NSCI 175 Final Exam Learning Objectives

Ketamine

"special K" or "vitamin K"; blocks NMDA receptors; may be helpful in relieving depression

Explain why action potentials move away from the cell body

Action potentials cannot be generated in the cell body or dendrites spike initiation zone - the part of the neuron where an axon originates from the soma, the axon hillock - the depolarization of dendrites and soma is typically caused by synaptic input from other neurons leads to the generation of action potentials if the membrane of the axon hillock is depolarized beyond threshold

Describe the functional differences between the dorsal and ventral roots of the spinal cord

Dorsal: info into the spinal cord Ventral: info out of the spinal cord

Compare and contrast Ketamine/Esketamine and previous pharmacological treatments (MAOIs, TCAs, SSRIs, etc.)

Ketamine: antagonists on NMDA receptors Pharmacological treatments such as MAOIs, SSRIs: inhibit the reuptake of neurotransmitters

Retinofugal Pathway Damage

Lesion in left optic nerve causes blindness in left eye. Lesions is left optic tract would lead to blindness in the right visual field of both eyes

Examine how lesions of the hippocampus affect spatial memory

Lesions to a rats brain destroyed spatial memory for how to reach food. The rat never remember which arms they've already visited. Morris water maze - a rat placed in the water the first time will swim around until it bumps into the hidden platform, and then it will climb onto it - normal rats quickly learn the spatial location for the platform and on subsequent trials waste no times swimming straight to it. - rats with bilateral hippocampal damage never seem to figure out the game or remember the location of the platform

compare and contrast taste buds vs papillae

Papillae are small projections on the tongue. A tastebud is a cluster of cells, and many are found in one papilla

Lithium

• prevents the normal turnover of PIP2, an precursor for an important 2nd messenger molecules that are generated in response to activation of some G-protein-coupled neurotransmitter receptors • interferes with the actions of adenyl cyclase, essential for the generation of the second messenger cAMP, and glycogen synthase kinase, a critical enzyme in cellular energy metabolism

Describe three ways that pain is regulated

afferent regulation: pain can reduced by simultaneous activity in low-threshold mechanoreceptors (rubbing skin when its bruised) descending regulation: an abundance of opioid receptors in the periawualductal grey (PAG) of the midbrain; the PAG projects to the rostral ventromedial medulla (RVM); Opioids at the level of the PAG or the RVM can inhibit ascending nociceptive transmission Opioids: opioid receptors are G protein coupled receptors; Gi-signaling cascades and inhibit cAMP activity within the cell - 3 types of opioid receptors: Mu, Kappa, Delta - work at the level of the CNS and not the site of injury - directly inhibit the release of substance P and can trigger descending inhibition from the PAG to disinhibit GABAergic interneurons in the spinal co

Afferent vs Efferent

afferent: toward a structure efferent: away from a structure

Explain how movements are planned by the brain

highest level: strategy; the goal of the movement and the movement strategy that best achieves the goal; neocortex and basal ganglia middle level: tactics; the sequences of muscle contraction, arranged in space and time, required to smoothly and accurately achieve the strategic goal; motor cortex and cerebellum lowest level: execution; activation of the motor neuron and interneuron pools that generate the goal-directed movement and make any necessary adjustments of posture; brain stem and spinal cord

Explain how simple & complicated tastes are represented using population coding functions

population coding - the responses of.a large number of broadly tuned neurons are used to specify the properties of a particular stimulus

Compare primary sensory neurons, motor neurons, and interneurons

primary sensory neurons: cells with neurites in the sensory surface of the body (skin and retina) - motor neurons: have axons that form synapses with the muscles and command movement - interneurons: most neurons; form connections with other neurons

corticospinal tract (lateral)

pyramidal motor tract responsible for contralateral voluntary fine movement...two thirds of the axons originate in areas 4 and 6 of the frontal lobe, collectively called motor cortex Crosses, or decussates at the pyramidal decussation. They control distal muscles, particularly the flexors

Compare and contrast: retinotopy and somatotopy

retinotopy: a spatial map somatotopy: a body map

Describe the process of excitation-contraction coupling

the action potential caused by the release of ACh triggers the release of Ca2+ from an organelle inside the muscle fiber, leading to the contraction of the fiber

Explain why the action potential is referred to as all-or-none

the amplitude and velocity of an action potential are independent of the intensity of the stimulus that initiated it, provided the intensity of the stimulus that initiated it, provided that the stimulus reaches the threshold

stress response

the coordinated reaction to threatening stimuli; characterized by: avoidance behavior, increased vigilance and arousal, activation of the sympathetic division of the ANS, released cortisol from the adrenal glands

Explain the concept of driving force and calculate the driving force for an ion

the difference between the real membrane potential and the equilibrium potential, which can be written as Vm - Ek

Describe the placebo effect

the effect causes people to believe that they are being effected, but the pill is a dummy pill

Describe the methods used to investigate the internal structures of the brain (CT, MRI, fMRI, PET)

• CT: generates an image by using an X-ray source that rotates around the head w/in the plane of desired section • MRI: uses info about how H+ atoms respond to a strong magnetic field PET + fMRI: detect changes in regional blood flow and brain metabolism (neurons more active demand more glucose and oxygen)

Electroconvulsive Therapy

• electrical currents are passed between two electrodes placed on the scape. Localized electrical stimulation triggers seizures discharges in the brain, but the patient is given anesthesia and muscle relaxants to prevent violent movements during treatment • can disrupt memories that occurred before the event, and can extend back as far as 6 months

amphetamine

• enhances neurotransmission at catecholamine-utilizing synapses and causes the release of dopamine • normal stimulation action bears little resemblance to schizophrenia, however bc of its addictive properties, users often risk taking more and more to satisfy their cravings

Explain why a neuron needs a resting potential

- keeps the cell at equilibrium and not continuously firing

Norepinephrine

- locus coreleus - influences sleep and wakefulness, arousal, attention, and feeding behavior - requires dopamine beta-hydroxylase for synthesis - degraded by MAO and COMT - GPCRs

Explain what kind of info is carried by the cranial nerves

- innervates the head

Serotine

- 5HT - Found primarily in the raphe region of the pons and upper brain stem - regulates sleep and wakefulness - valuable to antipsychotic drugs - synthesized by tryptophan - terminated by SERT (goes back into nerve terminals) - SSRIs: antidepressant drugs that inhibit transport of 5-HT by SERt • prozac - metabotropic receptors linked to circadian rhythms, motor behaviors, emotional states and state of mental arousal - impairment can result in depression, axniety, schizophrenia - LSD: a drug that causes hallucinations by activating multiple types of receptors - useful in treating eating disorders

B.F. Skinner's theory of personality

- Based on the assumption that many behaviors are learned responses to the environment - Behaviorism rejects the notions of underlying conflicts and the unconscious and focuses instead on observable behaviors and their control by the environment - Mental disorders may represent maladaptive behaviors that are learned

Discuss the cause of Parkinson's disease and why it is called a basal ganglia disorder

- Characterized by rigidity, muscle tremors, slow movements, difficulty initiating physical and mental activity - Immediate cause is loss of dopaminergic neurons in the substantial nigra - The loss of DA neurons to the striatum results in DECREASED inhibitory output to the globes pallid us causing increased inhibition of the thalamus - Decreased thalamic output to the cerebral cortex

Explain the problems with the idea that there is a single system for emotions

- Diversity of emotions and brain activity - Main structures involved in emotion: no one-to-one relationship between structure and function - Limbic system: use of single, discrete emotion system

Describe post-synaptic potentials

- EPSP: a graded depolarization that results from a flow of Na+ ions • caused by ACh-gated and glutamate-gated ion channels - IPSP: a graded hyperpolarization that results from a flow from Cl- • bind to GABA or Glycine receptors • shunting inhibition - the inward movement of Cl-, which is equivalent of the outward positive current flow - reduces length constant, allowing + current to flow out of the membrane instead of down the dendrite toward the spike-initiation zone

Identify and describe the cells of the retina, and discuss the pattern of their interconnections

- horizontal cells: receive input directly from photoreceptors, inhibit bipolar cells to further refine info in visual system - Amacrine cells: receive info from bipolar cells, synapse onto other bipolar cells or ganglion cells - Ganglion cell axons join to form the optic nerve where info is sent to the lateral geniculate nucleus of the thalamus - only ones able to fire action potentials in eye

Discuss how the activity of modulatory systems changes with wakefulness, non-REM sleep, and REM sleep

- Hypocretin, a small peptide neurotransmitter expressed in the LH, strongly excite cells of the cholinergic, noradrenergic, serotonin, dopaminergic, and histaminergic modulatory systems. - promotes wakefulness, inhibits rem sleep, facilitates neurons that enhance certain kinds of motor behavior, and is involved in the regulation of neuroendocrine and autonomic systems. - thalamic neurons at rest have a tendency to generate slow, delta frequency rhythms of bursting. Under the influence of ACh, NE, and histamine, neurons depolarize and switch to more excitable single-spring mode - a general decrease in modulatory neurons firing when falling asleep - firing rates of upper brain stem, locus coeruleus, and raphe nuclei decrease to almost nothing before the onset of REM, however ACh increases during REM

Sigmund Freud's theory of psychoanalysis

- Much of mental life is unconscious - past experiences, particularly in childhood, shape how a person will feel and respond to life

Obsessive-Compulsive Disorders

- People w/ OCD have obsessions, which are recurrent, intrusive thoughts, images, ideas, or impulses that the person perceives as being inappropriate, grotesque, or forbidden - These thoughts are recognized by the affected individual for being foreign, and they evoke considerable anxiety. - They also have compulsions, which are repetitive behaviors or mental acts that are performed to reduce the anxiety associated with the obsessions

Describe the unconventional neurotransmitters, endocannabinoids, in terms of anatomy, function, receptors, and drugs targeting the systems

- THC: tetrahydrocannabinol - cannabinoid receptors are most dense in parts of the brain influence pleasure, memory, thinking, concentration sensory and time perception, and coordinated movement - arachidonoyl ethanolamide (AEA), aka anandamide, and 2-arachidonoylglycerol (2-AG). • They are retrograde messengers—carry information in the opposite direction from normal (i.e., postsynaptic to presynaptic).

PTSD

- Trauma refers to the psychological wounds of experiencing or witnessing a shocking event or events - symptoms include increased anxiety, intrusive memories, dreams or flashbacks of the traumatic experiences, irritability, and emotional numbness

Describe how a sensory event is encoded in action potentials in sensory fibers

- When a capsule on a pacinian corpuscle is compressed energy is transferred to the nerve terminal, its membrane is deformed, and mechanosensitive channels open - current flow generates an EPSP, if depolarization hits threshold, an action potential is fired

Describe the organization of the primary somatosensory cortex

- a layered structure - S1 neurons with similar inputs + responses are stacked vertically into columns that extend across the cortical layers - Broadmann's area 3b is regarded as the primary somatosensory cortex

Non-REM sleep

- a period of rest. Muscle tension throughout the body is reduced, and movement is minimal -

Describe what constitutes an EEG signal— which neurons, what kind of activity?

- an EEG measures voltages generated by the currents that flow during synaptic excitation of the dendrites of many pyramidal neurons in the cerebral cortex, which lies right under the skull and makes jo most of the brain's mass - it takes many thousands of neurons, activated together, to generate energy EEG signal big enough to be measured for all.

describe the organization and function of primary, secondary, and association cortex

- association cortex: areas in the frontal and temporal lobes (emergence of mind) - primary cortex: the areas first to receive signals from the ascending sensory pathways - secondary cortex - have heavy interconnections w/ the primary sensory areas

Identify the characteristic(s) that all anxiety disorders share

- at least 6 months of excess anxiety and worry caused by an unknown stimulus, social situations, or a fear object - Panic disorder, agoraphobia, generalized anxiety disorder, specific phobias, social phobia, PTSD, OCD

spinothalamic pahtway

- axons of the second-order neurons immediately decussate and ascend through the spinothalamic tract running along the ventral surface of the spinothalamic fibers project up the spinal cord and through the medulla, pons, and midbrain without synapsing, until they reach the thalamus - as axons travel through the brain stem, they eventually come to lie along side the medial lemniscos Spinal cord to medulla to thalamus, to primary somatosensory cortex

Define LTP and discuss the properties and mechanisms of LTP in CA1

- brief, high frequency electrical stimulation of the perforant path synapses on the neurons of the diéntate gyrus produced LTP

Explain the common mechanism that the pharmacological and non-pharmacological treatments share and describe how it relates to the glucocorticoid hypothesis

- clinically effective treatment with antidepressants dampens the hyperactivity of the HPA system and anterior cingulate cortex - Due to increased glucocorticoid receptor expresssion in the hippocampus, which occurs in response to a long-term elevation in serotonin

Explain how zeitgebers impact circadian rhythms

- environmental time cues (light/dark, temperature, and humidity variations)

Draw the pathway that olfactory information takes, from receptor to primary olfactory cortex. Identify other regions of the brain that receive olfactory information

- neurons send axons into two olfactory bulbs • input of a bulb contains about 2,00 glomeruli - each glomerus has 25,000 axons that converge + terminate on the dendrites of olfactory neurons - output axons of the olfactory bulbs course through the olfactory tracts + project directly to several targets, including the olfactory cortex

Explain how pain receptors work

- nociceptors: the free, branching unmyelinated nerve endings that signal that body tissue is being damaged - membranes contain ion channels that are activated by strong mechanical stimuli, extremes in temperatures, oxygen deprivation, and exposure to certain chemicals - the stretching or bending of the nociceotir membrane activates mechanically gated ion channels that cause the cell to depolarize and generate action potentials. Damaged cells at the site of injury can release a number if substances that cause ion channels on nociceptor membranes to open (kininogdn, bradykinin) - substance p: a peptide synthesized by the nociceptors themselves. Causes swelling of the blood capillaries and the release of histamine. - TRPv1: receptor responds to mechanosensory pain, capsaicin activates the receptor - Pain fibers release glutamate and substance P (which can boost the pain signal)

Describe pain pathways

- only free nerve endings - slow - think lightly myelinated A delta fibers and unmyelinated c fibers - spinothalamic pathways

Imagine that you want to reduce how many action potentials a given neuron can fire - propose a way to do this

- optogenetics - increase the threshold needed to fire action potentials

Describe the functional properties of the sodium channel

- patch clamp - entails sealing the tip of an electrode to a very small patch of neuronal membrane; this patch can then be torn away from the neuron, and the ionic currents across it can be measured as the membrane potential is clamped at any value the experimental selects - open with little delay - stay open for about 1 msec then inactivate - cannot be reopened by depolarization until the membrane potential returns to a negative value near threshold

Describe the experimental evidence that supports the SCN as a biological clock

- removal of the SCN abolishes the circadian rhythm of physical activity, sleeping and waking, and feeding and drinking. - In hamsters, the transplantation of a new SCN can restore rhythms within 2-4 weeks. - The brain's internal rhythms never return without an SCN. Lesions do not abolish sleeping however

Compare the two main theories of memory consolidation

- standard model of memory consolidation: information comes through neocortex areas associated with sensory systems and is then sent to the medial temporal line for processing. - changes in synapses create a memory trace via synaptic consolidation. Afterward, systems consolidation occurs in which engrams are moved gradually ove time into distributed areas of the neocortex. - multiple trace model consolidation: engrams involve neocortex, but even old memories involve the hippocampus. The term multiple trace refers to the way the model alllws for retrograde amnesia resulting from hippocampal damage to sometimes be graded in time. - each time an episodic memory is retrieved, it occurs in a context different from the initial experience and the recalled information combines with new sensory input to form a new memory trace involving both the hippocampus and neocortex.

Discuss the memory functions of the hippocampal systems

- the hippocampus appears to play a critical role in binding sensory info for the purpose of memory consolidation - a lot of research, particularly in rodents, has shown that the hippocampus supports spatial memory of the location of objects of behavioral importance - the hippocampus is involved in the storage of memories for some length of time, though the time duration is controversial

Describe how the resting membrane potential is maintained

- there is more K+ inside and Na+ ions / Cl- ions outside - Nernst equation: Eion = 2.303 RT/zF log (ion o / ion i) - ionic driving force - the difference between the real membrane potential and the equilibrium potential (Vm-Eion)

Summarize the role of the hypothalamus in aggression by citing key experimental breakthroughs

1. Animals that were not easy to provoke prior to cererbral hemisphere surgery would go into a state of violent rage w/ the least provocation after surgery a. Sham rage - animal demonstrates all the behavioral manifestations of rage but in a situation that normally would not cause anger 2. Some stimulus of the hypothalamus would cause an animal to sniff, pant, eat, or express behaviors characteristic of fear or anger John Flynn found that affective aggression and predatory aggression can be elicited by stimulating different areas of a cat's hypothalamus. - the medial hypothalamus: threat attack (arch, spit, hiss) - lateral hypothalamus: predatory aggression/silent biting (on edge, quiet attack)

Describe the molecular basis of muscle contraction

1. Ca2+ binds to troponin 2. Tropomyosin shifts position and myosin binding sites on actin are exposed 3. myosin heads bind to actin 4. myosin heads pivot 5. an atp binds to each myosin head and it disengages from action 6. the cycle continues as long as calcium and ATP are present

Stages of Sleep

1. Fleeting, usually lasting only a few minutes...lightest stage of sleep 2. Slightly deeper and may last 5-15 minutes. Includes 8-14 Hz oscillation of the EEG called sleep spindles, as well as K complex waves 3. The EEG begins large amplitude, slow delta waves, eye and body movements are few 4. The deepest stage of sleep, with large EDG rhythms of 2 Hz or less

Describe the somatosensory pathway to the brain

1. Information enters the spinal cord up the dorsal column via large dorsal root axons 2. Medulla 3. Thalamus (VPN) 4. Primary somatosensory cortex

Describe the four essential steps in the scientific process with examples

1. Observations: watching the world around, from introspection, or clinical cases 2. Replication: repeating the experiment on different subjections or making similar observations in different patients as many times as necessary to rule out the possibility of chance 3. Interpretation: analyzing the data; depends on the state of knowledge at the time and the scientist's preconceived notions 4. Verification: the observation is sufficiently robust that any competent scientist who precisely follows the protocols of the original observer can reproduce it; accepted as fast

Signal Transduction in Olfactory Neurons

1. Odorants bind to membrane odorant receptor proteins 2. Stimulate g-protein receptors 3. Adenylyl cyclase is activated and forms cAMP 4. cAMP binds to a cyclic nucleotide-gated cation channel 5. Open cation channels and allow influx of Na+ and Ca2+ 6. Ca2+-activated Cl- channels are open which cause current flow and membrane depolarization

Draw a diagram to help you describe each of the steps in synaptic transmission

1. The neuron synthesizes neurotransmitters in the terminal or soma... 2. Action potentials open voltage-gated calcium channels to allow calcium to enter the terminal - calcium enables exocytosis 3. neurotransmitters travel across the synapse and act at receptors on the postsynaptic neuron 4. neurotransmitters detach from receptors 5. neurotransmitters are cleared from the synapse by: reuptake; broken down by enzymes; astrocytes, diffusing away 6. presynaptic transmission is altered by autoreceptors and/or retrograde transmission

Summarize key neural mechanisms of sleep

1. The neurons most critical to the control of sleeping and waking are part of the diffuse modulatory neurotransmitter systems. 2. The brain stem modulatory neurons using norepinephrine and serotonin fire during waking and enhance the awake state; some neurons using acetylcholine enhance critical rem events mando other cholinergic neurons are active during waking 3. Diffuse modulatory systems control the rhythmic behaviors of the thalamus, which in turn controls many EEG rhythms of the cerebral cortex; slow, sleep related rhythms of the thalamus apparently block the flow of sensory info up to the cortex 4. Sleep also involved activity in descending branches of the discuss modulatory systems, such as the inhibition of motor neurons during dreaming.

Identify the criteria used to determine if a substance in the brain is a neurotransmitter and be able to determine if a substance is a neurotransmitter based on these criteria

1. the molecule must be synthesized and stored in the presynaptic neuron 2. the molecule must be released by the presynaptic axon terminal upon stimulation 3. the molecule, when experimentally applied, must produce a response in the postsynaptic cell that mimics the response produced by the release of neurotransmitter from the presynaptic neuron/ act on receptors to cause a biological effect 4. have a mechanism to terminate the effect

Use a diagram to illustrate the properties of place cells

A place field is a location that evokes the greatest cell firing

Compare the role of the sleep-promoting factors adenosine and melatonin

Adenosine: acts as a neuromodulator at synapses. Antagonist of adenosine receptors, such as caffeine and theophylline, have been used to keep people awake. The administration of adenosine increases sleep levels progressively increased during prolonged waking periods and sleep deprivation - has an inhibitory effect of diffuse modulatory systems for ACh, NE, and 5HT that tend to promote wakefulness Nitric oxide (NO): wake promoting cholinergic neurons of the brain stem express particularly high levels of the synthesizing enzyme for NO. Levels are highest during waking and rise rapidly with sleep deprivation - triggers the release of adenosine Melatonin: a hormone secreted by the pea sized pineal body... only released when the environment darkens— normally at night— and its release is inhibited by light

Describe the difference between efferent and afferent

Afferent is toward a structure. Efferent is away from a structure

Explain the differences between agonists and antagonists

An agonist is a drug that mimics the actions of naturally occurring neurotransmitters - nicotine (ionotropic): binds to and activates ACh receptors in skeletal muscles An antagonist binds to receptors and blocks the normal action of the transmitter - curare: an arrow-tip poison used by south american natives; works by binding tightly to ACh receptors on skeletal muscles and blocks ACh, preventing muscle contraction

Explain the importance of animal research in the field of neuroscience

Animals allow us to find treatments: for depression and schizophrenia; alzheimer's disease; to understand the nervous system; for pharmacological reasons

Compare the behavioral and EEG characteristics of the three functional states of the brain (awake, non-REM sleep, REM sleep)

Awake - EEG: low voltage, fast waves - sensation: vivid, externally generated - thought: logical, progressive - movement: continuous, voluntary - rapid eye movement: often Non-REM - EEG: high voltage, slow - Sensation: dull or absent - Thought: logical, repetitive - Movement: occasional, involuntary - REM: rare REM Sleep - EEG: los voltage, fast - sensation: internally generated, vivid - thought: vivid, illogical, bizarre - Movement: muscle paralysis, movement commanded by the brain but not carried out - REM: often

Discuss the circuitry in the hypothalamus (i.e. regions, neurons, and peptides) that is important for long term regulation of feeding

Arcuate Nucleus: contains ghrelin Paraventricular Nucleus: most neurons from the arcuate nucleus project to the PVN Lateral Hypothalamus: the PVN innervates the lateral hypothalamusl controls insulin secretion, alters taste responsiveness, facilitates feeding Ventromedial Hypothalamus: VMH inhibits feeding; damage increases body weight and food intake; if damaged, a rat will eat normal sized meals more frequently; increased insulin production and stomach empties faster - lipostastic hypothesis: the brain monitors the amount of body fat and acts to defend this energy store against perturbations - ob gene: a blood born hormonal signal that tells the brain that fat reserves are normal - Leptin: released by fat cells; regulates body mass by acting directly on neurons of the hypothalamus that decreases appetite and increase energy expenditure • deficiency stimulates hunger and feeding, suppresses energy expenditure, and inhibits reproductive competence

Compare basic theories of emotion with dimensional theories of emotion

Basic Emotion Theories - certain emotions are thought to be unique, indivisible experiences that innate and universal across culture - basic emotions: anger, disgust, fear, happiness, sadness Dimensional Emotion Theories - emotions, even basic emotions, can be broken down into smaller fundamental elements combined in different ways and differing amounts • valence: pleasant-unpleasant • arousal: weak emotion-strong emotion

Describe how a cell assembly could support memory

Cell assemblies are groups of simultaneously active neurons. The internal representation of the object was held in working memory as long as activity reverberated through the connections of the cell assembly. If activation of the cell assembly persisted long enough, consolidation would occur by a growth process that made the reciprocal connections more effective: neurons that fired together would wire together

Describe the gross organization of the mammalian nervous system in terms of the two divisions: the central nervous system (CNS) and the peripheral nervous system (PNS). Include a description of what each part does in terms of function

Central Nervous System - Cerebrum: splits into two hemispheres with contralateral control of the body - Cerebellum: primarily a control center for movement w/ connections to the cerebrum + spinal cord - Brain Stem: a complex nexus at fibers and cells; serves to relay info from the cerebrum to the spinal cord + cerebellum - spinal cord: major conduit of info from body to brain; communicates via spinal cords Peripheral Nervous System - somatic PNS: all spinal nerves that innervate the skin, joints, and muscles under voluntary control • axons enter via dorsal roots; cell bodies outside in clusters are dorsal root ganglia - autonomic PNS: neurons that innervate internal organs, blood vessels, and glands • visceral motor fibers command the contraction + relaxation and intestines and blood vessels, the rate of cardiac muscle contraction, and secretory function of glands

Describe the gross organization of the mammalian nervous system in terms of the two divisions: the central nervous system and the peripheral nervous system. Include a description of what each part does in terms of function

Central Nervous System - cerebrum: split into 2 hemispheres they control opposite side of the body - cerebellum: primarily a control center for movement with connections to the cerebrum and spinal cord. The left hemispheres controls the left side of the body. The right hemisphere controls the right side of the body - brain stem: a complex nerves of fibers and cells that serve to relay info from the cerebrum to the spinal cord and the cerebrum - spinal cord: major conduit of info from body to brain Peripheral - somatic PNS: all spinal nerves that inner are the skin, joints, and muscles under voluntary control - axons enter vía dorsal roots; cell bodies outside outside in clusters are dorsal root ganglia - autonomic PNS: neurons that inner age internal organs, blood vessels, and glands - axons bring info about visceral function to the CNS - visceral motor fibers command the contraction and relaxation of intestines and blood vessels, the rate of cardiac muscle contraction, and secretory function of glands

Compare how heroin, nicotine and cocaine alter dopamine signaling

Cocaine: acts on the dopaminergic and noradrenergic systems; blocks the reuptake of dopamine, norepinephrine, and serotonin; cocaine binds to the transports that clear transmitters and inhibits their function Nicotine: acts on the cholinergic system; the addition nicotine results in activation of alpha7 nAChRs on glutamatergic terminals and the densensitization of non-alpha7 nACHrs on GABAergic cells; increased glutamate and decreased GABA Heroin: acts on the opiate system; increases VTA cell firing by inhibiting the inhibitory GABA cells. This inhibition leads to increased firing and greater DA release in the NAcc

Identify structures of the limbic lobe

Cortex around the corpus callosum, the cortex on the medial surface of the temporal lobe, and the hippocampus

Glutamate

Definition: a nonessential amino acid that does not cross the blood brain barrier; precursor is glutamine Function: involved with working memory, perception, voluntary muscle contraction (dynamic info processing activities) - associated w/ epilepsy, anxiety, addiction, ischemic brain damage Receptors - AMPA receptor: ionotropic receptor that gates NA+ - Kainate receptor - ionotropic receptor that gares Na+ - NMDA receptor - specialized ionotropic receptor that gates Ca2+ and Na+ - metabotropic receptors • slower postsynaptic responses that can either excite or inhibit postsynaptic cells Drugs - kainic acid (AMPA agonist); ketamine (dissociative anaesthetic + NMDA antagonist); PCP aka angel dust (NMDA antagonist); MK-801: NMDA antagolnist - associated with stroke, schizophrenia, excitotoxicity, NMDA-R encephalitis

GABA and Glycine

Definition: inhibitory neurotransmitters; GABA is common in local circuit interneurons Drugs/Disease: benzodiazepines, barbituates, alcohol

Types of brain rhythms

Delta rhythms: slow, less than 4 Hz, are often large in amplitude, and are a hallmark of deep sleep Theta rhythms: 4-7 H, can occur during both sleeping and waking states Mu rhythms: similar in frequency to Allan rhythms but are largest over the motor and somatosensory areas Beta rhythms: 15-39 Hz Gamma rhythms: relatively fast, ranging from about 30-99 Hz, and signal an activated or attentive cortex High frequency, low amplitude rhythms are associated with alertness and waking, ir the dreaming stages of sleep. Low-frequency, high-amplitude rhythms are associated with non dreaming sleep states, certain drugged states, of the pathological condition of coma.

Determine when and why a researcher would use specific methods for studying neurotransmitter systems (neurotransmitters + receptors) including immunocytochemistry (or immunohistochemistry), in situ hybridization, Cre technology, neuropharmacological analysis (agonists, antagonists, etc), and ligand binding methods.

Discover if molecule is synthesized/stores in presynaptic neuron immunochemistry: used to anatomically localize particular molecules to particular cells - once the neurotransmitter has been purifeid, it is injected to cause antibodies to bind tightly to specific sites of the transmitter - by marking different antibodies w/ different colors, we can distinguish several types of cells In situ hybridization: used to confirm a cell synthesizes a particular protein or peptide - uses a complementary strand to mRNA - FISH: fluorescence in siute hybridization Produce a response similar to neurotransmitter: Microiontophoresis: dissolving molecules in order to gain an electrical chargel if iontophoeretic or pressure application causes electrophysiological changes that mimic effects, then it is a transmitter Studying Receptors Ligand-binding method: the technique of studying receptors using radioactively or nonradioactively labeled ligands Neuropharamcological analysis: ACh receptors (nicotinic vs muscarinic), selective antagonists (curare inhibits nicotinic receptors, atropine antagonizes at muscarinic receptors), glutamate receptors (AMPA, NMDA, Kainite)

Describe how the dopamine reward system changes with chronic drug use

Dopamine reward system is hijacked from drugs - as a drug addiction develops, the user experiences an increasing in "wanting" the drug, but no change or decrease in drug liking.

Describe the functional differences between the dorsal and ventral roots of the spinal cord

Dorsal roots: information into spinal cord Ventral roots: information out of cord spinal

Discuss how dopamine neurons are involved in reward prediction using experimental evidence (Fig 16.17)

Events that are better than expected cause dopamine neurons come to life, those that are worse than expected cause them to be inhibited; those that occur as expected cause no change in firing

Describe how vesicles fuse with the membrane

Exocytosis: vesicles fuse to the membrane at the active zone, allowing the vesicle to spill its content into the synaptic cleft - in high [Ca2+], proteins alter their conformation so the membrane + vesicle fuse together, forming a pore - this continues to expand until the membrane of the vesicle is fully incorporated into the presynaptic membrane

vestibulospinal tract

Function to keep the head balanced on the shoulders as the body moves through space and to turn the head in response to new sensory stimuli. Projects bilaterally down the spinal cord and activates the cervical spinal circuits that control neck and back muscles and thus guide head movement Projects ipsilaterally as far down the lumbar spinal cord. It helps us maintain an upright and balanced posture by facilitating extensors motor neurons of the legs.

Explain what Golgi and Cajal disagreed about

Golgi's theory claimed neurons were fused together to form a continuous reticulum, or network Cajal argued that neurites of different neurons are not continuous, but rather communicate by contact

Define homeostasis, anabolism and catabolism

Homeostasis - the processes that maintain the internal environment of the body within a narrow physiological range - the hypothalamus plays a key role in homeostasis anabolism - the assembly of macromolecules such as glycogen and triglycerides from simple precursors catabolism - the process of breaking down complex macromolecules

Propose at least one practical implication of reconsolidation

It can be used to treat patients with PTSD and anxiety. Rewriting those memories as something less threatening may be able to reduce anxiety

Deep brain stimulation

Implantation of an electrode into the brain in order to treat depression was pioneered by Helen Mayberg, a neurologist at Emory University.

Understand the difference between induction mechanisms and expression mechanisms

Induction mechanisms - CA1 neurons contain postsynaptic NMDA receptors. When glutamate binds and the membrane is depolarized, Mg 2+ is displaced and Ca2+ enters. The rise in postsynaptic [Ca2+] is linked to the induction of LTP - calcium activates two protein kinases: protein kinase C and CamKII. - CamKII causes the phosphorylation of the AMPA receptor, leading to a change in protein that increases the ionic conductance of the channel Expression mechanisms - postsynaptic dendritic spines appear to bud and form new synaptic contacts with axons.

Describe how the reward system and rewarding properties of drugs can be studied in the laboratory

Inject dopamine agonist/antagonists to observe the effects of dopamine/the lack of dopamine electrical self stimulation provides a reward the reinforces the habit to press the level - the most effective sites for self-stimulation fell along the trajectory of dopaminergic axons arising in the VTA, projecting through the LH to several forebrain regions - drugs that block dopamine receptors self-stimulation, suggesting that the brain animals were working to stimulate the release of dopamine in the brain reward centers: medial forebrain bundle (contain pathway from VTS to nucleus accumbens...mesolimbic pathway)

Compare and contrasts input specificity and cooperatively

Input specificity: only active inputs show synaptic plasticity Cooperativity: synapses must be active that the same time that the postsynaptic CA1 neuron is strongly depolarized. Synapses must be stimulated at frequencies high enough to cause temporal summation of the EPSPs,, and enough synapses must be activated simultaneously to cause significant spatial summation of EPSPs

Lateral pathways

Involved in voluntary movement of distal musculature and under direct cortical control

Explain how local anesthetics work

Local anesthetics such as Lidocaine bind to Na+ channels to prevent an action potential from firing. Smaller axons are affected more than larger axons bc their action potentials have a smaller safety margin

Define the stages of memory acquisition and memory consolidation

Memory acquisition occurs by a physical modification of the brain caused by incoming sensory if formation. Memory consolidation is the process by which some experiences are selected for permanent storage in long term memory

Describe mirror neurons in terms of when they are likely to fire

Mirror neurons fire when observing another animal make the same type of movement - represent particular motor acts, such as reaching, grasping, holding, or moving objects

Compare different levels of analysis in neuroscience research

Molecular: allows neurons to communicate, sentries that control what material enters/leaves neurons, conductors that orchestrate neuron growth, archivists of past experiences Cellular: focuses on how all these molecules work together to give neurons their special properties Systems: neurons form complex circuits that perform a common function Behavioral: how do systems work together to produce integrated behaviors Cognitive: how do these neural mechanisms result in self-awareness, imagination, language, thinking

Describe the available treatments for depression

Monoamine Inhibitors: antidepressant drugs that inhibit MAO, the enzyme that destroys catecholamines and serotonin Tricyclic Compounds: block the reuptake of norepinephrine and serotonin by transporters SSRIs: inhibit the reuptake of serotonin

Describe the biological theories of affective disorders

Monoamine hypothesis: mood is closely tied to the levels of released "monoamine" neurotransmitters— norepinephrine and/or serotonin— in the brain Diathesis stress hypothesis: the HPA axis is the main site where genetic and environmental influences coverage to cause mood disorders Anterior Cingulate Cortex Dysfunction: anterior cingulate cortex dysfunction contributes to the symptoms of major depression; this is supported by a number of findings, including studies that have shown that activity here is increased by autobiographical recall of a sad event and is decreased following successful medical treatment - increased metabolic activity in depressed patients - this region is considered to be a "node" in an extensive network of structures that include the frontal cortex, hippocampus, amygdala, and brain stem

Glia either out number or equal the number of neurons in the brain, yet neurons are the predominant focus of neuroscience textbooks. Explain why that might be the case.

Neuroscientists saw no evidence that glial cells communicated with each other.

Explain how histological procedures contributed to the advancement of neuroscience

Nissl Stain - Frank Nissl showed that a class of basic dyes would stain the nuclei of all cells as well as clumps of materials surrounding the nuclei of neurons (Nissl bodies) - This distinguishes neurons and glial cells. It allows histologists to study cytoarchitecture, or the arrangement, of neurons in different parts of the brain • this led to the realization of specialized regions Golgi Stain - soaking brain tissue in a silver chromate solution; causes a small percentage of neurons to become darkly colored - revealed neurons have two distinguishable parts: a central region w/ the cell nucleus and numerous thin tubes radiating away

Illustrate and explain his human sleep patterns change with age

Normal requirements among adults range from five to ten hours per night. The average length is 7.5 hours The sleep duration of about 68% of young adults is between 6.5 and 8.5 hours.

Describe the methods used to classify neurons

Number of Neurites - unipolar: a single neurite - bipolar: a neuron w/ two neurites Multipolar: a neuron with three or more neurites Dendrite shape and spines - stellate cells (star-shaped) - pyramidal cells (pyramid shaped) - spiny: with spines - aspinous: without spines Connections - info is delivered to nervous system via neurons w/ neurites in sensory surfaces Axon Length Gene Expression

Rubrospinal tract pathway

Originates in the red nucleus of the midbrain and decussates in the pons almost immediately, and parallel to those in the lateral column of the spinal cord. A major source of input is the region of the frontal cortex that also contributes to the corticospinal tract. In humans, most of its functions are consumed by the corticospinal tract

Tectospinal tract

Originates in the superior colliculus of the midbrain, which receives direct in our from the retina. The superior colliculus receives projections from visual cortex, as well as afferent axons carrying somatosensory and auditory info...it constructs a mao of the world around us After leaving the colliculus, the axons decussate and project close to the midline into cervicales regions of the spinal cord, where they control muscles of the neck, upper trunk, and shoulders

Describe the symptoms of depression

Pathology: characterized by a feeling of helplessness and loss of self control Major Depression • cardinal symptoms are lowed mood and decreased interest or pleasure in all activities • other symptoms include: - loss of appetite (or increase), insomnia or hypersomnia, fatigue, feelings of worthlessness and guilt, a diminished ability to concentrate, recurrent thoughts of death

Describe the symptoms of schizophrenia and classify them into their different categories

Pathology: characterized by a loss of contact with reality and disruption of thought, perception, mood, and movement Positive Symptoms: delusions, hallucinations, disorganized speech, grossly disorganized or catatonic behavior Negative Symptoms: reduced expression of emotion, poverty of speech, difficulty in initiating goal-directed behavior, and memory impairment

Population Coding vs Temporal Coding

Population coding ➝ using a combination of responses from receptor cells to distinguish and recognize different odors Temporal coding ➝ allows us to determine the quality of odors by the timing/frequency of cell firing

Describe the organization and function of the motor cortex

Precentral gyrus, stimulation of primary motor cortex produces movement, somatotopic organization and motor homonucleus...connects primarily with reticulospinal neurons that innervate proximal motor units Supplementary: planned initiation of movement...innervates distal motor units directly Premotor: motor sequences influenced by outside events

Describe how an action potential is propagated along an axon

Propagation of the action potential is similar to the propagation of a flame along the fuse - orthodromic conduction: action potentials conduct only in one direction, from the soma to the axon potential action potentials can be generated by depolarization at either end of the axon, so therefore can propagate in either direction - antidromic conduction: backward propagation

Describe the available treatments for anxiety disorders

Psychotherapy • the therapist gradually increases the exposure of the patient to the stimuli that produce anxiety, reinforcing the notion that the stimuli are not dangerous • the aim of psychotherapy is to alter connections in the brain such that the real or imagined stimuli no longer evoke the stress response Anxiolytic Drugs • medications that reduce anxiety by altering chemical synaptic transmission in the brain - benzodiazepines - SSRIs - GABA inhibitors

receptive field center vs receptive field surround

Receptive field center: a circular area of retina providing direct photoreceptors input Receptive field surround: the surrounding area of retina providing input via horizontal cells

Discuss reasons why we sleep and the consequences of sleep deprivation

Restoration: sleep allows us to rest and recover and to prepare to be awaken again. Adaptation: we sleep to keep out of trouble, to hide from predators when we are most vulnerable or from other harmful features of the environment, or the conserve energy. Depriving humans of rem sleep can impair their ability to learn a variety of tasks. Studies show an increase in duration of rem sleep after an intense learning experience. Depriving humans of non-rem sleep actually enhanced their performances

Compare the similarities and differences between cones and rods.

Rods - scotopic system - low acuity (ability to discern details about objects) - night vision - does not require much light - more abundant in periphery - high convergence - basic outlines of objects - outnumber cones 20:1 Cones - photopic system - high acuity (ability to discern details about objects) - color vision - requires a lot of light - high density in fovea - low convergence (1:1 in fovea)

Describe the serotonergic regulation of anger and aggression

Serotonin deficiency hypothesis: Aggression is inversely related to serotonergic activity 1. Agonists of 5-HT1B receptors decrease aggressiveness while antagonists of them increase aggressiveness.

Dopamine

Site: Present in many brain regions, but the major region is the corpus striatum, which receives major input from the substantia nigra and plays an essential role in the coordination of body movements Pathways: mesostriatal and mesolimbocortical Function: involved in motivation, reward, reinforcement, and movement Molecular Analysis - produced by DOPA - broken down by MAO and COMFT - Exclusively acts via GPCRs

Discuss physiological and biochemical processes that vary according to a circadian rhythm

Sleep/wake, body temperature, blood flow, urine production, hormone levels, hair growth, metabolic rate

Compare and contrast: rapidly-adapting and slowly-adapting receptors

Small rapidly adapting: meissner's corpuscle Large and rapidly adapting: pacinian corpuscle Small and slow adapting: merkel's disk Large and slow adapting: ruffini's ending

Compare and Contrast the role of the somatic and autonomic nervous system

Somatic: voluntary movement Autonomic: automatic functions

Compare and contrast spatial summation and temporal summation

Spatial summation refers to the adding together of EPSPs generated simultaneously at many different synapses on a dendrite Temporal summation is the adding together of EPSPs generated at the same synapses if they occur in rapid succession.

Explain the purpose of synaptic integration

Synaptic integration is the process by which multiple synaptic potentials combine with one post-synaptic neuron Synaptic integration can result in action potentials or a neural computation

Describe the effects of amygdala stimulation and lesions of the amygdala

The Klüver-Bucy Syndrome: monkeys w/ this have good visual perception but poor visual recognition...increased interest in sex but decreased in fear and aggression Lesions of the amygdala have the effect of flattening emotion; lesions impair the recognition of emotional expression (which emotions are affected remains controversial...though the most common is fear) stimulation can lead to increased vigilance or attention, [in cats] a combination of fear and violent aggression. in humans, stimulation lead to anxiety and far

Describe the function of each component of the neuron

The Soma - the cell body; contaisn cytosol and organelles - nucleus: contains chromosomes - rough ER: protein synthesis w/ ribosomes - smooth ER: heterogenous and performs many different functions - golgi apparatus: post-translational chemical processing of proteins Cytoskeleton - microtubules: straight, thick walled hollow pipe that consists of small tubes called tubulin • microtubule-associated proteins (MAPS) - anchor the microtubules to one another and to other parts of the neuron Microfilaments - numerous in neurites - brains of two thin strands of the protein actin; important for muscle contraction Neurofilaments - exist as intermediate filaments - consists of multiple subunits wound together into a rope-like structure Axon - axon hillock:tapers away from the soma to form the initial segment of the axon - axon collaterals - axon branches that travel long distances to communicate w/ other parts of the nervous system - axon terminal/terminal bouton: the end of the axon; appears as a swollen disk - the synapse Dendrites - dendrites of a single neuron are called a dendritic tree; each branch is a dendritic branch - has many specialized proteins called receptors that detect the neurotransmitters in the synaptic cleft - dendritic spines cover the dendrites; receive some types of synaptic input

Describe how demyelination affects action potential conduction

The conduction velocity of an action potential slows down without myelination. Lack of myelination can result in weakness, lack of coordination, and impaired vision and speech Result in MS and Guillain-Barré syndrome (slowing of response time)

Explain the dendritic length constant (draw a diagram to illustrate this)

The dendritic length constant is an index of how far depolarization can spread down a dendrite or axon The longer the length constant is, the more likely the EPSPs generated at distant synapse will depolarize the membrane at the axon hillock Depends on membrane resistance and internal resistance

Define pain. Explain why it should it be viewed as a positive adaptation

The feeling, or the perception, of irritating, sore, stinging, aching, throbbing, miserable, or unbearable sensations that arise from a part of the body Without pain, you wouldn't be able to tell something is wrong-- and w/o that ability, you would be unable to fix it. (Ex: a paper cut could become infected, leading to more problems)

Describe the organization of retinal inputs to the LGN

The lGN receives synaptic input from the retinal ganglion cells, and most geniculate neurons project an axon to the primary visual cortex via optic radiation Right LGN receives input from the left field, the left LGN is viewed by right field (nasal retina and temporal right retina) Two ventral layers, 1 and 2, contain larger neurons, and more dorsal layers contain smaller layers - ventral layers: magnocellular: larger cell bodies, larger receptive fields, distributed evenly throughout retina, respond to movement and broad outlines of shape, not color sensitive - dorsal layers: parvocellular: smaller receptive fields, responsible for detailed analysis of stationary objects (shape, depth, texture, color), dense in fovea, - konio cellular LGN layers: numerous tiny neurons that lie central to each layer; small cell bodies, variable receptive fields, found throughout retina, color sensitivity and function varies

Describe what happens to the membrane potential when the brain is deprived of oxygen

The membrane potential is disrupted due to a lack of ATP to drive ion movement.

Benzodiazepines

The most common group of anxiolytic drugs, which includes Valium and Xanax.

Why is it difficult to determine the ratio of neurons to glia?

There are no studies on the ratio. Cell counting takes quite a long time, however there is an emerging method. There is compelling evidence for a 1:1 ratio.

Describe the procedure for producing learned fear

Through socialization or painful experiences, we all learn to avoid certain behaviors for fear of being hurt - CER (conditioned emotional response): produced by neutral stimulus that has been paired with an emotion-producing stimulus

Compare and contrast wanting and liking

Wanting - motivation...seeking out behaviors Liking - pleasure, enjoyable...you can like something without seeking it

Compare and contrast NMJ transmission with synaptic transmission between two neurons.

What's similar? Presynaptic side is identical; both have postsynaptic receptors in order to have an effect from ACh What's different? Calcium influx on postsynaptic side; NMJ only needs needs one end-plate potential to have an action potential

psychiatry

a branch of medicine concerned with the diagnosis and treatment of disorders that affect the mind, or psyche

mania

a distinct period of abnormally and persistently elevated, expansive, or irritable mood

anxiety

a generalized response to an unknown threat or internal conflict, whereas fear is focused on known external danger

glutamate

a major excitatory neurotransmitter; NMDA receptors are a subtype of glutamate receptors

psychiatric disorder

a mental or behavioral disorder pattern that causes suffering or an impaired ability to function which is not a developmental disability

diathesis

a predisposition to a disease

hypothalamic-pituitary-adrenal (HPA) axis

a. CRH is released into the blood of the portal circulation of parvocellular neurosecretory neurons in the paraventricular nucleus of the hypothalamus b. ACTH is released by the anterior pituitary gland in response to corticotropin-releasing hormone (CRH). c. Cortisol is released from the adrenal cortex in response to an elevation in the blood level of adrenocorticotropic hormone (ACTH)

Serotonin Selective Reuptake Inhibitors

a. Highly effective in treating other disorders, most notably OCD b. Serotonin is released by a diffuse modulatory system originating in the raphe nuclei of the brain stem c. Actions of serotonin are mediated by G-protein-coupled receptors and are terminated by reuptake, via serotonin transporter proteins, in the axon terminal d. SSRIs act to prolong the actions of released serotonin at their receptors by inhibiting reuptake e. Actions are not immediate (in contrast to benzodiazepines)

Regulation of the HPA Axis

a. The amygdala is critical to fear responses i. Sensory info enters the basolateral amygdala, where it is processed and relayed to neurons in the central nucleus ii. When the central nucleus of the amygdala becomes active, the stress response ensues iii. Inappropriate activation of the amygdala has been associated with some anxiety disorders b. Downstream from the amygdala is a collection of neurons called the bed nucleus of the stria terminalis i. These neurons activate the HPA axis and the stress response c. Hippocampal activation suppresses, rather than stimulates, CRH release. i. The hippocampus contains numerous glucocorticoid receptors that respond to the cortisol released from the adrenal gland in response to HPA system activation ii. The hippocampus normally participates in the feedback regulation of the HPA axis by inhibiting CRH release (and the subsequent release of ACTH and cortisol) when circulating cortisol levels get too high iii. Continuous exposure can cause hippocampal neurons to wither and die in experimental animals

conventional neuroleptics

act as D2 receptors

Explain how the conduction velocity of a neuron varies with axonal diameter

action potential conduction velocity increases with increasing axonal diameter the fewer the pores, the fast the axon

GABA

an inhibitory neurotransmitter in the brain a. GABAA receptors are GABA-gated chloride channels that mediate fast inhibitory postsynaptic potentials b. The proper action of GABA is critical to the proper functioning of the brain: too much inhibition results in coma, too little results in seizures c. In addition to its GABA-binding site, the GABAA receptor contains sites where chemicals can act to powerfully modulate channel function d. Benzodiazepines bind to one of these sites and act to make GABA much more effective in opening the channel and produce inhibition.

PCP

angel dust; causes hallucinations and paranoia

anterior cingulate cortex dysfunction hypothesis

anterior cingulate cortex dysfunction contributes to the symptoms of major depression; this is supported by a number of findings, including studies that have shown that activity here is increased by autobiographical recall of a sad event and is decreased following successful medical treatment

Agoraphobia

anxiety about, or the avoidance of, places or situations from which escape might be difficult or embarrassing, or in which help may not be available in the event of panic attack

Describe the main types of glial cells, including the main function of each

astrocytes: regulates chemical content of extracellular space, envelops synaptic junction in the brain, restricting the spread of neurotransmitter molecules that have been released; contain special proteins that actively remove many neurotransmitters from the synaptic cleft Oligodendrocytes: provides myelin to multiple axons at a time in the CNS Schwaan cells: provides to myelin to one axon at a time in PNS Ependymal cells: fluid filled ventricles that play a role in directing cell migration during brain development Microglia: function as phagocytes to remove debris left by dead or degenerating neurons and glia Radial Glia: involved neurogenesis and neurodevelopment; movement of neurons in the brain Satellite Cells: found in the PNS; support and protect neurons; regulate neural environment

generalized anxiety disorder

at least 6 months of persistent and excessive anxiety and worry

Explain the characteristics of receptive fields in the striate cortex o Describe the main differences between simple and complex cortical cells o Describe the hierarchy of receptive fields in the visual system

binocularity - binocular receptive fields: two receptive fields, one in the ipsilateral eye + one in the cotnralateral eye - orientation selectivity: neurons in V1 respond best to an elongated bar of light moving across their receptive fields, but orientation is critical • best response is given to a bar w/ a particular orientation simple cells: receptive fields with a fixed inhibitory and excitatory zones; bar or edge shaped receptive fields; more simple cells respond to vertical or horizontal orientations than diagonal complex cells: does not respond to the exact location of a stimulus, but the pattern of light in a particular orientation anywhere within its large receptive field; responds most strongly to a moving stimulus; located in the V1 and V2

Explain the reductionist approach

breaking down how the brain works

Describe how cells of the cerebral cortex are organized

cells are arranged in layers parallel to the surface of brain

panic disorder

characterized by frequent panic attacks consisting of discrete periods with the sudden onset of intense apprehension, fearfulness, or terror, often associated with feelings of impending doom - symptoms include palpitations, sweating, trembling, shortness of breath, chest pain, nausea, dizziness, tingling sensations, and chills or blushing

Type II bipolar disorder

characterized by hyomania, a miler form of mania that is not associated with marked impairments in judgement or performance; always associated with episodes of major depression

Describe the available treatments for schizophrenia

chlorpromazine: a drug that reduces the symptoms of schizophrenia by blocking dopamine D2 receptors drug therapy combined with psychosocial support

specific phobias

clinically significant anxiety provoked by exposure to certain types of social or performance situations, often leading to avoidance behavior

Bipolar Disorder

consists of repeated episodes of mania, or mixed episodes of mania and depression, and therefore is also called manic depressive disorder

Acetylcholine

definition: the primary neurotransmitter secreted by efferent neurons of the CNS; cholinergic Function: motor control, memory storage, attention, REM switching, slowing heart + gland secretion PNS functions - ventral spinal cort to alpha motor neurons and skeletal muscle → activation and muscle contraction - autonomic to small muscles and glands → slow down heart rate and causes secretion CNS function - striatum → motor control - septal nucleus to hippocampus → memory storage and recall - nucleus basalis to cortex, amygdala, thalamus, brainstem → attention (cortex) , emotional memory (amygdala), REM switching (thalamus and brain stem) Receptors: - nicotinic receptor - non selective cation channels • nicotine is a stimulant that produces euphoria, relaxation, and addiction, and binds to this receptor - muscarinic receptors - metabotropic and mediate most effects of ACh

Describe the biological theories of schizophrenia

dopamine hypothesis: psychotic episodes in schizophrenia are triggered specifically by the activation of dopamine receptors - a link between the mesocorticolimbic dopamine system and schizophrenia has been main on the basis of two observations: ampethamine enhances neurotransmissiona t catecholamine-utilizing synapses and causes the release of dopamine; ampethamine's normal stimulation action bears little resemblance to schizoprhenia, but users often take more to satisfy their cravings, leading to a psychotic episode similar to schizophrenia Genes and the environment: Schizophrenia runs in families, some findings argue it is primarily a genetic disorder. Environmental stressors are known the exacerbate the course of the disorder...patients will have enlarged lateral ventricles, reduced cortical thickness, and abnormal neuronal lamination Glutamate hypothesis: the disorder reflects diminished activation of NMDA receptor - Ketamine and PCP act by inhibiting NMDA receptors

Describe the functional differences between the dorsal stream and the ventral stream

dorsal stream: the action, HOW pathway, through the parietal cortex, important for visual guided movements ventral stream: the perception, WHAT pathway, through the temporal cortex, specialized for identifying and recognizing objects

Define the following key anatomical reference terms: dorsal, ventral, rostral, caudal, mid-sagittal, horizontal, coronal, ipsilateral, contralateral, proximal, distal

dorsal: backside ventral: belly anterior: toward the rat's nose Posterior: toward the rat's tail ipsilateral: structures are on the same side of the body contralateral: opposite side of the body horizontal: splits brain into dorsal + ventral coronal: splits brain into anterior and posterior midsagittal plane: equal right + left halves

how do antidepressants work?

elevate monoamine transmitters in the brain; dampens hyperactivity of the HPA system and the anterior cingulate cortex in humans - possibly due to increase glucocorticoid receptor expression in the hippocampus, which occurs in response to a long term elevation in serotonin - prolonged treatment with SSRIs increases neurogenesis in the hippocampus

Explain the importance of the sodium-potassium pump

exchanges 3 Na+ for 2 K+ key in determining resting membrane potential and neuronal function

Describe how feeding is regulated during the phases of short-term regulation of feeding by release of intestinal peptides, insulin, and activation of sensory and hypothalamic neurons.

ghrelin: appetite stimulant - synthesized and released by endocrine cells of the stomach; reaches high levels before eating and drops off after eating - expectations of a meal influences ghrelin levels cholecystokinin (CCK): appetite suppressant - released by intestinal cells; reaches high levels after eating, especially after eating fatty foods; stimulates the vagus nerve --> hypothalamus If glucose is too low, pancreas secretes glucagon --> glucagon causes cells in liver to catabolize glycogen; fat-storage cells catabolize fatty acids --> glucose levels rise if glucose levels are too high, pancrease secretes insulin --> insulin causes cells in liver to synthesize glycogen; fat-storage cells synthesize triglycerides --> glucose levels fall •If glucose goes too low: brain cells cannot function leading to unconsciousness. •If glucose goes too high: damage to kidney, retina, peripheral nerves, cardiovascular system. i. Cephalic phase: the parasympathetic and enteric divisions of the ANS are activated, causing the secretion of saliva into your mouth and digestive juices into your stomach ii. Gastric phase: these responses grow much more intensive when chewing, swallowing, stomach filling occurs iii. Substrate phase: nutrients begin to be absorbed into the blood stream

Summarize three ways that the hypothalamus responds to sensory input to maintain homeostasis (i.e. humoral, visceromotor, & somatic motor)

humoral response: neurons respond to signals by stimulating or inhibiting the release of pituitary hormones into the bloodstream • response to excess fat, high leptin levels, activation of alpha MSH/CART neurons consists of increased secretion of TSH and ACTH visceromotor response: neurons in the hypothalamus respond to signals by adjusting the balance of sympathetic and parasympathetic outputs of the autonomic nervous system somatic motor response: neurons (particularly within the LH) respond to sensory signals by inciting an appropriate somatic motor behavioral response • decreases feeding behavior

Describe the HPA axis in terms of structure and function

hypothalamic-pituitary-adrenal axis 1. Corticotropin releasing hormone (CRH) is released into the parvocellular neurosecretory neurons in the PVN of the hypothalamus 2. ACTH is released by the anterior pituitary gland in response to CRH 3. Cortisol is released from the adrenal cortex in response to an elevation in the blood level of adrenocorticotropic hormone (ACTH)

Describe the organization and function of the posterior parietal cortex

i. Area 5 - a target of inputs from the primary somatosensory cortical areas 3,1,and 2 ii. Area 7 - a target of higher order visual cortical areas such as MT iii. The parietal lobes are extensively interconnected w/ regions in the anterior frontal lobes thought to be important for abstract thought, decision making, and anticipating the consequences of action iv. Area 8, area 6, and area 4 of the cerebral cortex are thought to play a role in generating the intention to move and converting that intention into a plan of action

Explain the concept of unconscious emotions

i. In some studies, when briefly shown an angry face followed by an expressionless face, the angry face is masked by the expressionless face (subjects only see expressionless face) ii. In other study, participants were shown an angry face with an electrical shock. Subjects exhibited altered ANS activity such as sweaty palms. 1. When the masking stimulus was reintroduced, the subjects had an autonomic response, even though they were unaware of the angry expression 2. Unconscious emotion is based off this observation

Explain retinotopy

i. an organization whereby neighboring cells in the retina feed info to neighboring places in their target structures—the LGN and V1 ii. Three important points: 1. The mapping of the visual field onto a retinotopically organized structure is often distorted because visual space is not sampled uniformly by the cells in the retina 2. A discrete point of light can activate many cells in the retina, and often many more cells in the target structure, due to the overlap of receptive fields 3. There is no visual "map". Perception is based on the brain's interpretation of distributed patterns of activity, not literal snapshots of the world

manic phase symptoms

inflated self-esteem or gradiosity, a decreased need for sleep, increased talkativeness or feelings of pressure to keep talking, flight of ideas, distractibility, increased goal-directed activity

Compare membrane resistance and internal resistance

internal resistance - the resistance to current flowing longitudinally down the dendrite (the length constant decreases as internal resistance increases) membrane resistance - the resistance to current flowing across the membrane

Ventromedial pathways

involved in the control of posture and locomotion and are under brain stem control

Compare and contrast the lateral pathways and ventromedial pathways in terms of anatomy and function

lateral pathways - involved in voluntary movement of the distal musculature and are under direct cortical control (limbs) - corticospinal tract: longest + largest CNS tract - rubrospinal tract: originates in the red nucleus of the midbrain; axons from the red nucleus decussate in the pons, and parallel those in the corticospinal tract in the lateral column of the spinal cord; a major source of input to the red nucleus is the region of frontal cortex that contributes to the corticospinal tract ventromedial pathways - involved in the control of posture and locomotion and are under brain stem control - contains four pathways that use sensory information about balance, body position, and the visual environment to reflexively maintain balance and body posture - vestibulospinal tract, tectospinal tract, pontine and medullary reticulospinal tract

Identify and describe four sensory receptors in the skin

mechanoreceptors: receptors sensitive to physical distortion such as bending or stretching - present throughout the body - monitor skin contact, pressure in the heart and blood vessels, stretching of the digestive organs and urinary bladder, and force against teeth pacinian corpuscle: lies deep in dermis; largest receptor - large receptive field - respond quickly but also quick adapting - ruffini's endings: found i both types of skin and are slightly smaller than Pacinian corpuscles meissner's corpuscles: 1/10 the size of Pacinian corpuscles and are located in the ridges of glabrous skin - small receptive fields Merkel's disk: consist of a nerve terminal and a flattened, non-neural epithelial cell - small receptive fields - slow adapting receptors - generate a more sustained response during a long stimulus

Describe how a modulator can change length constant

modulation - synapses with GPCRs that are not directly associated with ion channels, but instead modifies the effectiveness of EPSPs generated by other synapses with transmitter-gated channels - The binding of norepinephrine to the beta receptor activates a G-protein that activates an effector protein, adenylyl cyclase - adenylyl cyclase catalyzes the chemical reaction that converts ATP into cAMP (cyclic adenosine monophosphate) - 1st chemical messwge is converted by the beta receptor into a 2nd messenger (cAMP) - cAMP stimulates protein kinase, which catalyzes phosphorylation - phosphorylation changes the conformation of protein, thereby changing that protein's activity - decreases the K+ conductance increases the dendritic membrane resistance and therefore increases the length constant

Describe the factors that enable saltatory conduction to occur

myelin - fatty membrane layers provided by glial cells that cover leaky parts of the axon; facilitates current flow down the inside of the axon, increasing conduction velocity nodes of Ranvier - breaks in the myelin; concentrated with Na+ channels. The influx of Na+ rejuvenates the axon and helps to prevent it from dying out in myelinated axons, action potentials skip from node to node --> the action potential slows down at nodes of ranvier and speeds back up in the internodes

Describe the opioid peptides in terms of anatomy, function, receptors and drugs targeting the systems

narcotic analgesics - reduce pain without producing unconsciousness; create a sense of relaxation and sleep, and high doses, can lead to coma and death made in the cell soma and transported to the presynaptic terminal endorphins - peptides that could bind to opioid receptors

Describe adaptation

neural adaption is the gradual decrease over time in responsiveness of the sensory system to a constant stimulus

Explain the Neuron Doctrine

neurons communicate via contact

Describe the difference between a "tract" and a "nucleus"

nucleus - a mass of neurons tract - a collection of CNS axons having a common site of origin + a common destination

Describe the key ionic events that underlie each phase: Threshold; Rising phase; Peak; Falling phase; Afterhyperpolarization; Refractory period

rising phase - the rapid depolarization of the membrane overshoot - the part of the action potential where the inside of the neuron is positively charged with respect to the outside falling phase - the action potential is a rapid repolarization until the inside of the membrane is more negative than the resting potential undershoot/after-hyperpolarization: gradual restoration of the resting potential threshold: the point needed to fire an action potential absolute refractory period - Na+ channels inactivate when the membrane is depolarized and cannot be activated until the membrane becomes negative to deinactivate the channels relative refractory period - the membrane potential stays hyper-polarized until the voltage-gated potassium channels close

Explain the cellular mechanisms for each of the five tastes

salt: Na+ ions sour: H+ ions (acid) sweet: T1R2 + T1R3 proteins Bitter: any one of the TSR proteins (poison) Umami: T1R1 + T1R3

describe the five basic taste

salty, sweet, bitter, sour, umami

Describe each of the components of the somatic motor system

skeletal muscle - constitutes the bulk of the muscle mass of the body and functions to move bones around joints, to move the eyes within the head, to inhale and exhale, to control facial expression, and to produce speech the parts of the nervous system that control skeletal muscle

Describe how the HPA axis is regulated by the amygdala and the hippocampus

tldr: amygdala activates, hippocampus inhibits Amygdala - sensory info enters the basolateral amygdala where it is processed and sent to neurons in the central nucleus - when the central nucleus becomes activated, the stress response ensues - downstream from the amygdala are the bed nucleus of the stria terminalis, neurons that activate the HPA axis and stress response - inappropriate activation of the amygdala is associated with some anxiety disorders Hippocampus - suppresses CRH release - contains glucocorticoid receptors that respond to cortisol release from the adrenal gland - participates in negative feedback by inhibiting CRH release when circulating cortisol levels get too high - continuous exposure can cause hippocampal neurons to wither and die

Summarize and illustrate the steps in phototransduction

transduction is the process through the nervous system turns light into signals Light stimulation of the photo pigment activates G proteins which isn't run activate an effect or enzyme that changes end messengers into molecules. This causes ion channels to close and membrane ion channels to close, and membrane potential is altered Rods - light activates/bleaches rhospin ➝ transducin is stimulated ➝ phosphodiesterase (PDE) is activates ➝ PDE activity reduces cGMP level ➝ Na+ channels close, the cell membrane depolarizes Bipolar Cells - ON center: light depolarizes these cells...glutamate inhibits this cell - OFF center: light hyperpolarizes these cells Ganglion Cells - ON center: will fire more action potentials when light hits the cell - OFF center: will fire fewer action potentials when light hits its receptive field

Compare and contrast neurotransmitter-gated ion channels and g-protein-coupled receptors

transmitter-gated ion channels - lock and key mechanism - binding induces a conformational change - less selectivity G-Protein-Coupled Receptors - neurotransmitter molecules bind to receptor proteins embedded in the postsynaptic membrane - the receptor proteins activate small proteins, called G-proteins, which are free to move along the intracellular face of the postsynaptic membrane - the activated G-proteins activate effector proteins • effector proteins can be g-protein gated ion channels in the membrane or enzymes that synthesize 2nd messengers - metabotropic receptors - GPCRs that trigger widespread metabolic effects

antidepressants

tricyclic compounds, SSRIs, NE and 5-HT selective reuptake inhibitors, MAO inhibitors

Describe the medical interventions used to treat substance abuse

•Drugs for detoxification—benzodiazepines and drugs to help ease withdrawal symptoms •Agonists or partial agonist analogs of the addictive drug (replacement therapy)—partially activate the same pathways, such as methadone or nicotine patches •Antagonists to the addictive drug—block effects of the abused drug but may produce withdrawal symptoms, such as naloxone and naltrexone •Medications that alter drug metabolism—like Antabuse, which makes drinking produce unpleasant side effects •Reward-blocking medications—block positive reward effects of the abused drug but may produce a lack of all pleasurable feelings •Anticraving medications—reduce the appetite for the abused substance •Immunization—prompts the immune system to remove targeted drugs from circulation before reaching the brain •