons migrate?

tangentially from subcortical areas

Olfactory bulb

target of the olfactory sensory neuron axons and since there is no olfactory thalamic region, it is the first processing center of the vertebrate brain.

trophic theory of neuronal survival

target secretes neurotrophic molecule needed for neuronal survival

Taste transduction

tastants binding to the taste receptors causes depolarization in the taste cells and eventually triggers an action potential either through direct depolarization through selective ion type receptors or a signaling cascade.

Taste papillae

taste buds are organized into these

Tangles are ___ aggregates associated with

tau; Alzheimer's

End Plate Potential (EPP)

term for the excitatory postsynaptic potential in the Neuromuscular Junction EPP size is quantal multiple of MEPPs

Ocular dominance

term used to describe the preference a neuron has for one eye or another. Binocular neurons are found after layer 4 in the visual system.

the ___ has no brain segregation but the ___ does

thalamic; cortex

OFF bipolars have a different receptor

that leads them to be depolarized by release of transmitter from photoreceptors. These bipolars are therefore activated when the light is off and inhibited when the light is on.

Mediolateral map for motor neurons

that related to the proximal (near body axis) to distal (far from body axis)

Define "glial cell" and list the 3 main classes of glia?

the "supporting" cells they are proliferative (glial scars), inexcitable, and there are only a few (3) types

which synapse has a huge safety factor?

the NMJ (50-100 quanta released, when really only need 15)

Homeostasis

the ability of a system to maintain internal stability by making adjustments in response to changes in the environment

The amount of neurotransmitter released (the number of vesicles released) depends on

the amount of Ca2+ influx into the terminal, which depends on the degree of depolarization of the presynaptic terminal

Symptom of synaptic depressioN

the amount of transmitter released (m) in response to the second action potential will be lower than the first

Synaptic Cleft

the area in between pre- and post- neurons through which neurotransmitters diffuse through

What is a receptive field?

the area to which a cell is responsive / the area that would stimulate it EG center-surround cells

quantal content

the average number of quanta (vesicles) that are released after a single presynaptic action potential

Quantal content

the average number of quanta (vesicles) that are released after a single presynaptic action potential.

Quantal Size

the average size of the postsynaptic membrane depolarization (in mV) after a single quantal event (i.e. fusion of one vesicle with the presynaptic terminal cell membrane).

quantal size

the average size of the postsynaptic membrane depolarization after a single quantal event

What is the neuron's trigger zone and why does it have the lowest threshold?

the axon hillock / the initial segment the axon hillock has the highest density of voltage gated sodium channels and hence the lowest threshold

Phoneme

the basic sounds from which words are made. defined/distinguished by differences in frequency of formants (peaks in the harmonic spectrum of a complex sound)

signaling cascade example

the binding of calcium to calmodulin, which in turn activates protein kinases that phosphorylate proteins

which neurotransmitters in the brain operate almost exclusively through metabotropic receptors

the catecholamines and serotonin. The projection systems of these neurotransmitters are unusual because they arise from small groups of cells (nuclei) that project widely throughout the entire brain, and thus have widespread effects

soma

the cell body of a neuron which contains the nucleus and where most protein synthesis occurs and also where other organelles (specialized structures) also reside

Soma

the cell body of a neuron which contains the nucleus and where most protein synthesis occurs and also where other organelles (specialized structures) also reside. Cytosol - the protein rich liquid that fills the cell, also referred to as intracellular fluid (oppose to extracellular fluid, that surrounds the cell). Nucleus - double membrane bound organelle that contains the DNA and is the site of transcription (DNA to mRNA) within the cell. Ribosome - small organelle responsible for assembling protein from amino acids according to the mRNA sequence (code) in a process known as translation.

neuromuscular junction(NMJ)

the chemical synapse of a motor neuron axon muscle fiber.

Neuromuscular Junction (NMJ)

the chemical synapse of a motor neuron axon with a muscle fiber. Typically it is a large powerful synapse with multiple vesicles released per presynaptic action potential.

law of dynamic polarization

the concept that information arrives from incoming input (axon of neurons) and flows within neurons from dendrites, through the cell body to axon and to its axon terminal

law of dynamic polarization

the concept that information arrives from incoming input (axons of neurons) and flows within neurons from dendrites, through the cell body to the axon and to its axon terminals

Law of dynamic polarization

the concept that information arrives from incoming input (axons of neurons) and flows within neurons from dendrites, through the cell body to the axon and to its axon terminals.

neuron doctrine

the concept that the nervous system carries out its functions by passing information from once cell to the next. These cells are called neurons. Neurites of different neurons are NOT continuous and communicate by contact, not continuity.

Neuron Doctrine

the concept that the nervous system carries out its functions by passing information from one cell to the next. These cells are called neurons. Neurites (see below) of different neurons are not continuous and communicate by contact, not continuity.

Neuron doctrine

the concept that the nervous system carries out its functions by passing information from one cell to the next. These cells are called neurons. Neurites of different neurons are not continuous and communicate by contact, not continuity.

Primary visual cortex (V1)/Striate cortex

the cortical area that receives direct input from the LGN. The cortex is a layered structure and cells in layer 4 receive direct connections from the LGN. Layer 4 neurons typically make synapses onto layer 2/3 neurons, which make connections to layer 5/6 neurons and other locations in the brain

driving force

the difference between the membrane potential and the equilibrium potential for a specific ion species

What is meant by cortical lamination? How many layers are there?

the division of the cortex into distinct layer in the gray matter theres about 6-9 layers division of function as seen in the LGN but with an entirely different organization. Much of the Thalamic (LGN) input goes to layer 4

Driving Force

the difference between the membrane potential and the equilibrium potential for a specific ion species.

Benzodiazepines (tranquilizers), barbiturates, and some steroids increase

the effectiveness of GABA binding, increasing the proportion of time that the channel is in the open state in response to GABA binding

Resting Potential or Resting Membrane Potential

the electric potential difference across a cell's membrane at rest (not during an action potential). A typical neuronal resting potential is about -65 mV, meaning that the inside is more negative than the extracellular fluid.

Membrane Potential

the electric potential difference across a cell's membrane with respect to the outside extracellular fluid.

Memory

the encoded knowledge that is stored and sometimes later retrieved

Acetylcholine

the excitatory neurotransmitter at the neuromuscular junction (NMJ).

Entry of Ca2+ promotes

the fusion of synaptic vesicles with the presynaptic membrane

Nodes of Ranvier

the gaps in myelin. Many voltage-gated sodium channels are located within the nodes.

where are Muscarinic ACh receptors inhibitory

the heart

Where is the CNS representation of emotion located?

the hypothalamus - the cingulate, parahippocampal, and prefrontal cortexes are where the conscious sensation of emotion located the limbic cortical structures interact with the hypothalamus via the amygdala

Parallel processing

the idea that different stimulus attributes are process by the brain using distinct (parallel) pathways.

Hebb's Postulate

the idea that the timing of the pre and post synaptic firing of action potentials can alter the synaptic strength. Summarized as Neurons that fire together, wire together and Neurons out of synch, loose their link.

excitation

the injection of positive charges (usually carried by Na+)

Experiments with transgenic mice

the lickometer (mouse drank more out of umami than plain); also found that T1R2s are in different cells, but all T2R2s are in different cells --> all bitter substances taste the same

Photoreceptors

the light detectors rods and cones

Temporal summation

the long decay time course of an EPSP allows for multiple EPSPs at a single synapse to "piggyback" or summate over time.

temporal summation

the long decay time course of an EPSP allows for multiple EPSPs at a single synapse to "piggyback" or summate over time

Endocytosis

the material to be internalized is surrounded by an area of plasma membrane, which then buds off inside the cell to form a vesicle containing the ingested material.

what must happen for inactivated VGNaC to de-inactivate

the membrane must hyperpolarized

Equilibrium Potential or Nernst Potential

the membrane potential when forces caused by the concentration gradient of a particular ion and the cell's electrical gradient are equal and opposite. Determined by the Nernst Equation. At the equilibrium potential there is no net flow (current) for that ion.

Electrical signal

the nervous system uses electrical signals, that is transient changes in the electrical potential difference across neuronal membranes (membrane potential), to propagate information. Details of electrical signals will be covered in lectures 4-10.

What eventually becomes the PNS?

the neural crest, which is on the corder of the neural tube

What eventually becomes the CNS?

the neural tube (which is punched off from the neural groove which came from the neural plate)

Postsynaptic

the neuron that receives a signal from the presynaptic neuron. Known as the "downstream" neuron.

Presynaptic

the neuron that releases the neurotransmitter or sends a signal, usually caused by a presynaptic action potential. Known as the "upstream" neuron.

Nerve Growth Factor

the neurotrophic molecule for sympathetic neurons -- cell death held in check by trophic factors involved in programmed cell death stage

minis come from.....

the occasional release of NT in the absence of presynaptic stimulation. They reflect the probabilistic nature of NT release.

Lateral inhibition

the olfactory information leaving the olfactory bulb is shaped by lateral inhibition by local interneurons within the olfactory bulb. Periglomerular cells receive direct input from ORN axon and spread inhibition to nearby glomeruli.

Lateral inhibition

the olfactory information leaving the olfactory bulb is shaped by lateral inhibition by local interneurons within the olfactory bulb. Periglomerular cells receive direct input from ORN axon and spread inhibition to nearby glomeruli. Granule cells make dendro- dendritic connections with multiple dendrites of mitral cells. I

Membrane resistance (Rm)

the opposition of ionic flow across the membrane. The more channels in the membrane, the lower the membrane resistance. The lower the membrane resistance, the more the signal will attenuate over distance.

Membrane resistance

the opposition of ionic flow across the membrane. the more channels in the membrane, the lower the membrane resistance, the more the signal will attenuate.

Axial resistance (Ra)

the opposition of ionic flow down the axon or neurite. The greater the diameter of the neurite, the lower the axial resistance. The greater the axial resistance, the more the signal will attenuate over distance.

axial resistance

the opposition of ionic flow down the axon or neurite. the greater the diameter of the neurite, the lower the axial resistance.

Refractory Period

the period of time after an action potential when it is more difficult (i.e. needs more depolarization) to reach threshold. This period is dived into the absolute and relative segments. The absolute refractory period is when it is impossible to generate another action potential.

Positional information

the position of a cell determines the identity it will acquire a chemical morphogen released from one end of the axis forms a gradient, and the concentration of morphogen determines which genes are activated/expressed involved in regionalization

equilibrium potential/nernst potential

the potential needed to maintain zero net flow of a particular ion, when the chemical and electrical gradients are balanced

Nerve Terminal

the presynaptic part of a synapse innervates many postsynaptic cells

In facilitating synapses

the presynaptic terminal [Ca2+] following the action potential may not have been high enough to cause release of many of the docked vesicles. Thus, many vesicles are still available to be released in response to a subsequent action potential (n) Also, the [Ca2+] is higher than it was during the first action potential, meaning that the release probability (p) is increased compared to the first action potential.. Therefore, the amount of transmitter released (m) in response to the second action potential will be higher than the first. Facilitating synapses may contain fewer voltage-gated Ca2+ channels in the presynaptic terminal

What is M1? What does it innervate? How is it different from other motor areas in the cortex?

the primary motor cortex M1 primarily concerned with voluntary movements. It requires less stimulus to produce response than other areas

4 primary cortical sensory areas

the primary motor cortex, the somatosensory cortex the visual cortex and the auditory cortex

Consolidation

the process by which short-term memory becomes long-term memory

Learning

the process by which we acquire knowledge about the world

learning defined

the process by which we acquire knowledge about the world

Amyloid Precursor Protein (APP)

the protein from which the AB peptide (which forms Amyloid) is derived - it is cut by secretases to form AB AB peptide forms Amyloid forms Amyloid Plaques of Alzheimers

cytosol

the protein rich liquid that fills the cell, also referred to as intracellular fluid (opposed to extracellular fluid, that surrounds the cell)

Hierarchical processing

the receptive field properties get more complicated as the signal moves from photoreceptors to retinal ganglion cells

attenuation

the reduction in current magnitude due to distance and/or time

Attenuation

the reduction in current magnitude due to distance and/or time.

Facilitation

the second of two closely spaced epsps bigger than the first - the size of the EPP increases quantal number (m) increases but quantal size (amount of neurotransmitter per vesicle) does not change

What part of the neuron is its integration area?

the soma

What happens when inhibitory synapses are interposed between multiple excitatory synapses?

the soma can cause their EPSPs to attenuate to nothing before reaching the soma because it allows Cl- to rush in keeping the membrane potential at -65mV (its Equilibrium potential).

synapse

the space between the axon terminal of one cell and the dendrites of the next or between the cell(s) sending the signal (the presynaptic cell(s)) and the cell(s) receiving the signal (the postsynaptic cell(s)).

frequency coding

the strength of signal determined by frequency of the action potentials. a stronger signal increases the frequency of action potentials

ACh molecules bind to binding sites in the receptor causing

the subunits to rotate, leading to the opening of the ion channel, which is permeable to both Na+ and K+ ions. Negatively charged residues face the pore and serve to attract K+ and Na+ ions.

How does the opening and closing of synaptic channels plus the effect of leak channels relate to the shape of the synaptic potential?

the synaptic potential is the sum of current through receptors

What is one piece of evidence that neurons depend on their targets for survival signals?

the target affects survival (not production or differentiation) of neurons neuron number is proportional to target size

What is the trophic hypothesis for neuronal survival?

the target secretes a limited amount of a neurotrophic molecule needed for neuronal survival cell death is an active program held in check by trophic factors

Voluntary movements

the task and begin with an internal representation; Note: Brain represents the outcome of motor actions in a way that is independent of the specific muscles used or way the goal is achieved

Define critical period for sensory deprivation

the time in which the visual cortex is susceptible to sensory deprivation - overlap between the regions occupied by the thalamocortical axons drive by the two eyes

Scotopic vision

the vision of the eye under low light conditions. The term comes from Greek skotos meaning darkness and -opia meaning a condition of sight. (Rods active but light too dim to activate cones)

Photopic

the vision of the eye under well-lit conditions. In humans and many other animals, it allows color perception, mediated by cone cells, and a significantly higher visual acuity and temporal resolution than available with scotopic vision. (cones active and rods bleached or inactive)

what causes Vmem to return to Vrest after the undershoot?

the voltage gated K+ channels close, returning the permeability levels of K+ and Na+ and Cl- ions back to their original values.

Synaptic integration

the way in which multiple spatially or temporally distributed synaptic potentials sum

Synaptic Integration

the ways in which multiple spatially or temporally distributed synaptic potentials sum. Axon initial segment - also known as the "trigger zone". The axon initial segment has the highest density of voltage-gated Na+ channels and therefore the lowest threshold value.

place cell in mouse study

three place cells in hippocampus fire as the rat runs on a linear track. at the end, they fire in reverse (how to get home?). sequence replays at night

top down, programmed, bottom up

three possibilities for what decides specificity

affiliate with a past memory, create a story with sounds of unusual sounding syllables, synesthesia

three tricks to improve memory

attractive, permissive, repulsive

three types of axon guidance cues

Entry of Ca2+

through presynaptic voltage-gated Ca2+ channels causes neurotransmitter release Shows inward current due to Ca since other channels were blocked Involved intracellularly with signal cascades, Ca is more than a transporter

Absolute refractory period

time during which it is impossible to send another action potential. Inactivation gates of sodium channels lock. No sodium = no depolarization = no action potential. Helps direct action potential down the axon as only channels further downstream can open and let in depolarizing ions

Relative refractory period

time during which it is really hard to send an action potential. Occurs after absolute refractory period so the h gates are open, however, the cell is still hyperpolarized after sending an action potential. Thus, it would take even more positive ions than usual to reach depolarization potential.

Glutamate receptors that are ionotropic receptors (e.g., AMPA-R) are also permeable

to both Na+ and K+

When glutamate binds to this receptor, a channel opens that is permeable

to both Na+ and K+ ions

In the brain, metabotropic receptors work

together with ionotropic receptors

prosody

tone, pitch, rhythm, tempo

rostral

towards the face

Bipolar cells

transmit signals (directly or indirectly) from the photoreceptors to the ganglion cells between photoreceptors and ganglion cells

axon

transmit signals over a distance

axon terminal

transmit signals to other neuron dendrites or tissues

Axon initial segment

trigger zone. highest density of voltage-gated Na+ channels and therefore the lowest threshold value

T or F: If there is a postsynaptic alteration (i.e. receptors are more or less active), EPP amplitude will change

true

T or F: If there is a postsynaptic alteration (i.e. receptors are more or less active), mEPP will change

true

T or F: If there is a presynaptic alteration, EPP amplitude will change

true

T or F: microglia provide immune surveillance for the nervous system

true

T or F: the physiological role of ionotropic receptors is determined by their ion conductivity

true (anion selective --> inhibitory, cation selective --> excitatory)`

T or F: kinesin is a motor protein that transports vesicles along the axon.

true!

Programmed Cell Death

twice as many cells are born than needed..

how many binding sites does AChR have?

two

default mode network and salience network

two brain networks in super agers

Sensory neuron

type of afferent neuron (a cell that carries sensory information toward the brain from the periphery).

Motor neuron

type of efferent neuron (a cell that carries information away from the brain to the periphery) that synapses onto skeletal muscle fibers.

astrocyte

type of glial cell in the central nervous system (CNS) which aids in maintaining the appropriate chemical environment of the brain including formation of the blood brain barrier and removing chemicals from the extracellular fluid surround synapses

astrocyte

type of glial cell located in the central nervous system (CNS) which aids in maintaining the appropriate chemical environment of the brain including formation of the blood brain barrier and removing chemicals from the extracellular fluid surround synapses

Astrocyte

type of glial cell located in the central nervous system (CNS) which aids in maintaining the appropriate chemical environment of the brain including formation of the blood brain barrier and removing chemicals from the extracellular fluid surround synapses.

oligodendrocyte

type of glial cell responsible for myelinating axons within CNS. A single oligodendrocyte wraps part of its membrane many times around segments of multiple axons

Oligodendrocytes

type of glial cell responsible for myelinating axons within the CNS

Oligodendrocyte

type of glial cell responsible for myelinating axons within the CNS. A single oligodendrocyte wraps part of its membrane many times around segments of multiple axons.

Schwann cell

type of glial cell responsible for myelinating axons within the PNS.

Schwann cell

type of glial cell responsible for myelinating axons within the peripheral nervous system (PNS) . A single Schwann cell wraps itself many times around a single segment of one axon.

Schwann cell

type of glial cell responsible for myelinating axons within the peripheral nervous system (PNS). A single Schwann cell wraps itself many times around a single segment of one axon

microglia

type of glial cell that has many immune response properties including removal of cellular debris, modulating local inflammation and influencing neuronal survival

Microglia

type of glial cell that has many immune response properties including removal of cellular debris, modulating local inflammation and influencing neuronal survival.

microglia

type of glial cell that has many immune response properties including removal of cellular debris, modulating local inflammation, and influencing neuronal survival

denndrite

type of neurite, branched and shorter than the axon, that receives much of the synaptic input to that nneuron

dendrite

type of neurite, usually branched and shorter than the axon, that receives much of the synaptic input to that neuron

Dendrite

type of neurite, usually branched and shorter than the axon, that receives much of the synaptic input to that neuron.

Rod cell

type of photoreceptor with very high sensitivity to light, but has very low spatial resolution and does not contribute to color vision. Rod cells are specialized for night vision and saturate in daylight.

Cone cell

type of photoreceptor with very high spatial resolution, sensitivity to color and motion. It is relatively less sensitive to light than the rod cells and works best in daylight

Acetylcholine receptor (AChR)

type of synaptic receptor at the NMJ, located on the muscle. NMJ AChR are ligand-gated ion channels that desensitize and are activated by nicotine so sometimes referred to as a nicotinic AChR or nAChR. This channel, when opened, permits the flow of Na+ and K+ currents.

mechanical and chemical

types of cues

What is hemispatial neglect?

unawareness of the existence of left space including left body parts due to lesions in the right hemisphere as if one half of the universe ceases to exist in any meaningful form

Hypothalamus

unconscious drives autonomic command center the master regulator receives and integrates sensory info from the exterior and interior worlds and coordinates a 3-part response

tetanus

uncontrollable muscle spasms

declarative and procedural memory

use different neural pathways and structures

Nernst Equation

used to calculate the equilibrium potential for a single ion species .

Goldman-Hodgkin-Katz (GHK) equation

used to calculate the membrane potential if a cell is permeable to multiple ions

What is the flexor reflex?

used to quickly respond to and avoid noxious stimuli Whenever you have a flexor reflex you have a crossed extensor reflex as well -- when one leg pulls away/flexes the other stiffens/extends to prevent you from falling over

With reference to feeding - How does the brain sense body reserves of energy over the long term? What does it want to know?

uses Leptin to measure fat reserves - the long term energy source - to adjust metabolism and maintain stable weight, want anabolic to equal catabolism fat levels change over long periods so leptin is important for long term regulation of feeding and metabolism

what was initial evidence for the neuron doctrine?

using the golgi stain (the black reaction) to show the existence of synapses (gaps) between neurons

Tau protein

usually it stabilizes microtubules. They are abundant in neurons of the central nervous system and are less common elsewhere, but are also expressed at very low levels in CNS astrocytes and oligodendrocytes. Pathologies and dementias of the nervous system such as Alzheimer's disease and Parkinson's disease are associated with tau proteins that have become defective and no longer stabilize microtubules properly.

What was the Spemann/Mangold organizer experiment and why was it important?

usually part of the mesoderm gives rise to the notochord beneath the neural tube. when they transplanted a 2nd organizer into the embryo it induces a second body axis including the neural tube provides evidence for concept of Induction

role of emotion in humans

valence for memories, allows episodic to have meaning, will we do it again

orexogenic peptides from the hypothalamus/pituitary stimulate

ventral hypothalamic neurons that coordinate foraging activities

language areas in 3 month old

very similar areas light up: left hemisphere

Dorsal stream

visual processing pathway from primary visual cortex to the parietal cortex. It is responsible for analyzing motion and depth. The "where" stream.

Ventral stream

visual processing pathway from primary visual cortex to the temporal cortex. It is responsible for analyzing form and color. The "what" stream.

Photoreceptor

visual sensory cell that converts light into electrical signals. Located at the innermost layer of the retina next to the pigment epithelium.

How the Retina works

vitamin A is a component. and when the pigment rhodopsin was exposed to light, it yielded the protein opsin..... thus vitamin A was essential in retinal function.

calcium hypothesis

voltage dependent calcium entry couples stimulation (AP) to secretion. Vesicles released is proportional to Ca2+ to the fourth power

increased permeability due to _______

voltage gated ion channels

tetrodotoxin

voltage gated sodium channel antagonist

Tetrodotoxin (TTX)

voltage gated sodium channel antagonist. Toxin found in some puffer fish that eliminates action potentials. Conduction - the movement or traveling of an action potential along the axon. Action potentials that begin at one end propagate in one direction.

Define driving force. How do driving force and conductance relate to the current that passes through ion channels? Be able to use the ohm law relationship

voltage is the electrical driving force for an ion - the difference between he membrane potential and that ions equilibrium potential ionic current = ion's conductance × ion's driving force I = g × V

Explain the ways in which an axon's passive properties: membrane resistance, membrane capacitance, and internal resistance attenuate a voltage change with distance away from the site where an action potential is peaking

voltage largest at site of Na+ entry and gradually weakens over time due to passive leak channels and the membrane capacitance passive properties like a leaky hose - rising water pressure = voltage bulge-ability = increased capacitance leaks = conductances

somatic nervous system: voluntary or involuntary?

voluntary

Somatic PNS

voluntary motor system direct, no relay neuron needed Ventral horn -> motor axon-> muscle

hypocretin

wakefulness

What is an in vitro stripe assay? What kind of info does it provide?

way to test the growth of cells on a substrate made of cell membranes in alternating stripes from the posterior and anterior poles (of the tectum) provides info/studies binary growth decisions of cells and axons towards surface-bound molecules in vitro

Describe the James-Lange Theory

we experience emotion in response to physiological changes in our body e.g. we feel sad because we cry

James-Lange theory of emotion

we experience emotion in response to physiological changes in our body. physical changes are the emotion

Intensities

we sense relative, not absolute light intensities

Eion tells you

what Vm is needed to make an ion's fixed concentration gradient in equilibrium

Is a taste determined by what receptor a chemical activates or what cell it activates?

what cell it activates

European plan

what you become depends on who your parents are (think the Queen)

Equilibrium

when a system has stabilized and all competing forces are balanced.

Steady State

when a system is stabilized and concentrations remain constant, but forces may or may not be in equilibrium, some action (in neurons ATP driven Na/K pump) may be needed to remain at steady state.

steady state

when a system is stabilized and concentrations remain constant, but forces may or may not be in equilibrium, some action may be needed to remain inn steady state.

how does voltage gated Na channel work?

when cell is depolarized to threshold, voltage sensor domain (S4) twists away fro the inside, causes channel to open which is 12x more permeable to Na than K

cat study for what's necessary for emotion

when cerebral cortex was removed, cats got mad. when he removed the hypothalamus, no rage.

define steady state

when concentrations are equal and a system is stabilized but certain forces are not equal..certain amount of energy requires

Heterosynaptic plasticity

when synaptic strength between two neurons maybe be regulated by a third neuron/synapses

Hyperpolarization

when the membrane potential of a neuron become more negative.

Depolarization

when the membrane potential of a neuron becomes more positive (or less negative).

In the context of action potentials, what is the significance of threshold

when they reach threshold, local potentials trigger action potentials -- threshold is the level of depolarization needed for the propagation of an action potential

end plates

where synapses occur that deal with release of ACh at neuromuscular junction

sperry

who did the frog rotation eye exteriment

American plan

who you become depends on your surroundings

Neurons that fire together

wire together

lisencephaly

wrong layers cells arrest near ventricle; migration

Is NMDA permeable to Ca++

yes

are EPPs graded?

yes

are IPSPs graded?

yes

are electrical synapses bidirectional?

yes

are minis graded?

yes

are receptor potentials graded?

yes

are synaptic potentials graded?

yes

do AChR desensitize?

yes

do AMPA desensitize

yes

T or F: inhibition opens channels

yes (and this, in turn, increases conductance, which makes for a lower membrane resistance)

does axon diameter affect axial resistance?

yes (inc caliber dec axial resistance)

does axon diameter affect membrane resistance?

yes (inc caliber decreases membrane resistance)

does axon diameter affect capacitance?

yes (inc caliber inc capacitance)

Can specific memories be lost and others retained? What is the evidence?

yes -- high degree of locality for some memories

cable properties: just passive yes or no

yes!

do EPSPs obey cable properties?

yes! amplitudes decrease along length of dendrite

if a membrane of a cell is permeable to all ions, is there a point where net ion flow across the membrane stops?

yes. the permeabilities used in the GHK at rest (K:Na:Cl = 1:0.025:0.4) would be maintained. But since -65 is not the equilibrium potential for any of the ions, K+ would flow out and Na+ would flow in. After a time, the concentrations of these ions would eventually balance out and eventually the concentration of K inside would equal the concentration of K outside (same for Na) thus the ratio of the concentrations would be 1, and the equilibrium potential for each would also be 1. Cl- might resist this for a short time, but even in typical situations, there is not a Cl- pump, so those ions would diffuse as well and dissipate any concentration gradient. If the concentration of all ions is equal on both sides of the membrane, the membrane potential will be zero.

Without calcium

you cant release neurotransmitter

action potential propagation goal is to propagate as far as possible without opening VGIC kinda

yup (why myelination helps-- separating distance so that the negative charges can't line up on membrane and "take" incoming + charge, instead the + charge must go down, be "felt" be rest of axon)

at GHK net flow =

zero

what is net current @ an ion's nernst potential

zero

What kinds of "tricks" allow impressive feats of memory?

• Affiliate memories with a sequence already in memory

role of ligand gated channel (neurotransmitter receptors) is determined by ion conductivity

cation selective: excitatory AChRs: Na+ & K+ AMPA(glutamate receptors): Na+ & K+ NMDA (glutamate receptors): Ca++ mostly EPSP - excitatory post synaptic potential anion selective: inhibitory GABA & Glycine receptors: CI- IPSP - inhibitory post-synaptic potential

differentiation

causes dynamic polarization, dendrites

Voltage gated Na+ Channels

causes gNa to go up/down single, long polypeptide - 4 domains, with 6 transmembrane α helixes each. Voltage sensor is S4 more permeable to Na+ than K+ has a voltage sensor that twists away from the inside when the cell is depolarized. This twist causes the channel to open and allows an inrush of Na+ to depolarize the neuron further

Elevating external [K+] (which makes the K+ equilibrium potential more positive)

causes the reversal potential to shift to a more positive potential

Superthreshold

causing an action potential in the postsynaptic neuron; occurs when the synapses is located close to the initial segment (highest density of Na+ channels thus lowest threshold)

Soma

cell body which contains the nucleus and where most protein synthesis occurs

Apoptosis

cell suicide programmed cell death

What part of the brain divides the motor cortex from the sensory cortex?

central sulcus

components of nervous system in conscious perception of emotion

cerebral cortex: cingulate/frontal lobes, amygdala

Miniature end plate potential (mini or MEPP)

change in membrane potential of a muscle fiber after a vesicle in the presynaptic terminal spontaneously fuses with the presynaptic cell membrane.

End plate potential (EPP)

change in membrane potential of a muscle fiber as a result of a presynaptic action potential which evokes the release of vesicles at the neuromuscular junction.

end plate potential (EPP)

change in membrane potential, depolarization of the postsynaptic muscle fiber, caused by an action potential in the presynaptic motor neuron. Usually large enough to bring the membrane potential of the muscle cell well above the threshold for producing a postsynaptic action potential. This postsynaptic action potential triggered by the EPP causes the muscle fiber to contract. Evokes the release of vesicles at neuromuscular junction.

Presynaptic inhibition

change in quantal number (# of vesicles released)

ocular dominance segregation.

changes in developmental phenomenon in which unequal ocular dominance columns (odcs) in layer IV occur after monocular deprivation.

Synaptic modulation

changes in strength or efficacy of neuronal connections. Can be caused by a variety of physiologic and signaling mechanisms at time scales that vary from ms to days or longer.

voltage-gated ion channel

channel whose conductance (ability to pass ions) is dependent on membrane voltage. Both voltage-gated K+ channels and Na+ channels need to be depolarized from the resting potential to open

AP: channelopathies or myasthenia gravis? AChR: channelopathies or myasthenia gravis?

channelopathies; myasthenia gravis

Ion Selective Channels

channels through the membrane, composed of proteins, that allow ions to pass through. Selectivity determined by pore size and charge. Many types including gated and those active at "rest" or "leak channels".

what's cool about the NMJ:

chemical specificity (high density of AChR) spatial specificity: closely aligned with synaptic terminal

recognition molecules

chemical tags that allowed them to recognize appropriate target regions

dopamine hypothesis evidence

chlorpromazine and other dopamine antagonists reduce psychotic symptoms. better the affinity, lower dosage needed, hallucinogens increase dopamine. MRI: increased dopamine release in patients, dopamine increases correlated with disease severity

The receptive fields in the LGN are....

circular (center-surround) & monocular (one eye or the other)

Why has Aplysia been useful for studies of synaptic plasticity?

classical conditioning techniques altered the behavior - seemed to make memory Habituation and Sensitization

Voltage gated channels

closed during resting state. They open and close based on voltage difference across the cell membrane. Three states: 1. Deactivated (closed) - at rest 2. Activated(open)- when a current passes through and changes voltage difference across a membrane, channel will activate 3. Inactivated (closed) -as neuron depolarizes, Na h gate shuts and blocks sodium ions from entering.

if the concentration gradient is reduced, then the equilibrium potential becomes....

closer to 0 mV

What effects does light have on the membrane potential of and transmitter release from photoreceptors

closes a cation channel (Na+, Ca++) and hyper polarizes the cell so transmitter only released in the dark

What properties make a cell a neuron?

compartmentalization of structure and function (receptive regions, integration, and output -- dendrites, soma, and axon) Electrical excitability synaptic connections Neurons convey information to/from other neurons. they are more variable than other cell types Most are non-replicating post biotic

Alpha-bugarotoxin

competitive agonist for nAChRs that are purified from snake venom, binds and blocks the receptor

What 2 gradients are in balance when an ion is said to be at tis equilibrium potential?

concentration gradient and electrical gradient are equal and opposite

equilibrium (in general) is reached when......

concentrations no longer change (+ and - charges are balanced so that the final net charge is zero in both containers and therefore the membrane potential, which is a measure of difference in the net charges between inside and out = 0 mv)

equilibrium is reached when....

concentrations no longer change (they might not be equal) and the cell's concentration and electrical gradients are equal and opposite

like ACh, Dopamine, norepinepherine, and serotonin are categorized by second

confinement to a small number of neurons in specific cells groups in the brain. Dopaminergic neurons, for example, are located almost entirely in the substantial nigra and VTA while norepinepherinergic neurons are located in the locus coeruleus. Thus, a small number of neurons project widely and diffusely throughout the brain. As we shall see these, these neurotransmitters have many important roles, and are the targets of many neurological disorders as well as being the targets of a wide variety of drugs.

electrical synapse

connection between two cells through gap junctions that allows the direct passage of electrical current (ions). Allows for fast and bidirectional transfer of electrical information between cells

How do ocular dominance columns form?

considerable overlap between the regions occupied by the thalamocortical axons drive by the two eyes during critical period. over time the neurons and space dedicated to one eye or the other is pruned due to use/experience forming segregated ODCs

brainstem

consists of medulla and pons and is in charge of respiration, circulation, posture, maintenance, and vital functions

potential treatment for ptsd

consolidation and reconsoldiation both require protein synthesis, preventing synthesis of new proteins during tests of recall decreases subsequent recall

Outer segment of a photoreceptor

contains membranous disks with light- sensitive photopigments, the inner segment contains the nucleus and the synaptic terminal releases glutamate onto bipolar and horizontal cells. Photoreceptors are depolarized in the dark

Central Pattern Generators

crossed-extensor reflex in which one side extends the other side flexes seems to provide a common building block for locomotion...walking is the subconscious alternation of arms and legs swinging

What is a decussation?

crossing in the optic chaism so that the L visual field from both eyes projects to the R cortical hemisphere and the R field to the L hemisphere. The nasal part of the retina crosses to contralateral side, the temporal part remains on the ipsilateral side

What evidence suggests that the human nervous system is special?

culture, smart, language -- very slow development, more plasticity?

midsagittal view

cut in half side view

coronal view

cut in half top view

Eye rotation experiemtn

cut the optic nerve and rotated the eye 180 in the socket so what was up was now down and what was anterior was now posterior; once the severed axons regrew, the frog saw the world upside down and did not adapt.

impact of myelin

found in Schwann cells. Makes escape from the membrane impossible and so preserves action potential. Decreases capacitance. Normally, negative ions spread to axon edges to get away from eachother. This attracts outside positive ions to the membrane. Myelin provides thick layer so that fewer negative ions gather as they are farther away from positive charge. This means as action potential rushes by, it is easier to depolarize as there are fewer negative ions. Decreases membrane permeability to ions so that fewer ions cross the member during an action potential. Therefore, fewer ions need to recross the membrane after the action potential through the sodium potassium pump that is going to pumping back out all the Na+ ions that came in through the voltage-gated sodium channels and pumping back in all the K+ ions that left during the action potential. This processes uses energy and so myelination increases efficiency in terms of energy needed to maintain these ion concentrations after action potential.

Categorical perception

frequencies of formants are continuous but we categorize them to identify phones because ewer are most sensitive to differences at the category boundary (which are language specific)

GABA channels are considered inhibitory because: a) they block voltage gated sodium channels b) the channel is selective to potassium and Ek is hyperpolarized compared to both threshold and the resting potential c) the channel is selective to chloride and ECl is very hyperpolarized compared to both threshold and the resting potential d) the channel is selective to chloride and ECl- is hyperpolarized compared to threshold, thus it keeps neuronal potential near the resting potential

d) the channel is selective to chloride and ECl- is hyperpolarized compared to threshold, thus it keeps neuronal potential near the resting potential

conduction aphasia

damage to arcuate fasciculus, fluent word production, preserved comprehension, impaired repetition

Long-term memory

days to decades

Long-term memory (LTM) lasts

days to decades

place and grid cells

deal with positional memory

medial temporal lobe

declarative/explicit memories

botulinum toxin cleaves SNARE proteins. How will the toxin effect (increase/decrease/no change) EPP amplitude

decrease (each AP will cause fewer vesicles to be released, decreasing total amplitude

blockers _______ chloride conductance while agonists _______ chloride conductance

decrease; increase

Short-term depression

decreased synaptic strength (EPSP amplitude) apparent after two or more pre-synaptic action potentials. Caused by depletion of vesicles from the presynaptic terminal.

botulinum toxin cleaves SNARE proteins. How will the toxin effect (increase/decrease/no change) quantal content

decreases (disrupted SNARE protein will cause fewer vesicles to be released)

Concurrent inhibition

decreases the membrane resistance allows the falling phase to return to the resting potential more quickly (via Cl- entry) so summation is less likely to occur

inhibition happens by ____

decreasing membrane resistance and the EPSP magnitude.

What is the difference between a delusion and a hallucination?

delusion - a super odd belief (e.g. of influence or grandeur) hallucination - a perception/experience thats totally false and odd

multiple sclerosis is a ____ disease that ______ conduction velocity

demyelinating; slows

may have spines (axons/dendrites/both/none)

dendrites

Off bipolar cell

dendrites contains excitatory AMAP type glutamate receptors. Since photoreceptors release more glutamate in the dark, "off" cells also release more NT in the dark.

On bipolar cell

dendrites contains inhibitory mGluR6 type glutamate receptors. Since photoreceptors release less glutamate in the light, "on" cells then release more NT in the light since they are inhibited less.

List 3 input regions on a neuron

dendrites, soma, and axon hillock

glucose release from axon varicosities onto ______

dendritic spines

two areas of brain where neurogenesis continues into adulthood?

dentate gyrus (in the hippocampus); olfactory bulb

How does positive feedback play a role in the rising phase of an action potential?

depolarization causes the conductance of Na+ to go up which in turn causes more depolarization its a regenerative loop

General EPP

depolarization of the membrane due to increase in Na+ and K+ permeability caused by ACh binding to receptors.

What kinds of stimuli initiate action potentials?

depolarizing stimuli

cable properties

describe the passive flow of current (not taking into account voltage-gated channels). Passive signals become reduced (attenuated) over distance.

Cable properties

describe the passive flow of current (not taking into account voltage-gated channels). Passive signals become reduced (attenuated) over distance. The loss of current is due to Membrane resistance (Rm), Axial resistance (Ra), Membrane capacitance (Cm), Diameter.

Saltatory conduction

describes the propagation of an action potential along a myelinated axon from one node to the next.

Simple cell

descriptive term for a neuron in V1 with a receptive field shaped not like the simple center/surround found in the retina (and LGN) but rather an elongated field - with a specific orientation

Position Emission Tomography (PET)

detects gamma rays emitted by a radioisotope on a tagged molecule. Localizes molecules to which the tracer binds (e.g. amyloid) or traces blood flow sites from which signals arise are reconstructed to give a 3D map

positron emission tomography (PET)

detects gamma rays emitted by a radioisotope on a tagged molecule. localizes molecules to which the tracer binds (amyloid) or traces blood flow

specific language impairments

developmental disorders that selectively affect language processing. not related to impaired intelligence, poor environment or hearing

pseudowords vs real words in neuroimaging

different hot spots of activity

synaptic organizing molecules

differentiation

What is chemotropism?

diffusible attraction cues for growth cones

anterograde

directional grade, meaning toward the axon terminnal

anterograde

directional term, meaning toward the AXON TERMINAL

retrograde

directional term, meaning toward the CELL BODY

Anterograde

directional term, meaning toward the axon terminal.

retrograde

directional term, meaning toward the cell body

Retrograde

directional term, meaning toward the cell body.

Diseases of affect

diseases of emotion

Aphasia

disorder of speech arising from brain damage

multiple postsynaptic neurons innervated by the same presynaptic cell is an example of axonal _______

divergence

How are inhibitory ligand-gated channels regulated?

diversity of chemicals. blockers decrease GABA or glycine's ability to increase g_CI. Agonists enhance chloride conductance in response to GABA

what does it mean to be a promiscuous cation channel (like AChR!)

doesn't care which positive ions flow through it

if we know about dopamine in schizophrenia, why no cure?

dopamine doesn't explain all symptoms, other neurotransmitters involved, side effects, not great for negative symptoms (don't treat disease)

flexors are dorsal or ventral?

dorsal

nucleus

double membrane bound organelle that contains the DNA and is the site of transcription (DNA to mRNA) within the cell

If conductance is equal

driving force determines if their is an outward or inward current

Agonist

drug that can mimic receptor

Why might there be sequential firing of place cells in the hippocampus, not only during, but also after an animal has run on a track?

during - to remember way that it came after - to get back to where it went

hypothesis for zebra finch song learning

during the sensory phase, the bird forms and internal representation of the song: template. During the motor phase he practices, matching his song to template until he gets it right

notochord causes ____ to fold and form the neural ___

ectoderm; tube

graded potential

electric signal that channges the membrane potential inn a continuous manner

-80mV is K+ ideal _________ _________-

electrical gradient

the ______ ______ is the membrane potential

electrical gradient

Action potential

electrical impulses that send signals around your body

K+/Na+ channel is:

electrogenic

What did Luigi Galvani discover?

electrophysiologist made a frogs leg twitch - animate the dead with electricity? led to mary shelley - think frankenstein

Radial Glial Cell

elongated cells that form guiding tracks radiate tangentially from subcortical areas and principal neurons migrate radially from ventricular zone along these radial glia involved in migration

what types of memories are encoded best

emotional

emotional lateralization

emotional expression in right hemisphere: starts in left face then spreads

Describe the Cannon-Bard theory

emotional feeling can occur independently of emotional expression because lack of reliable correlation between emotional experience and state of the body - e.g. fear cause higher heart rate, but so does anger and the flu

cannon-bard theory of emotion

emotional feeling can occur independently of emotional expression, lack of reliable correlation between experience of emotion and physiological state of the body

Canon-Bard Theory

emotional feeling can occur independently of emotional expression.

Emotion is laterlized

emotions start in the left face as emotional expression begins in the right hemisphere

List 4 aspects of the visual world that are encoded in the visual system (and one that is not)

encode Shape, Color, Position, and Movement dont encode Light Intensity

memory

encoded knowledge that is stored and later retrieved

Memory:

encoded knowledge that is stored and sometimes later retrieved.

Schwann cells ____ growth of neurons

encourage

Posterior parietal area

essential for the planning of purposive movements (eg brushing teeth)

Shunting inhibition

even though the reversal potential (ECl) for inhibitory synapses is approximately the resting membrane potential, the opening of GABA channels is very effective in preventing the postsynaptic neuron from reaching threshold. This inhibition essentially allows Cl- entry anytime the membrane potential is depolarized. This shunts the excitatory synaptic current.

episodic memory

events

Anterograde amnesia

events after a trauma

Retrograde amnesia

events prior to trauma

Tau hypothesis

excessive or abnormal phosphorylation of tau results in the transformation of normal adult tau into PHF-tau (paired helical filament) and NFTs (neurofibrillary tangles). Tau protein is a highly soluble microtubule-associated protein (MAP)

Bipolar cell

excitatory neuron in the retina that transmits information from the photoreceptors to the retinal ganglion cells and amacrine cells. Bipolar cells do not fire action potentials, but have a graded release of neurotransmitter.

Declarative memory

explicit; available to consciousness and can be expressed in language; episodic (events) and semantic (facts)

james-lange emotion theory

expression precedes exp.

Hubel and Wiesal

extended Kuffler's retinal ganglion cell receptive field mapping first to LGN and then to V1

hypertrophy of hippocampus

extensive spatial memory

semantic memory

facts

A neurologist tests the stretch reflex on both knees of a patient and finds: Both reflexes are abnormally weak (hypo-reflexic). Name a problem that could lead to this symptom.

failure of one or more of the components (muscle, muscle spindle, motor or sensory axon)

Rather, their actions are to bias the neuron, by causing either a

fairly long-lasting depolarization, thereby making the postsynaptic cell more likely to fire action potentials, or by causing a fairly long-lasting hyperpolarization, thereby making the cell less likely to generate

permeability of K increases in which phase of the action potential?

falling phase

T or F: If there is a postsynaptic alteration (i.e. receptors are more or less active), quantal content will change

false

T or F: If there is a presynaptic alteration, mEPP amplitude will change

false

True or false: each specific neuron type can be identified by expression of a single gene

false

T or F: electrical synapses are unidirectional

false (bidirectional!)

T or F: myelin is produced by Schwann cells in the CNS.

false (by Schwann cells in the PNS, or by oligodendrocytes in the CNS)

T or F: a reflex is a voluntary movement

false (involuntary)

T or F: protein synthesis primarily occurs on the rough ER in the soma and axons

false (soma and DENDRITES, not axons)

distance and graded potential relationship?

farther from trigger zone, more likely to attenuate before reaching

cell adhesion molecules CAMs use ___ to fasten together ____

fasciculation; axons

AMPA: fast or slow rise and decay

fast rise and decay

What are the advantages of electrical synapses compared to chemical ones?

faster tamper proof energy efficient synchronous

inhibition results in a faster/slower fall and a higher/lower rise

faster;lower

Retinal Ganglion Cells

feature detectors receives visual information from photoreceptors

Define affect

feeling or emotion, especially as manifested by facial express or body language

Retinal ganglion cells

fire action potentials in response to light and these impulses propagate along the optic nerve to the rest of the brain. Serve as a source of output from the retina and are the only retinal neurons that fire action potentials

hippocampal place cells

fire an action potential when they enter a particular area

the most rostral lobe of the cerebral cortex

frontal lobe

cerebrum lobes

frontal lobe (front), temporal lobe (middle under), parietal lobe (middle top), occipital lobe (back)

chemical synapse

functional connection between two cells where information can be transferred between them without being physically connected

Chemical Synapse

functional connection between two cells where information can be transferred between them without being physically connected. At chemical synapses an action potential in the presynaptic cell (see below) triggers the release of neurotransmitter molecules which bind to receptors on the postsynaptic cell.

Charge (Q)

fundamental quantity of electricity and a property of matter. A charge may be positive or negative. Like charges repel while opposite charges attract. An electron has an elementary charge of -1 and a proton has a charge of +1.

why are mental illnesses hard to study

fuzzy boundaries, distinction between ill/odd changes, no medical tests, hard to test in animals

Step 0 in development

gastrulation

Voltage

gated Calcium channel - calcium channels clustered near the active zone of a presynaptic terminal that are voltage gated and open when the presynaptic terminal is depolarized by an action potential.

Voltage

gated ion channel - channel whose conductance (ability to pass ions) is dependent on membrane voltage. Both voltage-gated K+ channels and Na+ channels need to be depolarized from the resting potential to open.

Ligand

gated ion channel - type of neurotransmitter receptor in the postsynaptic membrane, also known as inotropic receptor, where the binding of a neurotransmitter molecule, causes the opening of an channel and allows ions to flow through the channel.

How are genes expressed in the nervous system?

genes synthesize gene products (DNA -> Transcription -> mRNA -> Translation -> Protein)

short term food?

gherlin; distention of stomach, carb levels, CCK, insulin, gastric distension

endoderm

gives rise to gastrointestinal tract, organs

neural tube

gives rise to the CNS

neural crest gives rise to

gives rise to the PNS

neural plate gives rise to what?

gives rise to the neural groove which gives rise to the neura tube

What is fluorescence?

glows the visible or invisible radiation emitted by certain substances as a result of incident radiation of a shorter wavelength such as X-rays or ultraviolet light the property of absorbing light of short wavelength and emitting light of longer wavelength.

Major excitatory neurotransmitter

glutamate

excitatory amino acid NT

glutamate

excitatory NTs we talked about

glutamate, acetylcholine

NMDA receptor

glutamate-gated ion channel, that is also voltage dependent. Mg2+ blocks the receptor useless depolarization pushed the Mg2+ out of the pore. Typical AMPA receptors do not desensitize, are permeable to Na+ and K+ and Ca2+. Has slower rise and decay times than AMPA receptors.

AMPA receptor

glutamate-gated ion channel. Typical AMPA receptors desensitize, are permeable to Na+ and K+ but impermeable to Ca2+. Has fast rise and decay times

AMPA receptor

glutamate-gated ion channel. Typical AMPA receptors desensitize, are permeable to Na+ and K+ but impermeable to Ca2+. Has fast rise and decay times.

what excitatory NT is released in the CNS? what kind of postsynaptic receptors are there?

glutamate; AMPA/NMDA

NMDA receptor

glutamte-gated ion channel that is also voltage dependent. Mg2+ blocks the receptor useless depolarization pushed the Mg2+ out of the pore. Typical AMPA receptors do not desensitize, are permeable to Na+, K+ and Ca2+. Has slower rise and decay times than AMPA receptors

List 2 results related to imprinting discovered by Konrad Lorenz in his studies of goslings

goslings imprinted on first moving object no matter what it is the effect is particularly strong only the first day or two of postnatal life

Define imprinting

goslings trust/follow first moving object they see

receptor potential

graded potential in the dendrites of a sensory neuron in response to a stimulus.

Ephrin A

gradient high in posterior tectum & low anterior

Ephrin A

gradient that is high in posterior and low in anterior

Glia (glial cells)

group of several different types of non-neuronal cells in the nervous system, each of which is specialized for particular functions

glia(glial cells)

group of several different types of non-neuronal cells in the nervous system, each of which is specialized for particular functions

Glia (glial cells)

group of several different types of non-neuronal cells in the nervous system, each of which is specialized for particular functions.

axon guidance

growth cones sense cues in environment

7 universal emotions

happiness, sadness, contempt, surprise, fear, disgust, anger

evidence for critical period

hard to learn second language when older, recovery from damage is better in children, children raised w/o hearing speech might not learn later

Metabotropic receptor-mediated response

has GDP bound when there's no neurotransmitter bound to receptor.. Activated G protein beta gama sub unit. has a Leakage K channel that's always open ... teir Responses can be amplified

Why might a taxi driver have an abnormally large part of the hippocampus?

has to remember a ton of routes -- spatial memory generally in the hippocampus

Describe the Downer experiment that argues that the amygdala is important in emotion

he experimented with monkeys, removing the amygdalae - found that animals behavior depended on which eye was used to view the world - when the monkey used the eye on the side with an amygdala it was aggressive and afraid of humans. When it used the eye on the side without the amygdala it was tame

gradients

help to explain the expansion and compression of maps

What is meant by "shunting" when talking about synaptic inhibition?

helps neuron stay close to resting potential when other neurotransmitters are trying to depolarize it, inhibitory Inhibition mechanism -- Cl- influx that counterbalances Na+ influx of excitatory synapses

What is a clinical use of inhaled oxytocin?

helps with Aspergers Syndrome - promote social engagement

What does unilateral eye patching during postnatal development do to the ocular dominance histogram?

histogram shifted in late line in favor of the unmatched eye. Vision from the deprived eye is permanently amblyopic

Golgi stain

histological method that stains the entire neuron including any neuronal processes (dendrites and axons). The Golgi method labels only a small fraction of the population of cells within the sample

Golgi stain

histological method that stains the entire neuron including any neuronal processes (dendrites and axons). The Golgi method labels only a small fraction of the population of cells within the sample.

Nissl stain

histological method that stains the nucleus and surrounding material within a neuron. Nissl bodies refers to the rough ER staining, which is prominent in long axon neurons

Nissl stain

histological method that stains the nucleus and surrounding material within a neuron. Nissl bodies refers to the rough ER staining, which is prominent in long axon neurons.

What are homonymous and heteronymous connections?

homonymous - connections with the muscle from which a the signal arises from eg. a stretch receptors axon makes many of its connections with motor neurons that innervate the muscle from which it arises heteronymous - connections with other muscles that perform similar functions

Waggle dance

honeybees do it to communicate food location

inside out birth order (layer 1 outermost)

how interneurons migrate

Retinopy

how the 2D surface of the retina is mapped onto surfaces of subsequent structures (thalamus + cortex) reason why L + R visual field seamlessly knit together despite being in very different parts of the brain

what does GHK allow us to calculate

how to calculate membrane potential if multiple ions are permeable

Neurotransmitters

how we communicate between one cell and the next. Excitatory neurotransmitters cause the signal to propagate - more action potentials are triggered. Inhibitory signals work to cancel the signal.

Why is the phospholipid bilayer impermeable to ions?

hydrophobic tails don't want to come in contact with ions

Huntington's is associated with hyper/hypokinetic

hyper

Parkinson's is associated with hyper/hypokinetic

hypo

What is the extent of genetic relatedness between identical twins? Fraternal twins?

identical twins 100% fraternal twins 50% same as any other siblings

evidence of genetics of schizophrenia

identical twins more likely to have it, closer relatives more likely, adopted biological family more likely

relationship between ion fluxes and postsynaptic potential changes

if membrane potential of muscle fiber kept at E_k then EPC will arise from influx of Na+ because there is no driving force on K+. Without a voltage clamp to prevent postsynaptic membrane potential changes, this Na+ influx would cause a large depolarization and yield a large depolarizing EPP. At usual resting membrane potential of -90 mV, there is a small driving force onn K+ but a greater one on Na+. Therefore, more Na+ flows in than K+ out. The influx of cations cause an EPC smaller than that at -100 mV and hields a depolarizing EPP that is also smaller. At the reversal potential of 0mV, Na+ influx and K+ efflux are balanced and so no net current flow, yielding neither an EPC nor an EPP. At potentials more positive than Erev the balance reverses with no influx of Na+ and a large efflux of K+. This produces an outward EPC and hyperpolarizing EPP. Polarity and magnitide of the EPC depend on the electrochemical driving force on permeant ions which determine the polarity and magnitude of the EPP. EPs will depolarize when the membrane is more negative than Erev and hyperpolarize when membrane is more positive than Erev.

Ca concentratid out side of cell

if that is altered and the driving force is taken away then there's little AP

Reciprocal inibition

if you activate biceps, you have to prevent triceps from activating at the same time

Any molecule can taste good or bad

if you put anything in a sweet cell, the animal will like it

latty hypothalamus

if you remove, makes you fatty. so it controls repression of appetite. hence its stimulated by leptin

default mode network

implicated in memory encoding, storage, and retrieval, including a larger hippocampus

Procedural memory

implicit; non-declarative and not easily describable by language. Skills and learned reactions that are retrieved unconsciously (eg. how to type)

medial temporal lobe

important for declarative but not procedural memory consolidation

Synaptic Vesicle

in chemical synapses -- holds neurotransmitter to later secrete into synaptic cleft

What is the extracellular matrix and what glycoprotein in the matrix permits axons to grow?

in permissive substances the axon advances along a substrate - usually the extracellular matrix. the glycoprotein Laminin integrins on axons bind to laminin

What is Reactive Attachment Disorder and how might it relate to synaptic rearrangement/critical periods?

in the absence of a normal mother in childhood the behavior was adversely affected could be due to poor rewiring, immature neural circuits that formed under the wrong influences

Where does the conditioned fear response occur? Provide a synaptic mechanism that could associate a sound with fear

in the amygdala - long term potentiation NMDA glutamate receptors open a Ca++ channel only when the postsynaptic membrane is already depolarized (i.e. by the pain input) So originally only weak inputs that are synchronously active with the pain input allow Ca++ entry into the dendrite Later when Ca++ entry causes new AMPA glutamate receptors to insert into the postsynaptic sits, potentiating the formally weak NMDA receptor synapses Hebbs postulate

Monocular (and location)

in this instance, monocular refers to neurons that are only responsive to one eye (either R or L). Neurons in the retina, LGN, and layer 4 of V1 are all monocular.

laminin

in vivo permissive substrate, glycoprotein

List 3 key features of autism

inability to form emotional bonds impairments in communication skills repetitive and stereotyped behaviors

what happens if myelin is degraded

muscle weakness and numbness. Nerves aren't sending information the right way, signals are either diminished or destroyed.

mesoderm

muscles

Mesoderm

muscles, bones

spatial learning

must be related to medial temporal lobe and hippocampus

rhombencephalon

myelencephalon and metaencephalon (later hindbrain)

Neurons can receive synaptic input on all of the following areas except ___________

myelinated axon segments

the only step that continues from before birth into adulthood is

myelination

growth cone

navigator at the tip of the axon

How many axons in the corpus callosum

nearly 200 million across the two hemispheres

What is the difference between a modulatory synapse and a metabotropic synapse?

nearly all modulatory synapses are metabotropic, but not all metabotropic synapses are modulatory modulator released from a neuron that activates its receptor (GPCR) and forms a second messenger that changes the sensitivity of the iontropic rector to transmitter released from another nerve terminal metabotropic synapses indirect and slow and change metabolism

How does early experience affect levels of oxytocin or vasopressin or their receptors in humans or experimental animals?

neglected children - lower vasopressin/oxytocin levels in pampered rats - higher levels of oxytocin

Define the Law of Dynamic Polarization

nerve cells are polarized, receiving information on their cell bodies and dendrites and conducting info to distant locations through axons

Where are AChRs localized on muscle fibers?

nerve terminal membrane

electrical signal

nervous system uses electrical signals, that is transient changes in the electrical potential difference across neuronal membrane (membrane potential), to propagate information

neural fold-->____CNS/PNS

neural crest; PNS

neural plate-->_______-->neural tube; CNS/PNS

neural groove; CNS (plate groove tube)

hippocampus and olfactory bulb

neurogenesis continues at low levels in adult

Draw a graph of a neurons membrane potential (y) as a function of changing extracellular potassium concentration (x)

neuron membrane potential also affected by Cl- and Na+ so not a linear relationship curve upwards - like exponential starting a little after x= 1 and around y = -82

(Lower) Motor neuron

neuron who's cell body is in the gray matter of the spinal cord and send its axon out of the spinal cord to innervate individual muscle fibers.

Tuning

neuronal tuning is the idea that neurons can - respond dynamically (usually firing rate) to different stimuli. If a neuron is tuned to a particular aspect of a stimulus, that neuron will have a greater response to the preferred stimulus and weaker or no response to non-preferred stimuli.

Wallerian Degeneration

neurons die when cut off from the soma

Depth perception

neurons in V1 (cat) that selectively respond to lateral disparity in R and L visual fields

Hebb's postulate

neurons that "fire together wire together", neurons that "fire out of synch, lose their link"

Hebian synaptic mechanism

neurons that fire together strengthen each other

What is Hebb's postulate?

neurons that fire together wire together

vesicle hypothesis

neurotransmitter in membrane-bound spheres

what is the quantal hypothesis

neurotransmitter is released in multi-molecular packets. The EPSP is made of many mini EPPs (quanta) released simultaneously

What is the quantal hypothesis of neurotransmission and what is a key piece of evidence that supports it?

neurotransmitter is released in multimolecular packets each of approximately the same size

The fusion of vesicles causes

neurotransmitter molecules to be emptied out into the synaptic cleft

ACh

neurotransmitter that acts mostly at neuromuscular junction of striated muscles.

nerve growth factor

neurotrophic molecule needed for neuron survial

What are channelopathies?

new congenital diseases associated with mutant ion selective channel genes. Includes certain neurological conditions with seizures and migraines

neurulation, regionalization, neurogenesis, migration, differentiation, programmed cell death, axon guidance, synapse formation, synaptic rearrangement

nine steps of neuron development

can electrical junctions do inhibition?

no

do GABA channels desensitize?

no

do NMDA desensitize

no

does myelination affect Raxial

no

does the density of leak channels affect C membrane?

no

is AMPA permeable to Ca++

no

Does each muscle have its own nerve from the spinal cord?

no - lots of muscles are all innervated by the same branched nerve (lots of targets, lots of exit ramps from the highway)

anterior RGC axons

no avoidance or preference of tectum membranes

botulinum toxin cleaves SNARE proteins. How will the toxin effect (increase/decrease/no change) NTs per vesicle

no change

botulinum toxin cleaves SNARE proteins. How will the toxin effect (increase/decrease/no change) presynaptic action potential duration

no change (SNARE are not involved in the action potential)

botulinum toxin cleaves SNARE proteins. How will the toxin effect (increase/decrease/no change) mEPP amplitude

no change (a single vesicle will release the same amount of NT, and that will open the same number of channels

botulinum toxin cleaves SNARE proteins. How will the toxin effect (increase/decrease/no change) reversal potential of the AChR

no change (only presynaptic machinery will be affected)

agenesis

no corpus callosum; axon guidance

What does bilateral eye patching during development do to the ocular dominance histogram?

no effect on the histogram but profound effects on vision

holoprosencephaly

no lobes (whole)/1 ventricle; regionalization

if the membrane is permeable to all ions, over time is there a concentration gradient?

no!

if the membrane is permeable to both anions and cations, is there an electrical gradient?

no!

are there genes unique to individual cell types?

no, there's the belief that maybe there is a combinatorial code where a combination of genes is what determines the cell type

is sodium ion diffusing down the membrane during an action potential?

no; it's the charge that is being "felt"/propagated down

Along the axon, it is the name for the unmyelinated space between two consecutive myelinated portions.

node of ranvier

contains DNA (axons/dendrites/both/none)

none

There are reuptake mechanisms for

norepinephrine, dopamine, serotonin, glutamate, GABA, and glycine

At the time the visual cortex is susceptible to sensory deprivation it is

not fully formed

do IPSPs change the voltage

not necessariy

In most synapses in the brain, a single action potential is

not sufficient enough to bring the postsynaptic neuron to firing threshold

Lateral geniculate nucleus (LGN)

nucleus in the thalamus that receives visual input from retinal ganglion cell axon and sends output to the primary visual cortex. The LGN as a whole receives visual information from both eyes, but individual layers and individual neurons receive synaptic connections from just one eye.

how to classify neurons

number of "neurites", shape, connections or function, axon length, neurotransmitter (usually 1 per neuron), named cells

In what ways can neurons be categorized?

number of neurites shape/dendrites connections/functions axon length neurotransmitter some are specifically named

ventromedial hypothlamic syndrome

ob(v)ese

pain reflex

flexor

Why are the rostral-caudal/dorsal-ventral coordinates different for the forebrain and the brain stem?

flexure appears in the longitudinal axis during development

current

flow or movement of electric charge

Current (I)

flow or movement of electric charge. Units = Amperes, amps (A)

neural plate fate

folds into neural groove, walls of which (akak neural folds) move together and fuse to form neural tube, and the adjacent neural crest

Types of neurotransmitter receptors

for FAST synaptic transmission, ionotropic receptors are needed such as: nAChR (acetlycholine) AMPA-R (glutamate) GABA-A (GABA)

Write the Nernst Potential Equation.

for a single ion! Membrane Potential = (RT) / (ZF) × ( log{ [out] / [in] })

List 3 general sites where axonal guidance cues originate

for chemical cues -- Substrate (e.g. laminin is ligand for interns on axons) Other axons (axons bundle together because of CAMs) target as beacon for mechanical cues e.g. glial tubes used to guide peripheral regenerating axons

evidence for james-lange theory

forced smiling can make you feel better, inability to smile causes depression, cues go straight to expression.

anterograde amnesia

forget events after trauma

retrograde amnesia

forget events prior to trauma

Cranial nerves

form the connections in the brain

anorectic peptides from the hypothalamus/pituitary do what to metabolism?

increase it

How do small-scale changes happen?

increase synaptic efficacy or size or formation of new dendritic spines

What kinds of fMRI findings have been seen in serious depression?

increased blood flow in some brain regions associated with it ( EG area 25)

Facilitation

increased synaptic strength (EPSP amplitude) apparent after two or more presynaptic action potentials. Caused by elevation of residual Ca2+ in the presynaptic terminal.

How does myelin affect cable properties and conduction velocity?

increases conduction velocity lowers membrane capacitance - like duct taping a hose to decrease bulge ability raises membrane resistance -- like plugging the leaks in a hose

why is a thicker axon advantageous for squid

increases conduction velocity. makes synapses to the muscles of a squid's mantle. can contract mantle and flee more easily

How does inhaling or injecting oxytocin affect social behavior?

increases peoples level of true in each other, as well as their ability to judge what other people are feeling may help treat autism

a stronger signal does what to action potentials

increases the frequency of them

lannon-bard emotion theory

independent

Entorhinal cortex "grid" cells

individual neurons fire at regular spatial intervals as an animal walks in its enclosure. Cortex innervates hippocampus. Each cell has a different hexagonal receptive field- somehow grid cells give rise to place cells- not yet clear how

entorhinal cortex grid cells

individual neurons fire at regular spatial intervals, cortex innervates hippocampus, gives rise to placecells

oligodendrocytes ___ growth of neurons

inhibit

components of myelin

inhibit axon growth.

What are the advantages of chemical synapses compared to electrical ones?

inhibition multiple channels allow specificity modulated plasticity amplify multiple time scales - fast v slow resilient

what are two advantages of chemical synapses compared to electrical ones?

inhibition multiple channels: can have different NTs acting on same cell and doing different things modulation: can be different sizes, different amounts NT released resilient specificity of effects plasticity can work over multiple time scales amplify

Concurrent Inhibition during temporal summation

inhibition concurrent with excitatory synapses can prevent temporal summation as inhibition not only the decreases EPSP amplitude, but also reduces membrane resistance which shortens the decay time course of the EPSP.

concurrent inhibition during temporal summation

inhibition concurrent with excitatory synapses can prevent temporal summation as inhibition not only the decreases EPSP amplitude, but also reduces the membrane resistance which shortens the decay time course of the EPSP

interneurons are often

inhibitory

Horizontal cell

inhibitory neuron in the retina whose actions influence the signals that are transmitted from the photoreceptors to the bipolar cells.

Amacrine cell

inhibitory neuron whose actions influence the signals that are transmitted from the bipolar cells to the retinal ganglion cells.

Glycine

inhibitory neurotransmitter found in the spinal cord. Glycine receptors are neurotransmitter-gated CI channels

Glycine

inhibitory neurotransmitter found in the spinal cord. Like GABA receptors, glycine receptors are neurotransmitter-gated Cl- channels.

Basal ganglia

initiation and execution of movement

Describe experimental manipulations that can cause a prairie vole to act more like a meadow vole or vice versa

injecting vasopressin makes male prairie voles more like meadow voles injecting oxytocin in female prairie voles makes them more like meadow voles

language

innate and learned, also conveys info

communication

innate, conveys info

extrafusal muscle fibers

innervated by alpha motor neurons to produce contraction of a muscle

Enteric ANS

innervates gut

in glial cells [K]____ = 100mM

inside

lidocane blocks pore from the _____

inside

the inactivation loop/protein of the VGNaC is on the (inside/outside) of the cell

inside

recollection

instead of long term memory for recent events

Compare and contrast memory and instinct

instincts are memories without experience kind of like memories from experience of a species over eons rather than over a lifetime

Nerve cells

integrate and delay information from other neurons in a neural circuit

Horizontal Cells

integrate and regulate the input from multiple photoreceptor cells cell bodies in the inner nuclear layer

Transgenic mice

integrate the transgene into the DNA of mice (ex. GFP)

What is the SNARE hypothesis of neurotransmission?

interactions between SNARE proteins on the vesicle and on the presynaptic membrane, modulated by calcium, lead to vesicle fusion vesicle fusion is catalyzed by interaction of vesicle-associated SNARE proteins with other SNARE proteins (target SNARES) on the membrane with which fusion will occur

Meylin

intermittent wrappings around an axon formed by glia (oligodendrocytes in the CNS and Schwaan cells in the PNS). The additional layers of membrane (high in lipid content) act as an insulator (decreases Cm) and increases the distance along the axon a signal can travel passively (increases Rm).

if we are measuring something's membrane potential, how do we do it?

intracellular microelectrode compares inside cell to growund. Hollow glass pipette with tip open filled with a high K+ salt solution connected to a voltmeter

Human facial expressions

involuntarily activated by emotions

autonomic nervous system: voluntary or involuntary?

involuntary

Amacrine cells

involved in processing interneurons in the retina

What is an ion? a cation? an anion?

ion = atom that is charged, its what moves around neurons -- ionic current is the net charge movement mainly across membranes cation = positive anion = negative

Reversal potential of the end plate current changes when

ion gradients change

What are ion selective channels? Briefly describe what they do and how come they are selective.

ion selective channels = protein channels with pores that ions can pass through, a lot of variety with different ion selectivities. Selective because generally anion channels lined with cations and visa versa

In neurobiology, what does "conductance" mean?

ion sort of equivalent to the permeability term for an ion in the GHK equation Resistance = 1/conductance R = 1/g

List 3 ways electricity in the nervous system differs from electricity in wires

ions vs electrons ions and ionic current across membranes vs. electrons and current along wires no analog for membrane potential in wires

nAChR's agonist

is Nicotine

Pyramidal smile

is a volitional smile (M1 motor cortex --> lateral tracts); the fake smile

Headless chicken

is an example of the Central Pattern Generator

Facilitation

is due to enhanced [Ca2+] in the presynaptic terminal after the first stimulus and It iis blocked by injection of the Ca2+ buffer EGTA into the presynaptic terminal

piggybacking of EPSP

is enabled because epsp's have fast rise, slow fall

Main current flowing through channels of AMPA receptor at rest

is going to be Na sodium, not potassium, because sodium has a larger driving force.

At resting membrane potential the largest driving force

is going to be on Ca

Ephrin-A gradient

is high in posterior tectum & low anterior (Ephrin-A binds to a "receptor" on retinal ganglion cell axons called EphA, a receptor tyrosine kinase- that is high in posterior and low in anterior retinal ganglion cells) Gradients seen in retina and tectum Many gradients of different molecules (too many!) Locks and Keys? No! Means that the preference is grated and there gives extraordinary flexibility

Medial temporal lobe

is important for declarative but not procedural memory consolidation

The CPG

is in the spinal cord. The CPGs are activated by tonic descending activity from brainstem

Neural crest's fate

is to become the peripheral nervous system

If a synapse is established on a dendrite, how does the caliber of that dendrite affect its amplitude and shape in the soma?

it affects the amount of attenuation -- the fatter the dendrite, the less attenuation because it has a lower internal resistance.

how does language differ from other forms of communication

it can encode new ideas into signals, learned. only humans

When we say neural connections are specific, what do we mean?

it is not a random network of synaptically connected neurons there are separate streams with specific, functional connections

Why is the motor system so complicated?

it requires the coordinated actions of muscles in a changing, unpredictable environment we know more about the outputs than we do about the initiation of movement

why does a presynaptic action potential cause a postsynaptic EPP

it synchronizes the release of many transmitter quanta

how does a change in permeability affect membrane potential?

it will be dominated by the equilibrium potential of the ion with the high permeability

Why is -10 mV excitatory?

it's above threshold

Why is the Sodium Potassium Pump essential for all neurons?

its electrogenic - sends 3Na+ out for every 2K+ in. So it maintains the concentration gradient (more K+ out and less Na+ in) and keeps the inside of the neuron negative which allows for neural signaling to work right

equilibrium for an ion is reached when....

its particular concentration gradient and electrical gradient are equal and opposite

What is the meaning of a concentration gradient across a membrane? How do ions behave in such a gradient?

its the net charge difference (voltage) across the membrane. Ions diffuse down their concentration gradients

why is the fall of the EPSP slow

just K_ leak channels

myotatic stretch reflex

knee-jer response. Stimulating the stretch receptors in the quad muscles initiates a receptor potential which then triggers an action potential in the sensory neuron. the action potential travels up the axon to the spinal cord where the sensory neuron makes a synapse with a motor neuron, causing an action potential in the motor neuron axon. the action potential in the motor neuron travels down the leg to the synapse onto a muscle fiber and triggers a muscle contraction and behavioral response (leg extension)

myotatic reflex

knee-jerk/monosynaptic

amyloid plaques

known to be aggregates of a peptide called "AB" (dense aggregates of protein located outside of neurons)

How and why does axon caliber affect conduction velocity?

large axon caliber = decreased axial resistance = increased conduction velocity small axon caliber = increased axial resistance = decreased conduction velocity

Neuropeptides

large classification of neurotransmitter molecules that are made up of a short polypeptide chain. Neuropeptides active GPCRs for diverse effects on varying timescales.

How are facial muscles of expression controlled?

large number of face muscles that can be moved both voluntarily or can be involuntarily activated by emotion pyramidal (fake) smile looks different from emotional smile

Impact of axon diameter

larger diameter = higher conduction velocity = faster signal. Less resistance in ion flow, more space to travel, less likely they will run into something to bounce them back

mesencephalon

later midbrain

anorectic peptides from the hypothalamus/pituitary stimulate

lateral hypothalamic neurons to coordinate inhibition of feeding centers

the theory that describes the flow of information through the nervous system: information arrives on the dendrites, travels through the neuron/axon and is passed along

law of dynamic polarization

Why is memory important for human behavior?

learning and the motivation to do things

where is wernicke's area

left superior surface of temporal lobe between auditory cortex and angular gyrus

brain of zebra finch while learning clue

lesions of LMAN in young birds prevent learning, but lesions in adult don't affect singing

How does Area LMAN help the songbird learn its song?

lesions to the LMAN in young birds add noise to the system, allowing the bird to test many variations and finally ge the rights song. Otherwise the song would crystallize in the wrong format

due to the cable properties of dendrites, the thicker (larger caliber) the dendrite, the ______ attenuation occurs

less

The concordance rate for schizophrenia is ~50% for monozygotic (identical) twins and ~20% for dizygotic (fraternal) twins. What does this tell you about genetic and environmental causes?

less chance with more genetic variance but must also consider gene-environment interaction and susceptibility vs causal genes

Ionotropic Receptor

let ions flow AMPA Receptor & NMDA Receptor

AChRs are _____ gated

ligand

ionotropic receptors

ligand - gated ion channels. cause graded potentials when activated which effects nearby membrane that is brief and local. allow certain ions to pass. Nearby excited when Ca and Na, or not when K+ or CI. metabotropic - activate second messengers inside the neurons. they can affect the behavior of ion channels or change behavior of proteins or etc.

Laminin

ligand for integrins on axons

Ionotropic receptors are

ligand-gated ion channels (LGICs)... meaning When neurotransmitter binds to the receptor, it causes the receptor to directly open an ion channel

brain parts for the conscious feeling of emotion

limbic system, medial temporal lobes, prefrontal, cingulate, parahipopcampal

Nasal epithelium

lining of the nasal passage that contains the olfactory sensory neuron cell bodies and cilia. Coated with mucosa

Induction

local interactions guide subdivisions Parts of the germ layers induce growth Ectoderm is not destined to be a brain, but the mesoderm's influence that makes is become a brain.

first depolarization is _____ and caused by....

local; positive ions coming in from another source (e.g. stretch receptor, synapses)

A neurologist tests the stretch reflex on both knees of a patient and finds: The reflex is abnormally weak in one knee but normal in the other (asymmetric). Name a problem that could lead to this symptom.

localization indicates location of the lesion/injury symmetry would suggest metabolic/systemic problem

Ventral horn of the spinal cord

location in the gray matter of the spinal cord that contains the cell bodies of the lower motor neurons.

Amygdala

location of fear

leptin is long or short term?

long

axon

long neurite that extends from the soma. 1 axon that originates from cell body and rest branches

axon

long neurite that extends from the soma. Although an axon often branches extensively, a neuron usually has only 1 axon that originates from the cell body

Axon

long neurite that extends from the soma. Although an axon often branches extensively, a neuron usually has only 1 axon that originates from the cell body. Axon initial segment - site of action potential initiation, close to the origin of the axon. Axon terminal - specialized endings of the axon that makes synaptic contacts with other cells (often with dendrites/spines)

Neurons out of synch

loose their link.

calcium in transmitter secretion

lowering the concentration of Ca2+ outside a presynaptic motor nerve terminal reduces the size of the EPP. EPP gets smaller because lowering Ca2+ concentration decreases number of vesicles that fuse with the plasma membrane of the terminal.

______ reflect the probabilistic nature of neurotransmitter release

mEPPs

end plate current (EPC)

macroscopic current resulting from ions flowing through ionotropic receptors in the end plate

Phospholipid bilayer

major component of the cell's membrane with 2 layers of "water loving" hydrophilic heads and "water fearing" hydrophobic tails, arranged so the tails point towards each other. As the tails are non-polar they form a barrier to water soluble ions and even water itself.

GABA

major inhibitory neurotransmitter in the central nervous system.

Glutamate

major neurotransmitter at excitatory synapses in the central nervous system.

One motor axon will...

make a synapse with many muscles fibers.

false memories

make memories make more sense, morph with each recall

GABA receptor modulators

make the receptor more or less responsive to GABA without themselves being the agent for opening or closing the channel

Miniature End Plate Potential (mini or MEPP)

make up an epp (the quanta) vesicles

What is the motor cortex homunculus? Why does it look so weird?

map of the functions of motor cortex as a person with enlarged features. looks weird with huge face, hands, tongue because it represents the devotion of the brain/neurons to those parts

What kind of connections might generate an oriented receptive field in primary visual cortex?

maybe convergence of several center surround cells that form a line is the basis of orientation specificity -- implies that the receptive field properties get more complex by combining simpler receptive fields

Anterograde amnesia

means you cant remember events after a trauma

Functional Magnetic Resonance Imaging (fMRI)

measures blood flow in brain which is proportional to local neural activity for language modalities - allowed identification of the different areas that were active when people spoke different parts of language

fMRI

measures blood flow in brain, which is proportional to local neural activity

proximal muscles are medial or lateral?

medial

Olfactory receptor

member of a family of G-protein coupled receptors that is activated by odorants. There are many different genes for olfactory receptors (~1400 in rodents, ~800 in humans). Each type of olfactory receptor is activated by a subset of odorants. Some receptor only respond to a couple of identified odorants (narrowly tuned), others are activated by more odorants (broadly tuned).

Vesicle

membrane bound organelle that contains neurotransmitter molecules in the presynaptic terminal.

diffusion associated with an ion selective channel can give rise to ......

membrane potential

graph of cell membrane potential as a function of changing extracellular potassium concentration vs. glial cell

membrane potential vs log extracellular K (straight line glial cell with slope of +60mV/10 fold change), neuron a little different because has Na and Cl to consider

Reversal potential (VRev)

membrane potential where the net current through an open ligand- gated ion channel (or receptor) would be zero. Depends on the permeability of the channel to different ions and the equilibrium potential for those ions. For example the reversal potential at the NMJ is ~ 10 mV.

reversal potential

membrane potential where the net current through an open ligand-gated ion channel (or receptor) would be zero. Depends on the permeability of the channel to different ions/equilibrium potential for those ions.

Sodium Potassium pump

membrane protein that uses ATP to transport ions across the membrane against their concentration gradients. pumps 3 Na+ from inside to outside, then pumps 2 K+ into the cell. Reason that Na+ has a higher concentration outside the cell and K+ has a higher concentration inside the cell. Selective permeability combined with concentration gradients established by the pump create the resting negative membrane potential

What is false memory? Is it a bad thing or a good thing?

memories morph with each recall and may fill in or confabulate data for memories reconsolidation idea

Instincts

memories without experience

Instincts:

memories without experience

Hippocampus

memory

Define memory and define learning

memory - the encoded knowledge that is stored and later retrieved learning - the process by which we acquire knowledge

Nearly all modulatory synapses are....

metabotropic

Reuptake

method of removing neurotransmitter from the synaptic cleft through transporters in presynaptic terminal

Reuptake

method of removing neurotransmitter from the synaptic cleft through transporters located the presynaptic terminal.

Astrocytes

most numerous type of glia form the blood-brain barrier support the CNS secrete neurotropic factors take up K+ neurotransmitters

What is meant by "Henneman's size principle"?

motor neurons generate muscle force by sequential recruitment to fire action potentials - beginning with the smallest/weakest and ending with the strongest/largest allows for fine motor control

Henneman's Size Principle

motor neurons generate muscle force by sequential recruitment to fire action potentials, beginning with the smallest/weakest and ending with the largest/strongest needed to accomplish the motor action Ex) when you pick something up and you don't know how heavy it is, you initially activate the weakest motor unit, and if that is not efficient then you activate the second motor unit which is stronger, until you can actually pick it up

programmed cell death

motor neurons generated in two fold excess

Henneman's Size Principle

motor neurons that have smaller motor unit sizes, which usually have smaller axon diameters, fire before neurons with larger motor unit sizes. Enables the incremental control of the magnitude of an individual muscle's contraction in response to varying inputs received by its motor pool.

conduction

movement or traveling of an action potential along the axon. Action potentials that begin at one end propagate in one direction

Cortical Lamination

much of the thalamic input goes into layer 4...

Non-linear synaptic summation

multiple EPSPs will not linearly summate (i.e. the final amplitude is less than the sum of individual amplitudes) because the synaptic potential cannot exceed the reversal potential and gets progressively smaller the closer the membrane potential gets to the reversal potential.

non-linear synaptic summation

multiple EPSPs will not linearly summate because the synaptic potential cannot exceed the reversal potential and gets progressively smaller the closer the membrane potential gets to the reversal potential

synapse formation

multistep process involving acquisition of many pre/post synaptic features and their perfect apposition

Cerebellum

muscle and reflex coordination can store motor sequences/actions

cerebellum

muscle and reflex coordination; movement control center

succinyl choline is a......

muscle relaxant: not cleaved easily by ACh esterase.... chills in the sysnapse, too much neurotransmitter, desensitization and then paralysis!

Homonymous

muscle spindle stimulates this muscle to contract. (ie the quad) (1E-6)

cilia-->Olf R cell-->olf nerve -->glomerulus-->___

olf tract

Integrins

on axons bind to laminin

integrin

on axons that binds to laminin

Second messenger

one of the intracellular signaling molecules that is activated by an extracellular signal (i.e. activation of GPCR) and triggers a signaling cascade to alter a neuron's excitability or physiology.

What is the crossed extensor reflex?

one side extends while the other flexes Central Pattern Generators Building block for locomotion

A motor unit consists of

one somatic efferent (motor) neuron and all of the muscle fibers (cells) that it innervates.

Binocular

only responsive stimulation of either eye. A neuron might be more tuned to either R or L, and respond weakly to stimulation of the non-tuned eye, or a neuron might respond to both eyes equally.

semantic memory

only type of memory before age 2

HM

patient who could not consolidate declarative memory 1) Medial temporal lobe is important for declarative but not procedural memory consolidation 2) Procedural memory formation can go on perfectly well without any conscious awareness 3) Spatial learning must be related to medial temporal love and hippocampus

components of nervous system in physical expression of emotion

peripheral autonomic, endocrine, motor systems, amygdala, hypothalamus, brainstem

what does reversal potential depend on

permeability of channel to different ions equilibrium potential of those ions

a _________ ion is one that is freely diffusible across the membrane

permeant

Growth Cues 3 types

permissive; attractive; repulsive

Falling Phase

phase of action potential after the peak (Vmax) when the membrane potential hyperpolarizes and falls to or below the resting potential (Vrest).

What is a lipid bilayer composed of and how are these molecules arranged? why in the absence of channels is it so impermeable to ions?

phospholipids hydrophilic heads and hydrophobic core because of their charge and the nature of the phospholipid bilayer, ions cant cross without facilitated diffusion/active transport and need channels

Each activated kinase can

phosphorylate many ion channels

instincts

phylogenetic memories based on the experience of a species over eons

Instincts are what

phylogenetic memories which are based on the experience of a species over eons rather than over a lifetime but can be remarkably similar

phylogeny of emotion

phylogentically old. probably all vertebrates get mad. parts of human brain that are phylogentically old. communication

two main components of emotion

physical expression--emotional state, and conscious perception--sensation/feeling

Charles Sherrington

pioneering English neurophysiologist who first studied reflexes

posterior parietal important for

planning

what is the selectivity of an ion selective channel determined by

pore size and charge

Spemann/Mangold organizer experiment

portion of the mesoderm called "the organizer" normally gives rise to the notochord... they transplanted a second organizer into an embryo. It INDUCED a second body axis,... double headed frogs

morphogen gradient

positional information, determines which genes are activated

Regionalization

positional information; morphogens

retinotectal map

posterior retinal axons project to anterior tectum and vice versa

Molecular basis of chemoaffinity

posterior retinal ganglion cell axons preferentially grew on membranes of anterior tectum and avoided posterior tectum membranes

if the perturbation affects quantal size, the effect is likely to be (presynaptic/postsynaptic)

postsynaptic

Heterosynaptic facilitation

pre and post synaptic facilitation EG - Excitatory transmitter released and GPCR activated, cyclic AMP formed, leading to inactivation of potassium channels that terminate the AP. Nerve terminal stays depolarized longer, calcium channels remain open longer, more calcium enters and more neurotransmitter is released.

posterior RGC axons

preferentially grow on membranes of anterior tectum and avoid those of posterior tectum

most complex movements associated with the

premotor cortex

reverse myotatic

presents muscle tears (inhibitory)

superagers

preserved neuroatomical integrity and better memory in two brain networks

if a perturbation affects quantal content, the effect is likely to be(presynaptic/postsynaptic)

presynaptic

Robo

prevents axons that cross the midline from being attracted by netrin to cross again

Myotatic stretch reflex

prevents falling; when muscle is stretched afferent makes monosynaptic connections on motor neurons going to same muscle -> activates motor neuron that contracts quadriceps -> counteracts the bend of the knee

What is the reverse myotatic reflex?

prevents tears (1) muscle contracts, stretching Golgi Tendon Organ (2) If force on muscle excessive, a neuron from Golgi tendon organ fires, the motor neuron is inhibited, and the muscle relaxes

Reverse myotatic reflex

prevents tears. The lb afferents from golgi tendon organs contact inhibitory interneurons that decrease the activity of α motor neurons innervating the same muscle.

Reverse myotatic reflex

prevents tears; sensory ending near tendon sends a DRGC axon into the spinal cord -> innervates inhibitory interneuron -> inhibits motor neuron to muscle

Cranial nerves → gustatory nucleus →

primary gustatory cortex (nervous goo knuckles primarily)

striatum

procedural/implicit memories/non-declarative

Neurulationn

process by which in very early embryo some cells get set aside to become the nervous system. Refers to the folding process in vertebrate embryos, which includes the transformation of the neural plate into the neural tube. Ectoderm is not destined to be a brain, but the mesoderm's influence that makes is become a brain

Exocytosis

process by which the contents of a vesicle are released to the exterior through fusion of the vesicle membrane with the plasma membrane.

learning

process by which we acquire knowledge about the world

What does memory consolidation mean?

process to make long term memories

Pituitary Glands

produces critical hormones, which are chemical substances that control various bodily functions.

Pineal Gland

produces melatonin, which helps maintain circadian rhythm and regulate reproductive hormones.

Alzheimer's disease

progressive dementia, gradual degeneration characterized by Amyloid Plaques and Tangles

neurogenesis

progressive restriction of cell fate

Inactivation

property of some depolarization-gated ion channels whose conductance goes to zero even though the membrane depolarized. Voltage-gated sodium channels inactivate shortly after opening. The membrane must hyperpolarize for the channels to de-inactivate and return to their closed conformation before they can open again.

Desensitization

property of some ligand-gated ion channels such that if they are open for a long time, they will desensitize or close even though neurotransmitter molecules may still be bound to the receptor.

Desensitization

property of some ligand-gated ionn channels such that if they are open for a long time, they will desensitize or close even though neurotransmitter molecules may still be bound to receptor

Membrane capacitance (Cm)

property of the membrane that allows for the storage of charge. Determines how quickly a neuron's membrane potential can respond to changes in current. The membrane capacitance is proportional to the surface area. The greater the capacitance, the more the signal will attenuate over distance.

membrane capacitance

property of the membrane that allows for the storage of charge. Determines how quickly a neuron's membrane potential can respond to changes in current. the membrane capacitance is proportional to the surface area. the greater the capacitance the more the signal will attenuate

neuron number

proportional to target size

What were the main contributions of Bernard Katz to neuroscience?

proposed and provided evidence for the quantal, vesicle, and calcium hypotheses set the stage for the SNARE hypothesis, which is the molecular basis of the other three

contributions of Bernard Katz?

proposed and provided key evidence for quantal, vesicle, and calcium hypothesis (setting stage for SNARE hypothesis, which is the molecular basis for the three)

The Chemoaffinity Hypothesis

proposed by Sperry; Posterior retinal axons project to anterior tectum, Anterior retinal axons project to posterior tectum

What is a muscle spindle and what is its function?

proprioception (info about position in space) - muscle length made of intrafusal muscle fibers

Primary Motor Cortex

provides commands to initiate voluntary movement and control complex movement. Primary motor cortex is topographically organized. The motor cortex, in coordination with other areas of the brain integrates information from multiple sensory systems.

An IPSP located (proximal/distal) to an EPSP may block the EPSP's signal due to shunting inhibition

proximal

Inhibitory synapses are usually found (proximal/distal) to the soma

proximal (close to)

What is depression?

psychiatric disorder, pessimistic views, suicidal, reduced concentration, etc

the falling phase and hyperpolarization is due to not the ______ but to _______

pump; increase in K+ conductance

depolarization in an NMDA receptor will do what?

push Mg2+ out of the receptor that is blocking the pore

number of quantal released after a single presynaptic action potential

quantal content

the average number of quanta released after a single presynaptic action potential

quantal content

How can neurotransmitter release be altered?

quantal content - change in the release characteristics of nerve terminals alter the number of quanta released. Quanntal content sometimes calculated by dividing the amplitude of a synaptic potential by amplitude of a spontaneous "mini". quantal size - mini's amplitude because a mini is a single quantum of release. Synaptic "efficacy" also influennced by postsynaptic mechanisms.

average size of POSTSYNAPTIC membrane depolarization after a fusion of one vesicle with the presynaptic terminal cell membrane (or another single quantal event)

quantal size

Inhibition changes EPSP shape to make the falling phase _______

quicker

Ocular dominance columns in V1

radioactivity in layer 4 is arranged in stripes...

Rising Phase

rapid depolarizing stage of the action potential when the membrane potential quickly rises from around -65 mV (resting potential) to almost +60 mV.

The (ratio/absolute value) of the concentration sets the Nernst potential, and since the outside concentration is much higher, the reversal potential for Ca is (positive/negative)

ratio; positive

Dendrites

receive information, the cell's antennae, studded with many synaptic terminals from other neurons Receptive sites sometimes on spines (little thorny extensions) numerous dendrites per axon number and arrangement of dendrites vary with neuron type

Horizontal cells

receive input from the photoreceptors and project neurites laterally to influence surrounding bipolar cells and photoreceptors

dendrites

receive signals from neighboring neurons

which of the following are local potentials: receptor potential action potential synaptic potential

receptor potential, synaptic potential

EpH A

receptor tyrosine kinase for Ephrin A

1a afferent in spindle: what kind of potential? Local/propagated? AM or FM? Analog (graded) or digital?

receptor; local; AM; analog

Muscarinic ACh receptor

receptors in heart -Muscarine is the agonists

Delayed Rectifier

refers to voltage gated potassium channels. As they open slower than voltage gated sodium channels, and since EK is hyperpolarized relative to ENa, they rectify or return the membrane potential to a negative value.

delayed rectifier

refers to voltage gated potassium channels. As they open slower than voltage gated sodium channels, and since E_k is hyperpolarized relative to E_Na they rectify or return the membrane potential to a negative value.

Ohm's Law

relationship of current and voltage through any conducting medium V = IR

Ohm's Law

relationship of current and voltage through any conducting medium. Traditionally V = IR. Here Iion - gion( Vm - Eion).

Conductance (g)

relative ability of charge to move or pass through a material.

conductance

relative ability of charge to move or pass through a material.

resistance

relative difficulty in passing an electric current through a material

Resistance (R)

relative difficulty in passing an electric current through a material. Units = Ohms (Ω)

which period in the action potential has a high (but not infinitely high) threshold?

relative refractory period (some channels are closed, but fewer than normal because some are still still inactivated-and those inactivated channels contribute to like an infinitely high threshold)

how does gherlin work?

released from empty stomach, acts on Rs in hypothalamus

sonic hedgehog

released from the notochord at the ventral end of the spinal cord that decreases in concentration as it goes ventral

Glutamatergic

releases glutamate as it's neurotransmitter doesn't mean it has glutamate receptors

Pituitary

releases hormones on command from hyporthalamus

prospective memory

remembering to do something at some future time

Knock out mouse

removing genes. Can now do this with CRISPR method but generally ... (1)Homologous Recombination -- construct mutated gene to be "knocked out." Insert this "targeting/ expression vector" into the cell and it will sometimes recombine with the native gene "homologously," replacing it in the genome so that one copy of the gene is mutated (2) Embryonic Stem Cells -- do homologous recombination in ES cells so that your mutant cell gives rise to a mutant embryo (3) Germ Line Chimerism -- insert the target vector into a mouse so that the mouse is "spotty" with the mutated gene. Then cross and reproduce till you get full/homologous KO mice

slit

repels neurons as they approach the midline

What is a vocal learner and what animal species are vocal learners?

require exposure to sounds of other individuals in order to produce and shape their own sounds e.g. Zebra Since and Song learning

vocal learners

require exposure to sounds of other individuals to produce/shape their own song

Ephrin A

retinal axons bind to it to explain anterior, posterior difference

The most widespread way of removing neurotransmitter from the synaptic cleft is

reuptake, in which the transmitter is transported back into the presynaptic terminal

dopamine

reward

Central Pattern Generator

rhythmic, subconscious alternation patterns (swinging arms, walking, etc). Found in the Spinal Cord. Activated by Tonic/Continuous activity from the brainstem.

permeability of Na increases in which phase of the action potential?

rising phase

lateral hypothalamic

sLim

what are the major planes of section of the brain?

sagittal, coronal, horizontal

the propagation of an account potential along a myelinated axon from one node to the next

saltatory conduction

fat and katz

saw passive spread and decay of depolarization as they moved away from the stimulated end-plate.

What is a commercial use of inhaled oxytocin?

scams to attract or connect with people

microglia

scavengers

Short-term memory lasts

seconds to 30s (someone tells you their phone number that you then type). In certain situations, referred to as "working memory" as when an animal searches a number of sites sequentially for an object and skips places recently visited

Short-term memory

seconds to minutes; working memory

Parvocellular cells of the hypothalamus

secrete releasing hormones into the anterior pituitary where they trigger or inhibit hormone release

Netrin

secreted by ventral midline spinal cord cells

netrin

secreted by ventral midline spinal cord cells to attract axons

regionalizatin

segmentation and segmental identity

aspects of language learning

semantics, syntax, morphology, phonology, prosody

Magnocellular cells of the hypothalamus

send axons to the posterior pituitary where they secrete hormones into the bloodstream

Growth cone defined

sense cues in the environment, react, and are, in turn, altered to be ready for next clue involved in axon guidance The Navigator - the tip of the growing axon Very specialized structure and has seeking behavior

How are sour and salt tasted?

sensed by ion channels activated by Na+ and H+; ion flow depolarizes sensory cell -> release of transmitter into gustatory fibers -> project to brain

Briefly describe how sour taste is sensed

sensed by ion channels that carry or are activated by H+ The ion flow depolarizes the sensory cell, leading to the release of transmitter onto the gustatory fibers projecting into the brain the same thing happens for Salt taste -- just activated by Na+ rather than H+

Thalamus

sensory and motor relays and gateway to the cortex

thalamus

sensory and motor relays and gateways to the cortex

Intrafusal

sensory fibers that detect stretch of the muscle (1E-6)

Sensory PNS

sensory neurons - somata outside spinal cord Sensory Receptor -> Sensory Neuron -> Dorsal Root ganglion -> Dorsal Horn one axon from sense organ, one axon enters the spinal cord, collected into dorsal root ganglia

botulism

could be muscle weakness; paralysis

Memories will

morph with each recall

Hox genes

morphogens at anterior and posterior ends

Depression

most common of major psychiatric disorders

immediate, short term, and long term

three general classes of memory

endoderm, mesoderm, ectroderm

three germ layers

pathway, target, address

three phases of axon outgrowth

What are the sources to the alpha motor neurons?

1) Dorsal root ganglions (sensory) 2) Upper motor neurons 3) Spinal interneurons

Spatial summation

2 or + inputs from different presynaptic cells sum together then cell reaches threshold and action potential is generated

Alpha Motor Neuron

(Lower Motor Neuron) This type of neuron innervates extrafusal muscle

Postsynaptic Changes

-Changes in number of or responsiveness of inotropic receptors can lead to rapid changes in synaptic efficacy

The hypothalamus integrates signals from the exterior and internal worlds, and coordinates a 3-part response. What are the 3 components of the response?

(1) Autonomic - sympathetic/parasympathetic (2) Motor - behaviors (3) Endocrine - hormones

Describe how attractive and repulsive cues guide axons across the midline

(1) Netrin is secreted by ventral midline spinal cord which attract axons with netrin receptors to midline (2) axons approach/cross midline are forced to take up the "Robo" receptor which is produced by midline cells (3) prevents recrossing because axons expressing the "Robo" receptor are repulsed by the "Slit" secreted by midline cells

What are the 9 main steps in mammalian neural development?

(1) Neuralation (2) Regionalization (3) Neurogenesis (4) Migration (5) Differentiation (6) Programmed Cell Death (7) Axon Guidance (8) Synapse Formation (9) Synaptic Rearrangement

Trace the flow of visual info from the right visual field to the left primary visual cortex. Label the the relevant nasal and temporal retina regions, the optic nerve, the chiasm, the optic tract, the lateral geniculate nucleus of the thalamus, the optic radiation, and the primary visual cortex

(1) R and L optic nerves go to optic chaism (2) cross at chasm so that the L visual field from both eyes projects to the R cortical hemisphere and the R field to the L hemisphere. The nasal part of the retina crosses to contralateral side, the temporal part remains on the ipsilateral side (3) after decussation at the optic chaism, you follow the the R and L optic tracts containing ipsilateral, temporal, and contralateral nasal Retinal Ganglion cell axons (4) then the L and R visual fields enter the R and L lateral geniculate nucleus, respectively, in the thalamus (5) the R and L optic radiations exit the thalamus to the primary visual cortex (aka area 17, V1, or the striate cortex) of the R and L occipital lobes of the cerebral cortex

What are 7 taste modalities? Which are the four classical ones?

(1) Sweet (2) Salt (3) Sour (4) Bitter Umami CO2 Fat Water Calcium

What are 3 ways in which the critical period for audiovisual mapping in owls can be extended or reopened?

(1) cause plasticity in adolescence -- fit owl with prisms in critical period, remove when adjustment complete, refit prisms in adulthood -> more remapping (2) Incremental learning -- prisms of increasing strength fit successively rather than strong all at once (3) Increased motivation/attention -- more remapping when owl cared about outcome

What are 4 factors that hinder regeneration of central neurons and what approaches do they suggest for improving regeneration?

(1) components of myelin inhibit cell growth -- therapy: get rid of the inhibitor or block its receptors on neurons (2) growth promoting substances present during development are absent in the adult pathway -- therapy: add growth promoting substances (3) astrocytic scar tissue blocks axon growth -- therapy: inject enzymes that dissolve the scars (4) problems with neuron/decreased ability to reenter growth state -- therapy: manipulate neurons to promote growth

List 4 symptoms of schizophrenia

(1) disorganized thoughts and language (2) Delusions and Hallucinations (3) Bizarre behavior (4) Inappropriate or flat affect (5) lack of motivation and insight

What are 3 lines of evidence for a critical period in human speech learning?

(1) learning a second language is easier when young - otherwise accent and grammar issues nearly inevitable (2) children recover better from damage than adults do (3) children raised without hearing speech may find it impossible to learn speech later

why is the inside negative?

(1) membrane of a resting neuron is more permeable to K_ than others (and its equilibrium potential is -80mv) (2) more K+ inside than out (3) Na+/K+ ATP pump

Extrafusal

(Intrafusal/Extrafusal) Muscle fibers: contract muscles. More numerous. Make up most of muscles. (1E-7)

why to delayed rectifiers return the membrane potential to a negative value

- open slower than VGNaC - EK is hyperpolarized relative to ENa

if you're drawing a subthreshold EPSP, make sure your amplitude is below

-40mV

what is neuron threshold potential?

-50mV

resting potential of membrane

-60mV

Equilibrium potential of Cl-

-65 mV

Equilibrium potential of CI-

-65mV. lower concentration inside.

Equilibrium potential of K+

-80mV. higher concentration inside.

Synapse

-A junction between the axon of a neuron and the dendrite of another -Two types of synapses Chemical Synapses Electrical Synapses For more information please see notes

Versatility of GPCR signaling

-Amplification -Diff GPCRs- diff effects on same enzyme -Affect channels and gene expression in nucleus

"Residual Calcium" hypothesis

-Ca++ enters to trigger transmitter release, then is removed. -When second stimulus arrives soon after the first, "new" Ca++ enters before the Ca++ from the first pulse is fully removed. -Number of vesicles released proportional to Ca

Oligodendrocytes

-Located in CNS -Myelinating axons within the CNS. -Lay down myelin around some axons myelin: lipid-rich wrap, effects on speed of transition of electrical signals

Astrocytes

-Located in CNS: brain and spinal chord -Starlike appearance -Maintain appropriate chemical environment for neuronal signaling blood-brain barrier -Influence construction of synaptic connections -Retain some characteristics of stem cells: Aid in recovery of neural injury

The Dendrites

-Many dendrites leave the soma -receptive site of the cell -studded with synapses with thorny receptors called spines -type of neurite

Schwann Cells

-Myelinating axons within the peripheral nervous system (PNS) -Schwann cell wraps itself many times around a single segment of one axon.

Glial Cells

-Non neuronal cell in the NS -No direct participation in synaptic transmission support/define synaptic contacts -Maintain ionic mileau (environment) of nerve cells -Modulate the rate of nerve signals -Modulate synaptic action by controlling uptake and metabolism and neurotransmitters -Aid in recovery of neural injury -Facilitate connective flow of interstitial fluid through brain during sleep

Golgi Appaatus

-Secretion and transport of proteins. -Folded membranes

The Axon

-Single axon leaves the soma -Unique to neurons -No rough ER, no polyribosomes--not self sufficient -Better conduction=fatter axon

Stem cell

1) Can divide to produce at least one daughter just like itself 2) Turns into a more differentiated cell (including more stem cells with more restricted potential)

What are three ways of extending critical period?

1) Cause plasticity in adolescence 2) Incremental learning 3) Increased motivation/attention

Inputs to Motor Neurons

1) Dorsal root ganglion cells (sensory) 2) Upper motor neurons 3) Spinal interneurons (inhibitory and excitatory)

The Nssl Stain

-Stains the nucleus and surrounding material within a neuron.

-Sub threshold pre-synaptic events

-Times when the stimulation is failing to let enough Ca in to cause a release of neurotransmitters

Ribosomes

-Translation Assembles proteins from a.a. according to the mRNA sequence -Rough ER ribosomes make proteins for axons

In reality neurons integrate 1000s of inputs

-multiple EPSPs and IPSPs

Chemical synapses

-presynaptic and postsynaptic neurons are separated by a physical gap called the synaptic cleft

Neuromuscular junction

-synapses called end plates between spinal motor neurons and skeletal muscle cells

.

.

total end-plate potential if the contents of each vesicle cause a change in membrane potential of only about 0.4 mV

. Released in packets if 1 packet is .4 mV then 100 would be 4 mV

What is the trophic hypothesis for neuronal survival?

. The target affects survival (not production or differentiation) of neurons.

The Brain Distribution of Catecholamines

...acetylcholine is the transmitter at the neuromuscular junction and is excitatory at those synapses, and that glutamate is the major excitatory transmitter in the brain, while GABA is the principal inhibitory transmitter in the brain. In addition to these transmitters, the brain has a wide distribution of neurons that use Dopamine, norepinepherine, and serotonin.

what's the conduction velocity of an action potential

.5 -120 m/s

if the extracellular space is 100mM K+ then the membrane potential of a glial cell is....

0 mV

Three Events of Action Potential

0. Triggering event that depolarizes the cell body, positive ions flow in. Ions pass through channels that open when a neurotransmitter binds to channel. 1. Depolarization- makes the cell less polar. Voltage-gated sodium channels at axon part closest to cell body activate because of depolarized cell body. Axon depolarized, once one channel opens then positive feedback for others. Neuron briefly becomes positively charged. 2. Repolarization - brings the cell back to resting potential. Inactivation gates of Na+ channel close, stopping inward rush of + ions. K+ channels open, more K+ exit than come in. Cell loses positively charged ions, returning back toward resting state. 3. Hyperpolarization - makes the cell more negative than its typical resting membrane potential. K+ channel stays open a bit longer as action potential passes through, continuing to let positive ions exit. This makes it get even more negative than resting state.

when do EPC's reverse

0mV

Serotonin has only

1 ionotropic receptor, most happen through metabotropic.. HOMOLOGOUS nicotinic ACh receptor.. Has excitatory effect on cell at resting potential

how much of a delay is there in opening up VGKC?

1 msec

What are the phases of axon outgrowth?

1) "Pathway" selection (E.g.: ipsi or contralateral at the optic chiasm_ 2) "Target" selection (lateral geniculate vs medial geniculate) 3) "Address" selection (E.g.: layers 2, 3, and 5; Dendrites of geniculocortical cells)

What changes in the brains of people with Alzheimer's disease?

1) Atrophy: Progressive, gradual degeneration 2) Amyloid plaque: main component now known to be aggregates of a peptide called Aβ 3) Tangles: main component now known to be aggregates of tau (which is a protein normally associated with microtubules)

What are the classes of skeletal muscles

1) Axial (neck, back ribs) 2) Proximal (girdle; where limbs are in space) 3) Distal (many and get smaller the farther you get from the periphery)

Why is LTD of Schaffer synapses a good mechanism for info storage?

1. Coincidence detector 2. LTP is input specific 3. Associativity Ass

What are the five critical factors that regulate effectiveness of synapses?

1. Distance matters: the farther an EPSP is from the trigger zone, the less powerful it is. 2. Things don't add up right: the synaptic potentials of different axons sum in a nonlinear way 3. A little bit of gcl- goes a long way: IPSPs interposed between EPSPs and initial segment block the EPSPs form reaching threshold 4. Piggybacking: temporal summation 5. No piggy back: inhibition changes shape of epsp preventing temporal summation

Heretosynaptic Facilitation

1. Excitatory transmitter released 2. GPCR activated, cyclic AMP formed, leads to inactivation of K channels (terminate AP) 3. Nerve terminal stays depolarized longer 4. Ca channels remain open longer -> more neurotransmitter released

How "modulatory" synapses work

1. Modulator released 2. Activates receptor, GPCR, leads to second messenger 3. Changes sensitivty of inotropic receptor to transmitter released from nerve terminal

Evidence for Vesicle Hypothesis

1. Numerous vesicles in nerve terminnals (presynaptic part of synapses) 2. Omega figures seen if the nerve is examined shortly after it is stimulated 3. Prolonged high frequency stimulation leads to depletion of vesicles 4. Neurotransmitter has been isolated from vesicles. Each vesicle contains thousands of neurotransmitter molecules 5. Membrane for synaptic vesicles is retrieved from the plasma membrane by a "vesicle recycling" process Therefore synaptic vesicles are the anatomical substrate for quanta, 1 quantum = 1 vesicle.

Compartments of Neurons

1. Soma cell 2. The Axon 3. Nerve Terminal 4. Dendrites

Steps in myotatic reflex

1. Stimulus : tap patellar tendon 2. Transduce stimulus into electrical signal called receptor potential that changes the sensory receptor cell's membrane potential. The stretch of the axon causes + charged sodium ions to flow into the axon making the membrane potential less negative. 3. Encode. Convert sensory information receptor potential into action potential frequency information in the form of propagating "all or none" action potential that go via peripheral nerve. Only happens if receptor potential is strong enough to depolarize the axon enough to bring it to "threshold" for initiating a propagating action potential. The stronger the receptor potential the greater the frequency of action potentials. 4. Sensory-motor synaptic connection between la axon and motor neurons convey the la sensory neuron signal to the "postsynaptic" motor neuron. These elecit synaptic potentials in the connected motor neurons. Synaptic potentials are like receptor potentials in that they are local and that they only elicit action potentials in motor neurons if they cause the motor neurons trigger zone to reach threshold. 5. Motor neuron action potential is elicited by temporal summation of a sequence of synaptic potentials that combine to reach threshold at the trigger zone located at the initial segment of the motor neuron axon 6. Muscle fiber activation at neuromuscular junction by motor neuron synaptic potential. Each muscle fiber is depolarized to threshold by one large synapse, the neuromuscular junction. When muscle fiber reaches threshold at NMJ it activates an action potential that causes the whole muscle fiber to contract.

Trophic theory of neuronal survival

1. The target affects survival (not production or differentiation) of neurons. 2. Neuron number is proportional to target size 3. Hypothesis: target secretes a limited amount of a "neurotrophic" molecule needed for neuronal survival

first 2 factors that regulate the effectiveness of synapses

1. further from initial segment = less powerful 2. synaptic potentials of different axons sum in a non-linear way

NGF (nerve growth factor)

1. it is produced by the targets of axons in the sympathetic division of the ANS. ...... 2. the injection of antibodies to it into newborn mice resulted in total degeneration of the sympathetic ganglia. 3. when it produced and released by the target tissue, is taken up by the sympathetic axons and transported retrogradely, where it acts to promote neuronal survival. 4. if axoplasmic transport is disrupted, the neurons will die despite the release of NGF by the target tissue

Describe the way in which the neural plate, neural fold, neural tube, and neural crest arise

1. neural plate folds into neural groove 2. walls of groove (neural folds) move together and fuse to form neural tube 3. some of neural ectoderm is pinched off and lies lateral to neural tube—called neural crest Neural tube becomes central nervous system Neural crest becomes peripheral nervous system

microcephaly

2-3x too small; neurogenesis

how wide is the synaptic cleft

20 nm

Genome

20,00 genes; 14,000 expressed in the nervous system

5 factors that regulate the effectiveness of synapses

1. the farther an excitatory synapse from the initial segment (trigger zone) the less powerful it is. This is because dendrites have low membrane resistance (resting K permeability), high capacitance (not myelinated) and large axial resistance. Excitatory synapses are supra-threshold because they are located close to the initial segment. Synapses located on a distant branch are sub-threshold at initial segment despite giving rise to a large depolarization at synapse site. 2. Synaptic potential of different axons sum but in a non-linear way. It is not linear because the closer the membrane potential gets to Reversal potential (~-10mV), the lower the net driving force. A synapse can't depolarize the membrane beyond the reversal potential, so adding many synapses together can only approach ~-10mV and each additional input has less effect. 3. IPSPs interposed between an EPSP and the initial segment block the EPSP from reaching threshold. This is called shunting. 4. Temporal summation allows an EPSP to "piggy back" on another. EPSP shape has a fast rise and slow fall. During the rise the LGICs are open so membrane resistance is low and charge passes through the membrane quickly. During the fall LGICS are mostly closed so membrane resistance is higher and its takes a longer time to remove the added positive charges, hence the filling phase is slower than the rising phase. 5. Inhibition changes shape of EPSP preventing temporal summation. Concurrent inhibition decreases the membrane resistance allows the falling phase to return to the resting potential more quickly (via CI- entry) so summation is less likely to occur

Characteristics of Neurons

1.Compartmentalization of structure and function reception---integration---output dendrite soma cell axon 2. Electrical excitability 3. Synaptic connections 4. Most neurons are not replicable, do not divide

what makes a neuron

1.compartmentalization of structure and function: receptive regions (mostly dendrites) integration (cell body or soma) and output (axon) 2. electrical excitability 3. synaptic connections 4.all (most? are non-replicating

first events for synaptic transmission

1.transmitter is synthesized and then stored in vesicles 2. An action potential invades the presynaptic terminal 3. depolarization of presynaptic terminal causes opening of voltage-gated Ca2+ channels 4.influx of Ca2+ through channels

O:I Ca

10,000: 1

O:I Na

10:1

O:I Cl

11.5: 1

Equilibrium potential of Ca++

120mV

Equilibrium potential of Ca2+

120mV. lower concentration inside.

Pk: Pna: Pcl

1: .025: .45

O:I K

1:20

what two axons innervate the muscle spindle?

1a afferent axon gamma motor neurons

Neurulation

1st step in development of nervous system 3 primary germ layers (endoderm, mesoderm, and ectoderm) give rise to everything neural tube becomes CNS. neural crest becomes PNS

action potential distance

20cm

final 3 factors that regulate the effectiveness of synapses

3. IPSPs interposed between an EPSP and the initial segment block the EPSP from reaching threshold 4. temporal summation allows EPSPs to piggyback 5. Inhibition changes shape of EPSP block out temporal summation

G-proteins have how many parts

3: alpha, beta, gamma

MS can be treated with _______ which blocks _____

4 AP: voltage gated K+ channels

what chemical blocks voltage-gated potassium channels?

4-AP

middle events for synaptic transmission

5.Ca2+ causes vesicles to fuse with presynaptic membrane 6.Transmitter is released into synaptic cleft via exocytosis 7.transmitter binds to receptor molecules in postsynaptic membrane 8.Opening or closing of postsynaptic channels

AChR is ___ protein subunits, each with ___ transmembrane domains

5; 4

Equilibrium potential of Na+

60mV. lower concentration inside.

final events for synaptic transmission

9. Postsynaptic current causes excitatory or inhibitory postsynaptic potential that changes the excitability of the post synaptic cell 10.removal of neurotransmitter by glial uptake or enzymatic degradation 11.retrieval of vesicular membrane from plasma membrane

Dendritic spines

A small protrusion on a dendrite of some neurons that receives a synaptic connection from axon terminals and compartmentalizes the chemical and electrical signals.

Stem cell

A cell that can divide to produce at least one daughter cell just like itself or turn into a more differentiated cell (including more stem cells with more restricted potential).

Positional information

A chemical (morphogen) released from one end of the axis forms a gradient, and the concentration of morphogen determines which genes are activated. The pattern of gene expression, in turn, endows the cell (or tissue) with specific. The idea that maybe for some reason there will be part of animal that will become specialized and secrete some kind of chemical and as that chemical is secreted, it will create a gradient which can turn on gene in different places.

What is the difference between a closed Na+ channel and an inactivated Na+ Channel?

A closed Na+ channel is able to be activated/opened with a strong enough depolarization an inactivated Na+ channel cannot be opened for a few seconds by any stimuli

end plate current (EPC)

A macroscopic postsynaptic current resulting from the summed opening of many ion channels; produced by neurotransmitter release and binding at the motor end plate. causes the postsynaptic membrane potential to depolarize. The depolarizing potential is the EPP, which triggers a postsynaptic action potential by opening voltage-gated Na+ and K+ channels. More inward current at potentials more negative than Erev as the electro-chemical driving force, Vm-Erev is negative. EPC will become smaller at potential approaching Erev because the driving force is reduced. At potentials more positive than Erev the EPC is outward as driving force is reversed in direction.

adenosine

A neuromodulator which builds up in extracellular space inhibiting mesopontine cholinergic neurons that regular attention and arousal as you stay awake. (Neuromodulator (NM) is a NT that is not reabsorbed by the pre-synaptic neuron or broken down into a metabolite... they spending a significant amount of time in the cerebrospinal fluid (CSF))

Organizer experiment

A portion of the mesoderm called "the organizer" normally gives rise to the notochord, beneath the neural tube. Spemann and Mangold transplanted a second organizer into an embryo. It INDUCED a second body axis, including the neural tube.

Induction

A portion of the mesoderm called the organizer normally gives rise to the notochord, beneath the neural tube. Researchers transplanted a second organizer in an embryo. It induced a second body axis, including the neural tube. One piece of tissue by proximity can take another piece of tissue nearby and cause it to organize

List three ways motor neuron are mapped.

A segmental map that relates to the ROSTROCAUDAL POSITION OF THE MUSCLE IN THE BODY, A MEDIOLATERAL MAP THAT RELATES TO THE PROXIMAL TO DISTAL, FLEXOR TO EXTENSOR MAP

Splice Variants

A single gene encodes different information for various protein products

What is a decussation?

A site of crossing, The chiasm is a site of decussation. The crossing of a fiber bundle from one side of the brain to the other.

Major neurotransmitters

ACh;Excitatory;Choline +acetly Coa

alpha betarotoxin blocks

AChR

myasthenia gravis is a disease involving

AChR

what's bigger: AChR or VGIC

AChR

which channel does water entourage go through: AChR or VGIC?

AChR

What do a GABA channel and an AChR channel have in common?

AChR -- promiscuous cation channel (Na+ and K+ receptors), excitatory GABA -- anion selective channel (Cl- receptors), inhibitory Both Ligand-gated channels. Receprotrs similar, but AChR pores lined with neg amino acids, Gaba are lined with neutral or positive AAs

Name the main excitatory neurotransmitter in the brain and list its main receptor types.

AChR and Glutamate Glutamate-- in the CNS the fast, usually weak EPSPs are due to Glutamate release from axon varicosities onto dendritic spines. Ionotropic Receptors (let ions flow) -- AMPA Receptor (main glutamate channel, Na+ ad K+) & NMDA Receptor (V-gated and Ligand Gated channels, Na+, K+, Ca++ -- lets Ca++ enter during large depolarization which is important for plasticity) Metabotropic Receptors (changes metabolism) -- G Protein coupled AChR receptors -- Na+ and K+

Did AJ use tricks?

AJ could remember a ton of dates and episodic memories connected to certain days her trick was she arranged calendar in a spatial way - like a clock - and also had OCD tendencies with dates

Scientists who invented a staining technique that lets scientists visualize nervous tissue under light microscopy

Camillo Golgi

What is reciprocal inhibition?

ALLOWS JOINT MOVEMENT INHIBITING ANTAGONIST MUSCLE

Ionotropic glutamate receptors

AMPA receptors

Reticular Theory

Camillo Golgi -No individual cell entities -Nerve Cells were connected to their neighbor forming continuous interconnected nerve cell networks

Associativity

If one pathway is weakly activated at the same time the neighbor is strongly attached I both will undergo LTP

eye patching?

If the left eye inputs from nearby regions of the retina are activated at the same time, they will end up at the same cells. Tend to segregate from each other if neurons fire at different times

Ion that blocks the pore of an NMDA receptor at hyper polarized potentials making the channel voltage dependent

Mg++

What does CPG stand for? What is it? Where in the nervous system does the CPG for walking reside?

Central Pattern Generator CPGs are activated by tonic descending activity (continuous simulation) from the brainstem or cortex. Gives rise to rhythmic activity of extensor and flexor muscles - allows locomotion brainstem or cortex

.

Central Pattern Generators (CPGs)

5-HT3

Channel is permeable to Na+ and K+ ions. ONLY 5-HT RECEPTOR THAT ISNT METABOTROPIC.. Structurally similar to the nACh-R, except that it binds serotonin instead of ACh. ItS activation leads to a depolarization of the cell

How do NMDA receptors act as coincidence detector

Channel opens only when glutamate is bound to the receptor and postsynaptic cell is depolarized

What do axons with netrin receptors do?

Chemotax to the midline

Removal of neurotransmitter from the synaptic cleft

Cholinergic synapses are exceptional because ACh can be broken down by enzymatic action in the synaptic cleft

Where are the conscious sensations of emotions located?

Cingulate, parahippocampal and prefrontal cortex

GABA channels conduct this ion

Cl-

Gene

Coding of DNA sequences (exons)

Compare and contrast: Communication, Language, and Speech

Communication - innate, conveys information Language - innate and learned, convey info and new ideas Speech - word production

What are the main abnormalities in split brain patients? Are they easily noticed?

Complementary evolution of both hemispheres each with advanced functions and each hemisphere seems to have conscious awareness - right hemisphere mute but expresses annoyance when left says something the it thinks is wrong

Heteronymous

Connection: muscle spindle stimulates an inhibitory synapse which stimulates this muscle not to contract. in reciprocal inhibition

When we say neural connections are specific, what do we mean?

Connections are specific and is evident everywhere in the nervous system. The nervous system is partitioned into many separated streams: motor, sensory, autonomic, enteric. Topographic maps within each. Even within one stream high degree of specific.

T or F: If there is a presynaptic alteration, quantal content will change

True

How, in general, are recognition molecules deployed in the tectum and retina

IN GRADIENTS

internal representation of a movement

INDEPENDENT OF THE SPECIFIC MUSCLES USED OR THE WAY GOAL IS ACHIEVED, ONLY SPECIFIES THE OUTCOME

T or F: standard way of "spontaneous" mEPP is Ca2+ independent

True

parkinson's disease

INHIBITION OF WILLED MOVEMENTS BECAUSE OF MORE INHIBITION OF THALAMIC INPUT TO PREMOTOR CORTEX

Huntington's disease

INITIATION OF MOVEMENT IS AUGMENTED BECAUSE LESS INHIBITION OF THALAMIC INPUT TO PREMOTOR CORTEX

How does inhibition on a proximal dendrite affect more distal dendritic excitatory synaptic potentials? Why?

IPSPs interposed between an EPSP and the axon hillock block the EPSP from reaching threshold because IPSPs cause EPSPs to attenuate to nothing before reaching the soma by allowing Cl- to rush in and keep the membrane potential at equilibrium potential (-65mV)

T or F: the branch of a dorsal root ganglion cell that sends action potentials toward the cell body is called a sensory axon

True

Types of Glial Cells

Astrocytes Oligodendrocyte Microglial

Why is the Na+/K+ pump important?

At Vrest, Na+ will continue to move down gradients, as will K+. Eventually the concentration differences across the membrane would disappear, creating disastrous consequences for neural signaling. Thus there needs to be a means to maintain K+ high inside, Na+ low inside

Define desensitization. Provide an example

If AChRs or other ligand gated ion channels are open for a long time then the channel closes (analogous to Na+ inactivization in V-gated channel). EG. Succinyl choline is not cleaved easily by Each Esterase and so causes desensitization of the AChR and paralysis

List 5 differences between the channels associated with action potentials and those associated with neuromuscular junction

AP Channels - two channels (Na+, K+) voltage gated gNa+ then gK+ (delayed rectifier) affected by TTX protein, Diseases -some channelopathies AChR Channels - 1 channel Ligand Gated Simultaneous g's affected by alphaBTX poison diseases - myasthenia gravis

What is M1? What does it innervate? How is it different from other motor areas in the cortex?

AREA JUST ANTERIOR TO THE CENTRAL SULCUS THAT DETECTS STIMULI TO MOTOR NEURONS- DIFFERENT BECAUSE IT HAS A HIERARCHICAL SYSTEM WHERE SOME MOVEMENTS ARE MORE CONNECTED

Biological Amines

Catecholamines: epinephrine, norepinephrine, dopamine; excitatory;Tyrosine Setotonin (5-HT); Excitatory;Tryptophan

Define local potential and graded potential. Which of the following are local potentials: receptor potential, action potential, synaptic potential?

All but action potential? Local potential -- The same as graded potential but applies to a specific location along the membrane. Graded potential -- Changes in the membrane potential that vary in size, as opposed to being all-or-none. This is a general term that applies anywhere and anytime except when action potentials are firing. Receptor potential -- a stimulus induced change in the membrane potential of a sensory receptor Synaptic Potential -- The same as the graded potential except only applies at post-synaptic areas, includes excitatory and inhibitory potentials. Graded potential -- Changes in the membrane potential that vary in size, as opposed to being all-or-none. This is a general term that applies anywhere and anytime except when action potentials are firing. Action potential -- Action potentials sweep like a wave along axons to transfer information from one place to another in the nervous system.

extrafusal

Alpha Motor Neuron/Lower Motor Neuron innervates _____ muscle

What are the main components of amyloid plaques and neurofibrillary tangles?

Amyloid plaques - aggregates of a AB peptide Tangles - aggregates of a Tau Protein

What is the shape of an EPSP? How is this shape related to membrane resistance?

An EPSP has a fast rise and a slow fall. During the rise the Ligand Gated Ion channels are open and membrane resistance is low so the synaptic current is fast. During the fall the LGICs are mostly closed so membrane resistance is higher and it takes longer to remove added positive charges - passive discharge, slow

Synapse Processes

As action potential travels down axon, positive ions flood into cell. Influx reaches axon terminal which triggers voltage-gated calcium channels to open and letting calcium ions flow into the cell. Ca+ triggers vesicles to fuse with cell so that content can be released into synaptic cleft. These neurotransmitters will either cause the signal to propagate (excitatory) or cancel (inhibitory). The post synaptic terminal in neighboring cell is full of neurotransmitter receptors, ligand-gated ion channels that open in response to being bound by specific neurotransmitters. If excitatory, positive ions will depolarize cell body. If inhibitory, it will hyper polarize the cell body.

What happens to receptive field properties beyond V1?

As we move progressively higher sensory processing centers of the brain receptive fields might continue to get progressively more complicated. The dorsal stream appears to serve the analysis of visual motion and the visual control of action. The ventral stream is though to be involved in the perception of the visual world and the recognition of objects.

The Soma Cell

Cell body - cytosol: intracellular fluid of cell rich in K+ -extracellular fluid of cell: rich in Na- -contains: nucleus golgi apparatus ribosomes mitochondria cytoskeleton

metabotropic receptors

Bind neurotransmitter but then bring about the opening and closing of physically separate channels via the activation of intermediate molecules called G-proteins

Olfactory sensory neuron

Bipolar neurons with cilia that extend into the nasal passage where the olfactory receptors located on the cilia can interact with odorants in the nasal passage. Olfactory sensory neurons send their axons through a portion of the skull (the Cribriform plate) and onto the olfactory bulb.

What is the taste receptor GPCR families called? How many receptors are in each family? What do they sense?

Bitter, sweet and umami tastes bind to GPCRs, activate them and form second messengers that activate cation channels, depolarize the cell, and release neurotransmitter Two groups of GPCRs - T1Rs and T2Rs T2Rs = bitter tastes T2R2 + T1R3 = sweet T1R1 + T1R3 = umami

What are microtubules and why are they so important in neurons?

Microtubules are part of the cytoskeleton (structure and transport functions) Microtubules basis of axoplasmic transport -- material enclosed in membrane vesicles walk along microtubules in the axon

Viktor Hamburger and Rita Levi-Montalcini

Came up with the trophic theory of neuronal survival

Regions of the hippocampus

CA1 -neurons form a thick band -receive Schaffer collaterals -axonal pyramidal of CA3

extracellular matrix

COLLECTION OF EXTRACELLULAR MOLECULES SECRETED BY CELLS THAT PROVIDES STRUCTURAL AND BIOCHEMICAL SUPPORT TO THE SURROUNDING CELLS

Ion that catalyzes SNARE protein vesicle fusion

Ca++

Residual Calcium Hypothesis for facilitation

Ca2+ enters to trigger vesicle release, but second stimulation occurs soon after the first, and so Ca2+ hasn't been completely removed next firing is even stronger because there was more Ca2+

What life style regimens can slow age related synaptic and cognitive decline, at least in experimental animals?

Caloric Restriction and Exercise

Define "critical period" for sensory deprivation

Critical period is a maturational stage in the lifespan of an organism during which the nervous system is especially sensitive to certain environmental stimuli

Axon initial segemnt

Site of action potential initiation

DAVEE mnemonic

DORSAL AFFERENT ... VENTRAL EFFERENT + EXTENSORS extensor (ventral) and Flexor (dorsal)

List the 2 main kinds of human memory and briefly describe how the differ

Declarative/Explicit memories -- available to consciousness and can be expressed inn language. often episodic and/or semantic Procedural/Implicit/Nondeclarative memories -- not easily described with language, skills and learned reactions that are typically retrieved unconsciously they use different neural pathways and structures

Describe a mechanism by which synaptic depression could underlie habituation

Decreased response to a repeated stimulus In aplysia, (touching -> gill contraction) is due to synaptic depression Stimulus -> sensory neuron (presynaptic) -> postsynaptic neuron Recordings from sensory neuron did not decrease, so it must be postsynaptic

What happens to brain mass with age?

Decreases...probably because over time the health of neurons decreases (not number of neurons)

What is DBS? What diseases have been treated with it?

Deep Brain Stimulation -used for Parkinson's and tried for depression

Why is it that the farther away a synapse is from the initial segment, the less powerful it is?

Dendrites are leaky cables with low membrane resistance, high capacitance, large axial resistance,

What does depolarize mean? What does hyper polarize mean?

Depolarize - make more positive, closer to threshold Hyperpolarize - make more negative, farther from threshold

This means you can have short term plasticity where neuron can keep memory of what its doing. The next AP will benefit from previous AP since there will be a little more Ca in pre synaptic cleft so that more neurotransmitters can possibly be released.

If it is a reliable then all vesicles may leave with first AP

ocular dominance histogram?

Has no affect on the histogram but has profound effects on visual perception.

HM's problems

He could not consolidate declarative memory. Devastating memory deficit: normal immediate and short-term memory but no consolidation of short-term declarative memory into long-term.... Intelligence unaffected and spatial orientation severely affected

What technical advance did Hubel develop and why was this important?

He developed the Tungsten electrode which allows for extracellular recording of action potentials in cortical and thalamic neurons. Can record from many cells in the same sitting.

Temporal Lobe

Hearing, Memory, Speech

Why does the axon hillock have the lowest threshold of any part of the neuron?

Highest density of Na+ channels

What is the vertebrate model of Long Term Plasticity

Hippocampus -episodic memory -spatial navigation

Late LTP

Hours after the initial repeated stimulation that induces LTP, structural changes in the synapse occur, including spine motility, an increase in spine size, and insertion of new spines.

Interspecies differences

Humans taste aspartame but mice don't...cats can't taste sweet...Do these differences arise from differences in receptor levels? Found that if you insert human T1R2 into the mouse, the mouse likes aspartame

Describe an experimental result demonstrating that taste modality depends on the taste cell stimulated rather than the identity of the receptor stimulated

Humans taste pheny-glucopyranoside (GP) using T2R16 but mice don't. Expressing human GP receptor (T2R16) in "bitter" cells (using regulatory elements from another "bitter receptor") renders mice sensitive to GP. It acts as an aversive stimulus...they don't like it. In contrast, expressing human T2R16 in "sweet" cells (using regulatory elements from T1R2, the "sweet receptor") makes them like it! It's the CELL not the CHEMICAL that has meaning!!

Hypothalamus

Hunger, Thrist, Body Temperature, Circadian Rhythms

Briefly how are Huntington's and Parkinson's diseases different?

Huntington's: The initiation of movements is augmented because of less tonic inhibition of the thalamic input to premotor cortex. hyperkinetic; flailing movements; genetic disease and people often discover they have it after they have had children so they can pass it on

Briefly, how are Huntington's and Parkinson's diseases different?

Huntingtons - hyperkinetic - initiation of movement augmented because of less tonic inhibition of the thalamic input to the premotor cortex Parkinsons - hypokinetic - the initiation of willed movements is inhibited because of more tonic inhibition of the thalamic input to the premotor cortex

Why does a low dose of strychnine resemble the genetic disease hyperekplexia?

Hyperekplexia (Startle Disease) -- exaggerated, freezing response to small stimuli due to small single amino acid mutations in the glycine receptor that makes it less able to open Strychnine -- blocks the glycine receptor ... causing rigidity or convulsions and seizures

GABA receptor

Hyperpolarizes cell at resting potential, and its composed of 5 subunits

How does the brain keep it's own temperature constant?

Hypothalamus can sense temperature directly via its own TRP channels; doesn't need sensory neurons with TRP channels on ending in skin to send reading to the hypothalamus

our Ohm's law equation

I = g (Vmem - Eion)

What is a reversal potential?

Like the equilibrium potential but applied to a channel, it is the voltage needed to ensure zero net flow of charges through the channel If a channel is permeant to a single ion, then the reversal potential is the equilibrium potential for that ion. At membrane potentials more negative, the ionic currents flow one way and at membrane potentials more positive, they flow the other way. At a specific value, the currents reverse (reversal potential) and the diffusion and electrical forces cancel (the equilibrium potential). Synapses where a channel allows several types of ion through -- not at eq. but the net current is zero AT THE NMJ- The neuromuscular junction Ach receptor channel allows both Na+ and K+ through. So, the reversal potential is neither EK nor ENa, but halfway between these two. At the reversal potential, neither ion is in equilibrium but the influx of Na balances the efflux of K so the net current is zero.

Action potentials versus Local potentials

Local - convey info in their amplitude and duration (graded) Action - convey info in their number and timing (all or none)

what's the difference between local potential and grade potential?

Local potentials are the same as graded potential but applies to a specific location along the membrane.

Differences between Sympathetic and Parasympathetic divisions? Location of ganglia? Segmental origin of preganglionics? Neurotransmitter?

Location of ganglia - S - far from target, close to spinal cord PS - close to target Segmental Origin of Preganglionics - S - thoracic and lumbar PS - cranial and sacral Neurotransmitter - S - norepinephrine PS - acetylcholine

Provide a synaptic mechanism that could associate a sound with fear.

Long Term Potentiation in Amygdala (LTP)

By what developmental measure might human brains be considered unusual?

Longer, slower development Neotony, retention of juvenile features longer susceptibility to environmental influences, plasticity

How was it determined that the ACh receptor at the end plate is permeable to both Na+ and K+?

Lowering external [Na+] (which makes the sodium equilibrium potential more negative) produces a negative shift in the reversal potential

What different functions are served by the lumbar vs. cervical spinal cord

Lumbar - Hips, Quads, Hamstrings, foot, knee, adrenal gland, bladder Cervical - neck muscles, diaphragm, shoulder, wrist, triceps, fingers Divisions of PNS generally relate to their location relative to the body Sympathetic NS comes from thoracolumbar region (cranial area and brainstem and sacral) Parasypathetic comes from the craniosacral region (cervical, thoracic, lumbar)

What are 2 lines of evidence for the dopamine hypothesis of schizophrenia?

MRI and PET Studies showed increased dopamine release in schizophrenics, and that dopamine increase correlated with disease severity chlorpromazine, effective antipsychotic looks/acts like dopamine

Why is 4-AP used as a therapeutic for MS

MS causes demyelination, which leads to a decrease inAP propagation velocity down an axon and eventual loss of signal form the cell body to synaptic terminals. Since 4-AP application results in a slower rate of decay of the AP (also higher peak), it could help prevent signal attenuation in demyelinated axons of MS patients

What are the 3 functional streams of visual info entering and leaving the lateral geniculate? How are they arranged?

Magnocellular - motion - ventral most layers 1 and 2 containing larger neurons Parvocellular - shape - four more dorsal layer Koniocellular - color - just ventral to each layer

neurofibrillary Tangles

Main component known to be aggregates of tau, a protein normally associated with microtubules; located in the neurons themselves

How did studies of morphine lead to discovery of enkephalin?

Many opiates are structurally similar so people started to search for common receptors. The opiate receptors turned out to be GPCRs. So people started searching for natural, endogenous ligands. They found that the ligands turned out to be small peptides, named enkephalins. Like morphine they modulate pain and can be very pleasant (runner's high)

Limbic system

Maybe cortical representation of emotion?

How do meadow voles and prairie voles differ in social behavior?

Meadow - loners, polygamous Prairie - family, social, monogamous

Give 3 examples of transduction that occur in the patellar tendon reflex.

Mechanical (stimulates -> stretch/opening of channels) to Electrical (ions cause current) Electrical (action potential) to chemical (across synapses) Electrical (ions cause current) to mechanical (contraction of quads)

Where does conditioned fear response occur?

Medial geniculate (auditory thalamus) pathway to amygdala needs to be intact.

Brainstem

Medulla and pons maintenance and vital functions e.g.. respiration, circulation, posture

Write the Nernst Potential Equation RT/ZF values for K+, Na+, Cl-, Ca++

Membrane Potential = (RT) / (ZF) × ( log{ [out] / [in] }) K+ = 60 mv Na+ = 60 mv Cl- = -60 mv Ca++ = 30 mv

Write the Goldman Hodgkin Katz equation. Why is it useful? What does it have to do with resting potential?

Membrane potential = (RT)/F × Log( { ( P(K+) × [K out] ) + ( P(Na+) × [Na out] ) + ( P(Cl-) × [Cl in] ) } / { ( P(K+) × [K in] ) + ( P(Na+) × [Na in] ) + ( P(Cl-) × [Cl out] } ) equals membrane potential when multiple different ions are permeable in a NEURON Permeability of P(K+) : Na+ : Cl- = 1 : .025 : .45 represents a steady state but not an equilibrium condition - high [K+] inside and low [Na+] outside

Hubel and Wiesel

Normal ppl: Ocular dominance histogram shows roughly equal likelihood a cortical neuron will be activated by the ipsi- and the contralateral eye Abnormal: if one eye is deprived of vision by patch in early postnatal life then the histogram is shifted in later life-in favor of the un-patched eye.

Glial stem cells

Not any present in the mature brain -Proliferate and generate other glial cells More info on notes

With reference to feeding - What are the main responses to decreased fat levels?

Not enough leptin Response -- Motor: increase feeding behavior/foraging Autonomic: parasympathetic, rest and digest activity Endocrine: blocks catabolism

How well do the Ca2+ extrusion properties work for the presynaptic cell?

Not every action potential causes presynaptic terminals to release neurotransmitter! Some synapses are "unreliable" synapses. One action potential from the presynaptic cell may not be sufficient to produce vesicle release. May be due to the properties, numbers, and locations of voltage-gated Ca2+ channels. May also depend on Ca2+ affinity with a protein found in the neuron's presynaptic vesicles (synaptotagmin- we will talk about this later)

NMDA receptors

Not only requiring of glutamate, requires about 30mV of depolarization to remove Mg block

What is a brain machine interface? Why might our motor system have so little trouble using robotic arms?

ONLY NEED TO HAVE INTERNAL REPRESENTATION OF MOTION- NOT WHICH MUSCLES TO USE

What is the motor cortex homunculus? Why does it look so weird?

OVER-REPRESENTATION OF BRAIN REGIONS THAT ARE REQUIRED FOR MOST COMPLICATED MOTOR BEHAVIORS

What are ocular dominance columns? How are they revealed?

Ocular dominance columns are stripes of neurons in the visual cortex of certain mammals (including humans) that respond preferentially to input from one eye or the other. The columns span multiple cortical layers, and are laid out in a striped pattern across the surface of the striate cortex (V1). REVEALED: Transport of radioactive protein from one retinal to cortex shows the location of the axons that are driven by activity in the injected eye. Radioactive LGN termnals labeled by transsynaptic transport of radioactive proline containing protein injected into only one retina. The ocular dominance columns are the bands of cells extending through the thickness of the striate cortex.

units for resistance

Ohms (Ω)

cilia-->_____-->olf nerve -->glomerulus-->olf tract

Olf R cell

Where is inhibition?

On dendritic shafts, soma, and initial segment of axons

Where is excitation?

On dendritic spines

Differentiation in synapse formation

Organizing and coordination pre- and postsynaptic specializations (synaptic organizing molecules)

By what developmental measure might human brains be considered unusual?

Our brains have a much longer susceptibility to environmental influences—prolonged learning

Retinal ganglion cell (RGC)

Output cell of the retinal that transmits information from the eye to the brain. Only type of neuron in the retina that fires action potentials. There are many different subtypes of RGCs.

visual cortex (especially somata outside layer IV) and those in the LGN or retina?

Outside Layer IV, receptive field properties are binocular (V1 cortical neurons respond to both eyes) and have orientation selectivity of the receptive field in an organized pattern. In the LGN or retina, the receptive fields are monocular and have center-surround.

What are the main differences in receptive field properties of neurons in the primary visual cortex (especially somata outside layer 4) and those in the LGN or retina?

Outside of Layer 4 in the primary visual cortex the receptive fields are binocular and orientation selective! Whereas those in the LGN and retina are monocular and circular (center/surround)

What is the motor cortex homunculus? Why does it look so weird?

Over-representation of brain regions that are required for most complicated motor behaviors. Greater proportion to control face and hands compared to legs and trunk

How do genetic variations in vasopressin and oxytocin receptors influence human behavior?

Oxytocin promotes mother infant bonding by acting on uterus an mammary glands Vasopressin promotes social memory by acting on kidney to control salt balance and blood volume

List three phases of decision making for an axon and give an example of each.

PATHWAYS- IPSI OR CONTRALATERAL AT THE OPTIC CHIASM, TARGET- LATERAL GENICULATE OR MEDIAL GENICULATE, ADDRESS- LAYERS 2,3, OR 5

hree effects that guidance cues can have on a growth cone

PERMISSIVE, ATTRACTIVE, REPULSIVE

topographic specificity of the retinotectal projection.

POSTERIOR RETINAL AXONS PROJECT TO THE ANTERIOR TECTUM, ANTERIOR RETINAL AXONS PROJECT TO POSTERIOR TECTUM

Water

PPK28 depolarizes in response to pure water; it is an osmolarity closed channel

What is the reverse myotatic reflex?

PREVENTS TEARS BY MAKING MUSCLE STOP MOVING -> INHIBITORY

Name 2 anxiety disorders

PTSD, OCD, phobias

What is the "rest and digest" response and what part of the nervous system orchestrates it?

Parasympathetic ANS reduces energy expenditure and builds up reserves (anabolic) Cholinergic Acetylcholine

Flexor Reflex

Part of Spinal Cord Circuitry. Avoids noxious stimuli. (step on a tack)

reciprocal inhibition

Part of Spinal Cord Circuitry. Inhibition of antagonist muscle; otherwise there would be no net movement/action.

myotatic stretch reflex

Part of Spinal Cord Circuitry. Prevents falling (knee reflex).

reverse myotatic reflex

Part of Spinal Cord Circuitry. Prevents tears. Too much strain causes the muscle to buckle and give up.

What are scotopic and photopic vision, and what accounts for the difference between them?

Scotopic = night vision. Because rods are active, light to dim to activate cones Photopic = color/day vision. Because cones are active, the rods are bleached and inactive

facilitation

Second of two closely spaced epsp's are bigger than the first. Because more Neurotransmitter is released (presynaptic) or because there is a higher sensitivity for neurotransmitter (postsynaptic).

Is the mute hemisphere unconscious? What can it do better than the left hemisphere?

Seems not - expresses with facial expression satisfaction or annoyance It is better at copying designs, reading faces, fitting forms to molds, judging whole circle size from small arc, categorizing shapes

List 3 ways motor neurons are mapped

Segmental Map (relates to the rostrocaudal position of the muscle in the body) Mediolateral Map (relates to the proximal (close to body axis) to distal (far from body axis)) Flexor (dorsal) to Extensor (ventral) Map

Action Potential

Self generate wave of electrical activity all/nothing changes in the electrical potential-voltage across nerve cell membrane

Bipolar cells

Send signals from photoreceptors to retinal ganglion cells

Spinal Cord Organization

Sensory axons bundle to form dorsal roots Motor axons bundle to for ventral roots Dorsal and Ventral Roots join to form spinal nerves

Simple Pathways from sensory receptor neuron

Sensory end - sensory axon - spinal cord - thalamus - S1 of SSC (somatory sensory cortex)

What are the two distinct steps in song learning by songbirds?

Sensory learning - bird hears the song of a tutor but it cant sing yet Motor learning - the bird practices and gradually perfects is song as a mimic of his tutor's

Peripheral Nervous System

Sensory, Motor, Autonomic Segmental Arrangement - Cervical, Thoracic, Lumbar, Sacral

The Brain Distribution of Serotonin (5-HT)

Serotonin is another neurotransmitter widely distributed throughout the brain. The cell groups that give rise to serotonin are located in a region called the Raphe nuclei. Serotonin is also know as 5-HT.

expression of emotion?

Sham rage: a controversial term used to describe behavior such as biting, clawing, hissing, arching the back and "violent alternating limb movements" produced in animal experiments by removing the cerebral cortex, which are claimed to occur in the absence of any sort of inner experience of rage

.

Shape, color, position, movement

Did AJ use "tricks"?

She spontaneously arranged calendar in a spatial way—when asked to draw her mental calendar she drew the years in a funny grid then the months in a clock face with Jan at 11 o'clock—this may be her spatial tag (a "trick")

goslings.

Showed that goslings imprinted on first moving object no matter what it is

Optic Nerves

Sight

Compare the receptive field properties of retinal and LGN neurons. Are they similar or different?

Similar to Retinal Ganglion Cells LGN receptive fields -- circular (center-surround) and monocular Outside of Layer 4 in the primary visual cortex the receptive fields are binocular and orientation selective!

Basic Structure for GPCRs

Single polypeptide with 7 membrane spanning alpha-helices

Define strabismus and amblyopia

Strabismus: misalignment of the eyes typically due to a weakness in one or another extra-ocular muscle

Draw a graph of glial cell membrane potential (Y axis) as a function of changing extracellular potassium concentration (X axis, log scale)

Straight line increasing with slope = 60mV/ 10fold change in Ko Glial cell only permeable to K+ hence Eion = memb. pot. So if the extracellular space is 100 mM K+ then the membrane potential of a glial cell is 0 mV then as change [extracellular], the men. potential will linearly increase with 60mV/10 fold change in K+ V = 60 Log [K+ out] / 100 linear relationship bc permeability to Na+ and Cl- negligible in glial cells

Skeletal Muscles

Striated (not to be confused w/ cardiac or smooth muscles) Move bones around joints: flexion or extension or both

or different?

The visual receptive fields of LGN neurons are almost identical to those of the ganglion cells that feed them. Magnocellular LGN neurons have relatively large center-surround receptive fields, respond to stimulation of their receptive field centers with a transient burst of action potentials, and are insensitive to differences in wavelength. All in all, they are just like M-type ganglion cells. Likewise, parvocellular LGN cells, like P-type retinal ganglion cells, have relatively small center-surround receptive fields and respond to stimulation of their receptive field centers with a sustained increase in the frequency of action potentials; many of them exhibit color opponency.

center-surround organization of RGC

There is a circular area of retina providing direct photoreceptor input, the receptive field center, and a surrounding area of retina providing input via horizontal cells, the receptive field surround. The response of the cell's membrane potential to light in the receptive field is opposite to that of light in the surround. Receive input from the corresponding type of bipolar cell

CA+ role in LTP

There is a large and fast rise

Ca+ role in LTD

There is a small and slow rise

How does the presynaptic terminal get rid of excess Ca2+ to make sure that vesicles are not spontaneously released (i.e., released in the absence of action potentials) at too high of a rate?

There is an ATP-dependent calcium pump and It is active even at low internal [Ca2+]

Incremental Learning

There is much better remapping if prisms of increasing strength are fit successively than if a full-strength one was fit all at once

Incremental learning

There is much more remapping if prisms of increasing strength are fit successively than if full-strength ones fit all at once

Glycine and GABA

These are inhibitory neurotransmitters

What do axons expressing the Robo receptor do?

They are repelled by slit

What is Sperry's view of our education system as it relates to the two hemispheres?

Too left hemisphere based with virtually no training in perceptual/mechanical/ spatial methods of apprehension and reasoning

What controls development? List 3 alternatives

Top Down Control (like air traffic controller) Cells "programmed" to do their parts (like robots) Bottom Up , Self Organization

What is the Jendrassek maneuver?

Top-Down Control the brain holds veto power to strengthen or weaken the reflex, consciously or unconsciously -- have the patient be kind of distracted -- clenching teeth etc.

Transgenic mouse

Transgenic models use random integration: the desired gene could end up anywhere in the host genome. The desired gene might be placed under its own (strong) promoter, leading to high levels of expression, which can be good for disease models, leading to an earlier or more robust phenotype. Transgenic animal is an animal which genome was modified by insertion of the modifying DNA (a trans-gene), DNA which stays in a trans position to the modified sequence so there is a recombination or transposition or whatever between two DNA fragments: a chromosome and inserted into cell modifying sequence of nucleic acid (lately it is not only DNA but also RNA or chimeric RNA/DNA mix).

Goldman Hodgkin-Katz (GHK) Equation

Used to calculate the membrane potential if a cell is permeable to multiple ions. Typical neuronal permeabilities at rest: PK : PNa : PCl = 1 : 0.025 : 0.45

Expression vector

Usually a plasmid or virus designed for gene expression in cells. The vector is used to introduce a specific gene into a target cell, and can commandeer the cell's mechanism for protein synthesis to produce the protein encoded by the gene.

lateral geniculate? How are they arranged?

Ventralmost layers 1 and 2 contain larger neurons (magnocellular) for motion. The four more dorsal layers small cells (parvocellular) for shape. Just ventral to each layer, numerous tiny neurons (koniocellular) for color. M-type, P-type, and nonM-nonP retinal ganglion cells thought to innervate 3 LGN cell types respectively.

M1

Very weak stimuli could give rise to large twitches only if they occurred in the _____ region (anterior to central sulcus).

Occipital Lobe

Vision

Retina

Vision (in the eye but IS part of the NS)

What is the relation between volts, amps, and ohms?

Voltage = current × resistance V = I × R 1 volt = 1 amp × 1 ohm

What is the calcium hypothesis of neurotransmission?

Voltage dependent calcium entry couples stimulation (action potential) to secretion depolarization opens voltage-gated Ca+ channel. Ca+ flows in and triggers vesicle release vesicle release proportional to calcium -- 2x Ca+ : 16x vesicle release

How does an action potential alter the membrane potential along an axon (voltage vs distance)? Compare to Voltage vs time?

Voltage vs Distance resting state straight line -> 1 dip for relative (the decline) and absolute refractory periods (starting from when it starts to incline again) -> action potential peak -> resting state straight line Voltage vs Time resting state straight line -> foot (local potentials build up) -> action potential peak -> undershoot/dip -> resting state straight line

What does the internal representation of a movement specify? What doesn't it specify?

Voluntary movements begin with an internal representation of the movement and doesn't really specify how it achieves the representation. Brain represents the outcome in a way that is independent of the specific muscles used to achieve the goal

What does CPG stand for? What is it? Where in the nervous system does the CPG for walking reside?

WHAT GENERATES PATTERN TO MAKE MOVEMENTS RHYTHMIC AND UNCONSCIOUS- RESIDES IN BRAINSTEM

growth cone collapse

WHEN A GROWTH CONE GROWING IN A CERTAIN DIRECTION GOES BACKWARD, STOP AXONS FROM GOING WHERE THEY SHOULD NOT BE

What is the crossed extensor reflex?

WHEN ONE LEG PULLED UP, OTHER STIFFENS- REFLEX ON OTHER SIDE WITHOUT FALLING OVER

Temporal Summation

When a presynaptic terminal is activated at high frequency the postsynaptic amplitude sums because each EPSP sits on the falling phase of the previous potential

Crossed-extensor reflex

When one leg pulls back, the other stiffens; interneuron crosses spinal cord and does the opposite thing on the other side

dorsal view

above angle

What is reciprocal inhibition?

a. Allows movement

What is the flexor reflex?

a. Allows you to avoid noxious stimuli

What are seven taste modalities? Which are the four "classical" ones?

a. Classical

Where is the central nervous system representation of emotion located?

a. Cortical Representation of Emotion: Limbic system: phylogenetically primitive cortex around the brainstem

.

a. Deep Brain Stimulation

How are facial muscles of expression controlled?

a. For smiles: controlled in motor areas in prefrontal cortex and ventral bsal ganglia

DBS deep brain stimilulation can treat

a. Intractable Depression

Are human facial expressions cultural or intrinsic - what is the evidence?

a. Intrinsic

What is a conditioned fear response?

a. Learn to be afraid of things that are not intrinsically scary

What is meant by "Henneman's Size Principle"?

a. Motor neurons generate muscle force by sequential recruitment to fire action potentials, beginning with the smallest/weakest and ending with the largest/strongest needed to accomplish the motor action. First motor unit you recruit is the one that has the least amount of muscle fibers.

What are the two main components of emotion? Provide an example of each

a. Physical expression (tears, blushing, crying face, fast heart beat, goose bumps). This is the physical manifestation of emotional state

What pathways are involved with each component?

a. Physical expression: Peripheral autonomic, endocrine, and motor systems by way of subcortical structures: amygdala, hypothalamus, and brainstem; maybe cingulate cortex for laughing

Why do we have emotions (2 reasons)?

a. Plays critical roles in inter and intra species communication

Three movement hierarchy

a. Reflexive ("lowest") then rhythmic (walking, breathing) then voluntary (highest): for example when you type but what makes it so complicated is once you learn how to type really well, it is as if it is a reflex

List three ways motor neuron are mapped.

a. Segmental that related to the rostrocaudal position of the muscle in the body; relates segments of the spinal cord; more motor neurons in the cervical and lumbar than in between (activate arms and legs and in between it's just back, belly, and rib)

Briefly describe the taste organs of the tongue.

a. Taste receptor cells are assembled into taste buds. Taste buds are packed together in taste papillae on the surface of the tongue. Taste receptor cells form synapses onto gustatory fibers, which project to the gustatory ganglia and then to the brain. Each papilla has multiple types of taste receptor cells and that each receptor type is specialized for a different category of taste.

3 controlers of development

a. Top-down control:, pre-programming; and Bottom-Up Self-Organization:

Name three chemical senses.

a. Visceral chemosensation

What is the crossed extensor reflex?

a. With flexor reflex on other side without falling over. enables locomotion

which of the following would not cause an increase in quantal content? a. An increase in the number of neurotransmitter molecules in a vesicle. b. An increase in number of vesicles released. c. An increase in the amount of Ca++ in the presynaptic terminal. d. A decrease in the number of voltage gated K+ channels in the presynaptic terminal.

a. an increase in the number of NT molecules in a vesicle

Neuronal plasticity

ability to alter neuronal connections due to experience

Knock-out mouse

ability to manipulate genes in mammals; instead of looking for a mutant that is lacking a gene or has a variant; method that allows investigator to mutate genes deliberately in mice

motor cortex controls movement on which side of the body? (ipsi/contralateral)

contralateral

What are the effects of axon branch changes on convergence and divergence in the developing neuromuscular system?

convergence decreases with age, - more axons innervate each target cell in younger animals - synapse elimination more target cells are innervated by each axon in younger animals - divergence decreases with age synapse elimination/pruning allows for better connectivity

Define convergence and divergence as they pertain to synaptic connections

convergence: many sensory neurons innervate a single motor neuron divergence: a single motor neuron innervates many different muslce fibers

signal transduction

converting one kind of signal or stimulus into another type

Signal transduction

converting one kind of signal or stimulus into another type (e.g. mechanical stimulus to electrical signal or electrical signal to chemical signal).

consolidation

converts short to long term memory

What two qualities of the receptor potential convey info about the nature or strength of the stimulus?

convey info in their amplitude and duration (bc. graded)

What two qualities of the action potential convey info about the nature or strength of the stimulus?

convey info in their number and timing (bc. all or none)

blockers cause (convulsions/calming)

convulsions (less chloride conductance)

Spiny neurons

cortical neurons that are excitatory (release glutamate); take information that they receive and send them to other places

Non-spiny neurons

cortical neurons that are inhibitory (release GABA)

principle neurons

migrate radially along radial glia

interneurons

migrate tangentially

double cortex

migration

Threshold

minimal membrane potential that a neuron must be depolarized to which will generate an action potential. Typically around -45 mV.

olf R cell --> glomeruli-->

mitral cell

synesthesia

mixed modality perceptions triggered by one sentence

Microglia

modified immune cells function as phagocytes removing debris from sites of damage act as scavengers

Neurotransmitter

molecule that is packaged in vesicles in the presynaptic neuron and released to bind to receptors.

monkey amygdala study

monkey had one side of brain with amygdala, brain was separated. when viewing with eye with amygdala: fear and aggression. other eye: tame

status of neuron during resting membrane potential

more Na+ outside than inside, more K+ inside than outside. Many K+ leak out, some Na+ leak in, Na+/K+ pump maintains correct concentration

why does increasing the caliber decrease membrane resistance

more caliber means more membrane means more leak channels which means less membrane resistance

What is one way in which polysynaptic connections modify the monosynaptic stretch reflex?

more connections, bigger reflex??

human facial expression

more important for emotion than body language. intrinsic--in all people. spontaneously activated paths are different than forced

what is the time consuming part of conduction

opening V-gated channels

terminal bud Depolarization

opens voltage-gated Ca2+ channels in the axon terminal

prosencephalon

optic vesicles; telencephalon vesicles, diencephalon (later forebrain)

golgi apparatus

organelle consisting of many folded membranes and vesicles that is involved in the secretion and transport of proteins

Golgi apparatus

organelle consisting of many folded membranes and vesicles that is involved in the secretion and transport of proteins.

mitochondria

organelles involved in energy production. Within a mitochondrion, the energy stored in glucose bonds is broken down to form ATP

Mitochondria

organelles involved in energy production. Within a mitochondrion, the energy stored in glucose bonds is broken down to form ATPNeurite - a neuronal process or projection that arises from the cell body, either an axon or a dendrite.

notochord

organizer gives rise to

Endoderm

organs, tract

Immediate memory

our sense of the present

what takes longer: NT diffusing across cleft or diffusing out of the cleft?

out of the cleft (1000x longer)

"neural state"

outlook -- EG change in neural state was the in class example of changing the intro to a sentence can change the way you view the sentence itself

if the action potential is bigger, there's a net

outward curret;if its more negative than the reversal potential-net inward current

Define overshoot and undershoot

overshoot = the peak of the action potential, positive/greater than zero undershoot = absolute and relative refractory periods, less than the resting potential

Sound localization in owls

owls localize sounds by differences in the time at which sounds reach their two ears; they coordinate visual and auditory space maps

What is a conditioned fear response?

pairing a neutral stimulus (e.g. a tone) and a aversive one (e.g. a foot shock) neurons that fire together strength each other

orexogenic peptides from the hypothalamus/pituitary stimulate the __ NS

parasympathetic

Undershoot

part of the action potential when the membrane potential is below the resting potential.

Overshoot

part of the action potential when the membrane potential is greater than 0 mV.

Describe alien hand syndrome

parts that have a mind of their own and become autonomous and uncontrollable in action sometimes associated with absence of callosal connections and is reminiscent of mischief

What is a phantom limb? What is a treatment that minimizes it? Why does it work?

parts that won't go away Mirror box therapy - allows the patient to see the phantom limb and perhaps replace old memories with updates via reconsolidation

method to measure single channel current

patch clamp method

axon terminal

specialized endings of the axon that makes synaptic contacts with other cells (often with dendrites/spines)

connexon

specialized membrane proteins that connect two cells at gap junctions

procedural memory

skills and learned reactions that are typically retrieved

Ectoderm

skin

If a second substhreshold EPSP arrives during the falling phase of a prior subthreshold EPSP, the total amplitude may be _______ (much greater than/exactly equal to/slightly less than) adding the peak amplitudes of each EPSP

slightly less than

Robo

slit receptor

NMDA: fast or slow rise

slow rise and decay

ribosome

small organelle responsible for assembling protein from amino acids according to the mRNA sequence (code) in a process known as translation

dendritic spinens

small protrusion on a dendrite of some neurons that receive a synaptic connection from axon terminals and compartmentalizes the chemical and electrical signals

axon terminal

specialized endings of the axon that makes synaptic contacts with other cells

Synaptic depression

smaller synaptic potentials with repetitive stimulation due to decreased quantal content - depletion of readily releasable vesicles in the nerve terminal

What is alpha bungarotoxin, what does it do, and why is it called a toxin?

snake venom component blocks the acetylcholine receptors (AChR)

tetrodotoxin blocks _______ channels form the ______

sodium; outside

CO2

some "sour" taste cells have the enzyme carbonic anhydrase, which catalyzes the reaction: CO2 + H2O <-> H+ + HCO3 H+ activates sour

how are neurotransmitters removed from synapse

some by diffusion. Enzymes break down neurotransmitters. Some presynaptic membranes contain pumps that pump back in neurotransmitters.Astrocyte endfeet.

What is the relationship between sour taste and the taste of carbonation?

some sour taste cells have an enzyme called carbonic anhydrase on their surface which catalyzes a reaction that produces H+. The produced H+ then activate the sour receptor same as before

positive feedback in an AP

something depolarizes, increases conductance of Na, which depolarizes cell

7 emotion mnemonic

something like HAS F**** CDS

dorsal ventral patterning

sonic hedgehog in spinal cord

Synaptic cleft

space between the pre- and postsynaptic neurons at a chemical synapse. Approximately 20 nm.

nodes of Ranvier

spaces between myelin with voltage-gated ion channels to help push the signal along. Positive ions gather here to balance out negative ions.

Taste Receptors

there are 5 different types of taste receptors that are perceived as one of the five taste categories (salty, sour, sweet, bitter and umami). Salty and sour receptors are ion selective channels for Na+ (salty) or H+ (sour). Sweet, amino acids (umami), and bitter are sensed by GPCRs.

How do impermeable anions inside a cell and ion selective K+ channels lead to a resting membrane potential? is it negative or positive in the cell's interior?

there are impermeant anions in the cytosol (mainly big, negative proteins) and a lot of cation channels open "at rest" -- K+ leak channels that cause the resting membrane potential to be more negative - closer to potential of K+ than for Cl-

why are there random "blips"

there is residual calcium: will still twista dn bind to SNAREs, leading to a random exocytosis event (which is a mEPP)

In what ways are glia different from neurons?

they are proliferative (glial scars), inexcitable, and there are only a few (3) types

What's wrong with Golgi stains?

they are sparse

How do TTX and lidocaine affect the function of the nervous system?

they are varieties of Na+ channel blockers TTX - puffer fish, block Na+ entry into pore from outside Lidocaine - blocks Na+ entry into pore from inside

how do blockers work?

they decrease GABA or glycines ability to increase gcl (dont inhibit --> lead to contraction results)

Why do we have emotions?

they drive us interspecies communication allows us to formulate a valence for our memories

Cerebrum

thought processes and movement