COGS1000 - Introduction to Neuroscience 1

Hyperpolarization

membrane potential becomes more negative (coming back down after action potential to -70mV)K+ slowly moving out of the cell

Tetrodotoxin (TTX)

A toxin that blocks Na+ permeation through voltage-gated sodium channels, thereby blocking action potentials.

glioma

A tumor that arises from the brain's glial tissue.

concussion

A type of mild traumatic brain injury resulting from a blow or hit to the head that causes the brain to move rapidly back and forth inside the skull.

cone

A type of photoreceptor cell responsible for color vision that is found in the retina.

rod

A type of photoreceptor, usually found on the outer edges of the retina, that helps facilitate peripheral vision.

How does EEG work?

Allows us to measure activity of populations of neurons

adrenaline

Also called epinephrine, this hormone is secreted by the adrenal glands in response to stress and other challenges to the body. The release of adrenaline causes a number of changes throughout the body, including the metabolism of carbohydrates to supply the body's energy demands and increased arousal or alertness.

in vivo

An experimental method allowing scientists to study brain or neural function in a living organism.

white matter

Brain or spinal cord tissue consisting primarily of myelin-covered axons that extend from nerve cell bodies in the gray matter of the central nervous system.

Nodes of Ranvier

Gaps in the myelin sheath to which voltage-gated sodium channels are confined.

executive function

Higher level cognitive functions, including decision-making and judgment, involved with the control of behavior.

hemisphere

In brain science, refers to either half of the brain (left or right). The two hemispheres are separated by a deep groove, or fissure, down the center. Some major, specific brain functions are located in one or the other hemisphere. While popular culture suggests that "hemispheric dominance," or which side of the brain is more active, can help inform how an individual best learns, research does not support this idea.

Which statement best describes the electrical properties of nerve cells?

In comparison to copper wires, they are relatively poor conductors of electricity.

plasticity

In neuroscience, refers to the brain's capacity to change and adapt in response to developmental forces, learning processes, injury, or aging.

What role do enzymes play in synaptic transmission?

In other cases, enzymes break down the neurotransmitter within the synaptic cleft Then the component parts of the neurotransmitter can be sent back into the presynaptic neuron to make more neurotransmitter

Voltage-gated ion channels

Ion channels that are opened or closed in response to changes in transmembrane potential

Ligand-gated ion channels

Ion channels that respond to chemical signals rather than to the changes in membrane potential generated by ionic gradients. The term covers a large group of neurotransmitter receptors that combine receptor and ion channel functions into a single molecule.

Macroscopic currents

Ionic currents flowing through large numbers of ion channels distributed over a substantial area of membrane.

Microscopic currents

Ionic currents flowing through single ion channels.

central sulcus

The primary groove in the brain's cerebrum, which separates the frontal lobe in the front of the brain from the parietal and occipital lobes in the rear of the brain.

Depolarization

The process during the action potential when Na+ is rushing into the cell causing the interior to become more positive.

What does dorsal mean in relation to an animal that travels horizontally?

Towards the back/ above the spine of the animal

What does the directional term inferior mean?

Towards the feet

retinitis pigmentosa

hereditary, progressive disease marked by night blindness with atrophy and retinal pigment changes Apoptosis

What does dorsal mean in relation to humans when referring to the spinal cord?

Back

Blindness at optic chiasm ipsilateral

Binasal hemianopiaMedial of both eyes

Blindness at optic chiasm middle

Bitemporal hemianopiaLateral sides of both eyes

minimally conscious state

A disorder of consciousness, often caused by stroke, head injury, or loss of blood flow to the brain, in which an individual maintains partial conscious awareness, but may have great difficulty in communicating with, or understanding, other people.

concentration gradient

A difference in the concentration of a substance across a distance - High to lowand diffuse across the membrane - equilibrium

reuptake

A process by which released neurotransmitters are absorbed for subsequent re-use.

Phototransducin

AP Not for short distance Graded potential Light: hypopolariseDark: depolarise ( calcium channels open)

action potential form and nomenclature

Action potentials differ in different organisms however what was learnt in the squid axon was replicated

What is required for a coordinated AP

Active current Passive current to boost the AP along the long-distance transmission of electrical signals

Co-transporters

Active transporters that use the energy from ionic gradients to carry multiple ions across the membrane in the same direction.

Difference between active & passive current flows

Active will reach and exceed threshold Passive will not exceed threshold

Tetraethylammonium ions (TEA)

Inhibitor that blocks K+ ions without affecting the Na+ current

Ionic distributions in nerve cells

N+ is higher OUTSIDE cells than inside cells

LGN stains

Neocortex : 6 layersGolgi: every cellNissl: cell body and proximal dendritesNeigert: myelinated fibres, axons goes

A friend has taken a job in a neuroscience research lab, and is studying neurons in a freshwater snail. He has been told to calculate the equilibrium potential of K+. Which equation will he use and what other information will he need?

Nernst equation; concentration of K+ inside and outside of the cell

afferent neurons

Nerve cells that carry impulses towards the central nervous system

efferent neurons

Nerve cells that conduct impulses away from the central nervous system

Visual cortex layers

Nissl strainDendrite morphology: sends axons to extrastriate areasLGN Inputs: LGN pass to other layers, stellar neuronsInter laminar connection.Outputs: Ascending( red) descending ( green and blue)

Does EEG capture action potentials?

No, it captures post-synaptic potentials

addiction

Now commonly called substance use disorder, addiction is a mental health condition where a person's progressive and chronic use of drugs or alcohol leads to issues with personal relationships, the ability to work, and one's physical health.

What is the major factor of the permeability of a membrane to a specific ion

Number of open ion channels for that ion

retinohypothalamic pathway

Ocular domainance

chronic traumatic encephalopathy (CTE)

Once known as dementia pugilistica and thought to be confined largely to former boxers, this neurodegenerative disease, with symptoms including impulsivity, memory problems, and depression, affects the brains of individuals who have suffered repeated concussions and traumatic brain injuries.

optic nerve

One of the twelve pairs of cranial nerves in the human body, the optic nerve transmits information from the retina, at the back of the eye, to the brain.

What does the hypo and pretectum do?

Suprachiamatic nucleus: rods and cones polarised light, melanopsin depolarise lightEnvironment illumination: light reflex pupillary, restrict/ reduction diameter

SCN genes

Suprachiasmatic nucleus. Hypothalamic nucleus lying just above the optic chiasm that receives direct input from the retina; involved in the light entrainment of circadian rhythms

chronic encephalopathy syndrome (CES)

Symptoms, including memory issues, depression, and impulsive behavior, that manifest themselves after repeated brain traumas. Over time, CES can result in a diagnosis of chronic traumatic encephalopathy (CTE).

Voltage-gated

Term used to describe ion channels whose opening and closing is sensitive to membrane potential.

spinal cord

The "other half" of the central nervous system (with the brain). The spinal cord is a cable that descends from the brain stem to the lower back. It consists of an inner core of gray matter surrounded by white matter.

Describe a feature of Hodgkin and Huxleys mathematical model

The AP can be reconstructed based on the time course and amplitudes of the ionic conductances.

The experiment week 6

The N170 is a 'face sensitive' ERP (negative peak) that occurs around 170ms after stimulus onset over the occipito-temporal brain regions - N170 is larger in response to faces than to other objects but is also sensitive to face inversion (upside down faces), which significantly delays N170 onset Watch face vs human face IV: face v watch DV: Size of N170 Time of N170

What does ventral mean in relation to an animal that travels horizontally?

The abdominal region

Ion selectivity

The ability of channels to discriminate between different ions, a property of ion channels that are selectively permeable to some ions and not to others

recovery of function

The ability of the nervous system to repair or compensate for damage to the brain or nervous system after insult or injury in order to regain function. For example, after a stroke, many individuals must learn how to walk or talk again.

sono-stimulation

The activation of neural networks using ultrasound.

What does the word lateral refer to in the brain?

The parts of the brain in the cross-sectional image that are close to the sides of the brain

temporal lobes

The parts of the cerebrum that are located on either side of the head, roughly beneath the temples in humans. These areas are involved in hearing, language, memory storage, and emotion.

Overshoot phase

The peak, positive-going phase of an action potential, caused by high membrane permeability to a cation such as Na+ or Ca2+.

long term potentiation (LTP)

The persistent strengthening of a synapse with increased use, thought to underlie learning and memory.

gene expression

The process by which a gene's nucleotide sequence is transcribed into the form of RNA—often as a prelude to being translated into a protein.

rehabilitation

The process by which people can repair, recover, or compensate for functional abilities after sustaining damage to the nervous system. Rehabilitation activities may include speech, physical, or occupational therapies.

protein folding

The process by which the chain of amino acids that make up a protein assumes its functional shape. The protein clumps and tangles that occur in some neurodegenerative disorders are thought to be triggered when proteins "misfold."

Depolarization

The process during the action potential when sodium is rushing into the cell causing the interior to become more positive. It is a displacement of the cell,s membrane potential towards a less negative value

synaptic transmission

The process of nerve-to-nerve communication in the central nervous system, whereby one neuron sends a chemical signal across the synaptic cleft to another neuron.

neurogenesis

The production of new, maturing neurons by neural stem and progenitor cells. Rapid and widespread neurogenesis obviously occurs in the fetal brain in humans and other animals, but neuroscientists long believed that neurogenesis essentially does not occur in the adult human brain. However, over the past two decades, research has shown that it does in fact occur in the dentate gyrus of the hippocampus and possibly other brain regions. This "adult neurogenesis" appears to be vital for normal learning and memory, and may help protect the brain against stress and depression.

telomere

The protective cap found at the end of a chromosome. Research

Membrane conductance

The reciprocal of membrane resistance. Changes in membrane conductance result from, and are used to describe, the opening or closing of ion channels.

subgenual cortex

The region in the back of the frontal lobes, found below the corpus callosum, which has been implicated in mood states.

gyrus

The ridges on the brain's outer surface. Plural is gyri.

Rising Phase

The rising phase is caused by the opening of voltage-gated sodium channels. These ion channels are activated once the cell's membrane potential reaches threshold and open immediately. The electrochemical gradients drive sodium into the cell causing the depolarization

glia (or glial cells)

The supporting cells of the central nervous system. They may contribute to the transmission of nerve impulses and play a critical role in protecting and nourishing neurons.

nervous system

The system in the body that processes and transmits signals from the brain to the rest of the body to facilitate movement and behavior. It consists of two parts, the central nervous system, or the brain and spinal cord, and the peripheral nervous system, the nerves that branch off from the spinal cord extending throughout the rest of the body.

glymphatic system

The system that helps clear debris from the brain. During sleep, special glial cells called astrocytes form a network of conduits that allow cerebrospinal fluid to flush unwanted and unnecessary proteins out of the brain.

Inactivate (or inactivation)

The time dependant closing of ion channels in response to a stimulus, typically membrane depolarisation

Activate (or activation)

The time dependant opening of ion channels in response to a stimulus, typically membrane depolarisation

EEG is useful for...

The timing of neural processes

Synapse

The tiny, fluid-filled gap between the axon terminal of one neuron and the dendrite of another.presynaptic neuron is adjacent to a postsynaptic receptor on the target cell.

digital phenotyping

The use of data collected from personal electronic devices like smart phones to diagnose and monitor medical and psychiatric conditions.

pharmacotherapy

The use of pharmaceutical drugs for therapeutic purposes.

axon terminal

The very end of the axon, where electrochemical signals are passed through the synapse to neighboring cells by means of neurotransmitters and other neurochemicals. A collection of axons coming from, or going to, a specific brain area may be called a white matter fiber tract.

perception

The way the brain organizes, processes, and interprets sensory information to give rise to our ability to make sense of and navigate the world around us.

What does the directional term posterior mean?

Towards the back of the body or brain

What does the directional term anterior mean?

Towards the front of the body or brain

What does the directional term superior mean?

Towards the head or upper part of the body

What does the directional term rostral mean?

Towards the nose

What does the directional term caudal mean?

Towards the tail

Active transporters

Transmembrane proteins that actively move ions into or out of cells against their concentration gradients to trigger action potentials.Their source of energy may be ATP or the electrochemical gradients of various ions.

Active transporters

Transmembrane proteins that actively move ions into or out of cells against their concentration gradients. Their source of energy may be ATP or the electrochemical gradients of various ions

Active transporters

Transmembrane proteins that actively move ions into or out of cells against their concentration gradients. Their source of energy may be ATP or the electrochemical gradients of various ions.

Visceral motor system

Un: lens small Accommodated: bigger

stem cells

Undifferentiated cells that can grow into heart cells, kidney cells, or other cells of the body. Originally thought to be found only in embryos, stem cells in the brain have unexpectedly been discovered in adults. Researchers have shown on research animals that stem cells can be transplanted into various regions of the brain, where they develop into both neurons and glia.

What does the directional term rostral mean in humans?

Up towards the head

What does dorsal mean in relation to humans when referring to the brain?

Upper part of the brain

V4

Ventral occipital lobeParvocellular- small receptive field- slower conduction velocity- sustain response- sensitive to wavelength- colour ( not motion)

What is a sagittal section of the brain?

When the brain is sliced into two halves

What is synchronous neural activity?

When the information being received by neurons is the same (Harmonious) Can be easily deciphered

Hyperpolarisation

When the inside of the axon is more negative (relative to the outside) than the usual. Caused because voltage-gated potassium channels open and the electrical gradient that prevented further outward movement of potassium ions is now reversed causing more potassium ion channels to open. The outward diffusion of these potassium ions causes a temporary overshoot of the electrical gradient.

What happens when a presynaptic neuron is excited by an action potential?

When the presynaptic neuron is excited by an electrical signal called an action potential, this causes the vesicles to fuse with the presynaptic membrane and release their contents into the synaptic cleft Once they are in the synaptic cleft, neurotransmitters interact with receptors on the postsynaptic membrane They bind to these receptors and can cause an action to occur in the postsynaptic cell This action may involve increasing the likelihood that the postsynaptic cell will become activated and fire an action potential, or decreasing it

refractory period

a period of inactivity after a neuron has fired

What is the axon hillock and what is its function?

a plasma membrane at the axon hillock forms trans membrane protein barriers with actin filaments to block free diffusion of proteins from soma to axon - has no synapses - region of summation of excitatory and inhibitory activity - action potential usually generated here

voltage clamp technique

a technique that uses electronic feedback to simultaneously control the membrane potential of a cell and measure the transmembrane currents that result from the opening and closing of ion channels

oligodendrocyte

a type of glial cell that forms myelin in the central nervous system

AMD

age-related macular degeneration 10% exudative neovascular: wet (abnormal blood at macular), leak, damage photoreceptors, LIGHTBEAM TREATMENT 90% non exudative neovascular: Dry (disappear epithelium), slower, NO TREATMENT

What is myelin and what is its function?

an insulatory material that helps to prevent the signal from degrading

photopsins in cones

anomalous trichromats: SMLtrichomats: normal

Electrical properties of nerve cells

are fairly leaky and poor conductor of electricity compared to copper wires

Optic radiation

axons from the lateral geniculate nucleus that terminate in the primary visual areas of the occipital cortexSuperior retinal quadrants- superior to calcarine- Parietal lobe- barums loop ( inferior visual field)Inferior retinal quadrant- inferior to calcarine- occipital lobe- Meyers loops ( superior visual field)BOTH ANTERIOR PERIPHERAL VISION- less cortical magnification- less acuity

hyperopia

farsightedness ( can't see close)Cross too lateShort eye, thick lens, flat cornea

white matter

myelinated (fat) axons

nomenclature

naming system

myopia

nearsightedness (can't see far away)Cross too earlyLong eye, thin Len, round cornea

neurotrophic factor

nerve growth factor.

nerve cell

neuron

What is a presynaptic neuron?

neuron conducting impulses toward synapse (sends information) In the presynaptic neuron, there are chemical signals called neurotransmitters that are packaged into small sacs called vesicles Each vesicle can contain thousands of neurotransmitter molecules When the presynaptic neuron is excited by an electrical signal called an action potential, this causes the vesicles to fuse with the presynaptic membrane and release their contents into the synaptic cleft

Cellular components of the nervous system

neurons and glia

interneurons

neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs

In the phase labeled D, _______ ions are moving _______ the cell.

potassium; out of

Function of a neuron

process and transmit information

astrocyte

type of glial cell that transports water and salts from capillaries create the right kind of environment for neurons to communicate

Anat of rod and cones

Out- plasma m- ciliumIn- mitochondria- nucleus- vesicles- synaptic terminalRods- disk and cytoplasmic

bipolar cells

eye neurons that receive information from the retinal cells and distribute information to the ganglion cells Increase glutamate

dipolia

double vision

A dull probe stimulates a Pacinian corpuscle. An electrode is placed midway down the axon, and action potentials are recorded. After one second, the probe is pushed with greater force. What change will occur in the recording?

*

How does the resting membrane potential of a typical neuron compare to the equilibrium potential (calculated by the Nernst equation) for potassium?

*

Which statement best describes the action potential?

* 1. An action potential is specialized to transmit signals over only very short distances. 2.An action potential is a brief change in membrane potential from positive to negative. 3.An action potential is elicited by hyperpolarization. 4.An action potential occurs when the cell's membrane potential reaches threshold. 5.The level of depolarization is graded in proportion to the magnitude of the stimulus.

What is the Goldman equation?

- Demonstrates how the membrane potential is due to the concentration gradient and membrane conductance - Vm is dependent on the Nernst equilibrium and membrane conductance for each ion

Reticular theory

- Early theory of brain organisation- Net like arrangement of fused together elements

Techniques in neuroscience

- Electrophysiological recordings, lesion experients - Invasive - Can't be used on humans Cannot measure activity across the whole brain

What are inhibitory neurotransmitters?

- Nervous systems 'off' switches, decrease likelihood of neuron firing - Responsible for calming mind and body, induce sleep and filter unnecessary excitatory neurotransmitters

What are excitatory neurotransmitters?

- Nervous systems 'on' switches, increase likelihood of neuron 'firing' - When one binds with a postsynaptic receptor an electrical change occurs in cell membrane, results in excitatory post-synaptic potential (EPSP) → meaning post-synaptic cell more likely to fire

Why is functional brain imaging useful?

- Non-invasive - Can measure whole brain activity - Event stimulated activity

Event-Relevant Potentials (ERPs)

- electric potentials that are associated with specific events - individual EEG recordings are highly variable or noisy - by averaging brain activity across multiple presentations of the same/similar events, we end up with a highly replicable waveform - trial-averaged ERP waveforms consist of a sequence - positive and negative deflections

resting membrane potential

-70mV

diffusion spectrum imaging (DSI)

A brain imaging method that detects the movement of water in tissue to help visualize the brain's white matter. This approach typically allows better resolution than diffusion tensor imaging.

diffusion tensor imaging (DTI)

A brain imaging method that helps visualize the brain's white matter tracts by following the movement of water through tissues.

functional magnetic resonance imaging (fMRI)

A brain imaging technology, based on conventional MRI, that gathers information relating to short-term changes in oxygen consumption by cells in the brain. It typically uses this information to depict the brain areas that become more or less active—and presumably more or less involved—while a subject in the fMRI scanner performs a cognitive task.

Wernicke's area

A brain region housed in the left temporal lobe, believed to be responsible for the comprehension of speech. The region was first documented by German physician Carl Wernicke, after observing a patient with a lesion in this region who was unable to understand speech.

cerebellum

A brain structure located at the top of the brain stem that coordinates the brain's instructions for skilled, repetitive movements and helps maintain balance and posture. Research suggests the cerebellum may also play a role, along with the cerebrum, in some emotional and cognitive processes.

thalamus

A brain structure located at the top of the brain stem, the thalamus acts as a two-way relay station, sorting, processing, and directing signals from the spinal cord and midbrain structures to the cerebrum, and from the cerebrum down.

psychoactive drug

A broad term to describe a drug that acts on the brain and changes one's mental state, like elevating mood or reducing inhibitions. Psychoactive pharmaceuticals can help control the symptoms of some neurological and psychiatric disorders. Many "recreational drugs" are also psychoactive drugs.

induced pluripotent stem cell (iPSC)

A cell that has been taken from adult tissue and genetically modified to behave like an embryonic stem cell, with the ability to develop into any type of cell found in the body, including nerve cells.

hormone

A chemical released by the body's endocrine glands (including the adrenal glands), as well as by some tissues. Hormones act on receptors in other parts of the body to influence body functions or behavior.

RNA (ribonucleic acid)

A chemical similar to a single strand of DNA. The sugar is ribose, not deoxyribose, hence RNA. RNA delivers DNA's genetic message to the cytoplasm of a cell, where proteins are made.

neurotransmitter

A chemical that acts as a messenger between neurons and is released into the synaptic cleft when a nerve impulse reaches the end of an axon. Several dozen neurotransmitters have been identified in the brain so far, each with specific, often complex roles in brain function and human behavior.

opioid receptors (e.g., mu, delta, kappa)

A class of receptors found on neurons in the brain, spinal cord, and digestive tract. Opioid receptors are involved in numerous functions, including pain control, mood, digestion, and breathing.

neuroimmunology

A complex field in biomedical research, which focuses on the brain, the immune system, and their interactions. Neuroimmunology holds the potential for conquering ills as diverse as spinal cord injury, multiple sclerosis, and bodily reactions to bacteria or viruses, both naturally occurring and intentionally inflicted. In some circumstances, an abnormal neuroimmune response can damage brain tissue.

Ion channels

A complex of integral membrane proteins in a cell membrane that possesses a pore that only allows certain ions to diffuse across the cell membrane, thereby conferring selective ionic permeability

Alzheimer's disease

A debilitating form of dementia, this progressive and irreversible neurodegenerative disease results in the development of protein plaques and tangles that damages neurons and interfere with neural signaling, ultimately affecting memory and other important cognitive skills.

connectome

A detailed map of the myriad neural connections (also called fiber tracts) that make up the brain and nervous system.

cerebral palsy

A developmental disorder resulting from damage to the brain before or during birth, usually characterized by impaired muscle coordination and body movements, but can also include impaired cognition and social behavior.

brain-computer interface

A device or program that permits direct or indirect collaboration between the brain and a computer system. For example, a device that harnesses brain signals to control a screen cursor or a prosthetic limb.

persistent vegetative state

A disorder of consciousness, often following severe brain trauma, in which an individual has not even minimal conscious awareness. The condition can be transient, marking a stage in recovery, or permanent.

Patch clamping

A extraordinarily sensitive voltage clamp method for measuring the ionic currents that flow through individual ion channels by sucking a tiny patch of membrane to the hollow tip of a microelectrode.

obsessive compulsive disorder (OCD)

A form of anxiety disorder characterized by unreasonable thoughts, or obsessions, which result in compulsive, repetitive behaviors.

apoptosis

A form of programmed cell death that occurs as part of normal growth and development. However, in cases of brain disorders or disease, this natural process can be "hijacked," resulting in the unnecessary death of crucial neurons.

dominant gene

A gene that almost always results in a specific physical characteristic, for example a disease, even though the patient's genome possesses only one copy. With a dominant gene, the chance of passing on the gene (and therefore the trait or disease) to children is 50-50 in each pregnancy.

cognition

A general term that includes thinking, perceiving, recognizing, conceiving, judging, sensing, reasoning, and imagining.

Down syndrome

A genetic disorder characterized by intellectual impairment and physical abnormalities that arises from the genome having an extra copy of chromosome 21.

Fragile X syndrome

A genetic disorder that interferes with brain development, leading to learning disabilities and cognitive impairment, particularly with regards to language.

recessive

A genetic trait or disease that appears only in patients who have received two copies of a mutant gene, one from each parent.

fissure

A groove or indentation observed in the brain.

limbic system

A group of evolutionarily older brain structures that encircle the top of the brain stem. The limbic structures play complex roles in emotions, instincts, and appetitive behaviors.

basal ganglia

A group of structures below the cortex involved in motor, cognitive, and emotional functions.

melatonin

A hormone that is secreted by the pineal gland in the brain in response to the daily light-dark cycle, influencing the body's sleep-wake cycle.

animal model

A laboratory animal that—through changes in its diet, exposure to toxins, genetic changes, or other experimental manipulations—mimics specific signs or symptoms of a human disease. Many of the most promising advances in treating brain disorders have come from research on animal models.

dyslexia

A learning disorder that affects the ability to understand and produce language. It is commonly thought of as a reading disability, although it can affect other aspects of language.

axon

A long, single nerve fiber that transmits messages, via electrochemical impulses, from the body of the neuron to dendrites of other neurons, or directly to body tissues such as muscles.

brain tumor

A mass or growth of abnormal cells found in the brain. While people may commonly equate brain tumors with cancer, many tumors are benign—but their location in the brain can still interfere with normal brain function.

Goldman equation

A mathematical formula used to predict membrane potential in a cell where a membrane is permeable to multiple ions, from the concentrations of ions on opposite sides of the membrane and membrane permeabilities of ions.

biomarkers

A measurable physiological indicator of a biological state or condition. For example, amyloid plaques—as detected on amyloid PET scans—are a biomarker of Alzheimer's disease. Biomarkers can be used for both diagnostic and therapeutic purposes.

angiography

A medical imaging technique that allows clinicians to visualize the interior of blood vessels, arteries, veins, and the heart.

psychiatry

A medical specialty dealing with the diagnosis and treatment of mental disorders. Psychiatrists are physicians who can prescribe medicine and perform certain medical treatments. (Contrast with psychology)

Synaptic potentials

A membrane potential change (or a conductance change) generated by the action of a chemical transmitter agents. Synaptic potentials allow the transmission of information from one neuron to another

post-traumatic stress disorder (PTSD)

A mental disorder that develops in response to a traumatic event such as combat, sexual assault, or abuse. Symptoms can include mood disturbances, hyperarousal, memory flashbacks, sleep problems, anxiety, and depression.

deep brain stimulation

A method of treating various neuropsychiatric and neurodegenerative disorders through small, controlled electric shocks administered from a special battery-operated neurostimulation implant. The implant, sometimes called a "brain pacemaker," is placed within deep brain regions such as the globus pallidus or subthalamus.

electroencephalography (EEG)

A method that measures electrical activity in the brain using small electrodes placed on the scalp.

depression

A mood or affective disorder characterized by sadness and lack of motivation. Depression has been linked to disruptions in one or more of the brain's neurotransmitter systems, including those related to serotonin and dopamine.

glucose

A natural sugar that is carried in the blood and is the principal source of energy for the cells of the brain and body.

amyloid-beta (Aβ) protein

A naturally occurring protein in brain cells. Large, abnormal clumps of this protein form the amyloid plaques that are a physiological hallmark of Alzheimer's disease. Smaller groupings (oligomers) of Aβ seem more toxic to brain cells and are thought by many researchers to play an important role in the Alzheimer's disease process.

neuron

A nerve cell. The basic unit of the central nervous system, the neuron is responsible for the transmission of nerve impulses. Unlike any other cell in the body, a neuron consists of a central cell body as well as several threadlike "arms" called axons and dendrites, which transmit nerve impulses. Scientists estimate that there are approximately 86 billion neurons in the human brain

Action potential

A neural impulse; a brief electrical charge that travels down an axon. The action potential is generated by the movement of positively charged atoms in and out of channels in the axon's membrane.

Parkinson's disease

A neurodegenerative disorder characterized by tremor, slowed movement, and speech changes due to the death of dopamine neurons located in the substantia nigra.

Huntington's disease

A neurodegenerative disorder that causes progressive death of neurons in the brain, resulting in severe movement and cognitive problems. The disorder is caused by the mutation of a single gene—and symptoms typically present when an individual is in his or her 30's or 40's.

schizophrenia

A neurodevelopmental disorder characterized by disordered thinking, delusions, and hallucinations. It affects less than 1% of Americans.

attention deficit hyperactivity disorder (ADHD)

A neurodevelopmental disorder that affects attention systems and impulse control. While ADHD is primarily known as a pediatric disorder, it also affects adults.

autism spectrum disorder (ASD)

A neurodevelopmental disorder, with symptoms usually presenting within the first two years of life, characterized by issues of communication, personal interactions, and behavior. It is referred to as a spectrum disorder because of the variety in the type and severity of symptoms observed.

epilepsy

A neurological disorder characterized by abnormal electrical activity in the brain, leading to seizures.

Tourette's syndrome

A neurological disorder, beginning in childhood, characterized by repetitive, involuntary movements or vocalizations, called tics.

stroke

A neurological event that occurs when the blood supply to the brain is blocked, depriving the tissue of oxygen, or when there is a bleed into the brain due to the rupturing of an artery.

vagus nerve stimulation

A neuromodulation treatment that involves a small implant that electrically stimulates the vagus nerve, which runs from the brain stem to the abdomen. It is mostly used to treat epilepsy but is also being investigated as a potential treatment for depression, bipolar disorder, and Alzheimer's disease.

Tetraethylammonium (TEA)

A neurotoxin that inhibits motor neuron K+ channels so that K+ cannot flow through, resulting in the inhibition of muscle contraction

serotonin

A neurotransmitter believed to play many roles, including, but not limited to, temperature regulation, sensory perception, and the onset of sleep. Neurons using serotonin as a transmitter are found in the brain and in the gut. A number of antidepressant medications are targeted to brain serotonin systems.

gamma-aminobutyric acid (GABA)

A neurotransmitter implicated in brain development, muscle control, and reduced stress response.

dopamine

A neurotransmitter involved in motivation, learning, pleasure, the control of body movement, and other brain functions.

magnetic resonance imaging (MRI)

A non-invasive imaging technology, often used for brain imaging. An MRI scanner includes intensely powerful magnets, typically 10,000 to 40,000 times as strong as the Earth's magnetic field. These magnets, combined with coils that send electromagnetic pulses into the scanned tissue, induce radio-frequency signals from individual hydrogen atoms within the tissue. The scanner records and processes these signals to create an image of the scanned tissue. MRI scans can depict high resolution images of the entire brain, allowing clinicians to determine if the brain tissue visualized is normal, abnormal, or damaged due to a neurological disorder or trauma. MRI technology has also been adapted to measure brain activity with functional MRI methods.

transcranial electrical stimulation (tDCS and tACS)

A non-invasive procedure that applies electrical stimulation to the scalp to increase or decrease neural signaling. The two main types are direct current stimulation (tDCS) and alternating current stimulation (tACS). They are used for therapeutic purposes as well as to study cognitive processing.

transcranial magnetic stimulation (TMS)

A non-invasive procedure that uses the energy from a strong magnet to stimulate changes in neural processing from above the scalp. It is used as a treatment for depression as well as a research method to investigate cognitive processes.

sonogenetics

A novel investigative approach that turns genetically modified neurons on and off using ultrasonic waves.

neural circuits

A number of neurons that are connected by synapses - neuropilie. myotatic reflex (knee-jerk-reflex)sensory receptors - receptor potentials or synaptic potentials

occipital lobe

A part of the brain's cerebrum, located at the rear of the brain, above the cerebellum. The occipital lobe is primarily concerned with vision and encompasses the visual cortex.

critical period

A period of development during which an ability or characteristic is thought to be most easily learned or attained.

mutation

A permanent structural alteration to DNA that modifies its previous nucleotide sequence. In most cases, DNA changes either have no effect or cause harm, but occasionally a mutation improves an organism's chance of surviving and procreating.

nurture

A popular term for the influence of environmental factors on human development, such as the experiences one is exposed to in early life. The term is often used in the context of "nature versus nurture," which relates to the interplay of "nature" (genetic or inherited, predetermined influences) and environmental, or experiential, forces.

ion channel

A pore in the membrane of a neuron that allows ions to pass through, helping to shape action potentials.

What are post-synaptic potentials?

A post-synaptic potential (PSP) is a voltage change at a receptor site on a post-synaptic cell membrane

ketamine

A powerful anesthetic drug, originally manufactured for veterinary use, that has been shown to be an effective treatment for major depressive disorder, especially in patients who do not respond well to traditional antidepressant medications.

hippocampus

A primitive brain structure, located deep in the brain, that is critical for memory and learning.

brain stem

A primitive part of the brain that connects the brain to the spinal cord, the brain stem controls functions basic to survival, such as heart rate, breathing, digestive processes, and sleeping.

synaptic pruning

A process by which specialized cells called microglia eliminate unnecessary synapses as part of normal and healthy brain development.

Regenerative

A process that is self sustaining, in neuroscience, an example is an action potential, because an action potential produced at one location depolarises downstream regions, thereby activating voltage gated ion channels to generate an action potential

multiple sclerosis

A progressive neurodegenerative disease involving damage to the protective myelin sheaths of nerve cells in the brain and spinal cord. Symptoms include impaired movement, pain, and fatigue.

blood-brain barrier

A protective barrier that separates the brain from the blood circulating across the body. The blood-brain barrier is semipermeable, meaning it allows the passage of water as well as molecules like glucose and other amino acids that help promote neural function.

prion

A protein aggregate that can multiply itself, inducing the formation of new aggregates from individual copies of the protein it encounters. Prions have the potential to spread within the body and brain, and even from one organism to another—"infectiously," like a virus. The first prions described were hardy aggregates of PrP, the prion protein. They are responsible for a set of rapid, fatal, and potentially transmissible neurodegenerative diseases including Creutzfeldt-Jakob disease and bovine spongiform encephalopathy ("mad cow disease"). Many researchers now argue that protein aggregates in other neurodegenerative diseases, such as the Aβ and tau plaques of Alzheimer's, have such similar properties that they also deserve to be called prions.

enzyme

A protein that facilitates a biochemical reaction. Organisms could not function if they had no enzymes.

CRISPR (clustered regularly-interspaced short palindromic repeats)

A relatively precise and reliable DNA-editing technique.

psychosis

A severe symptom of mental illness in which a person's thoughts and perceptions are so disordered that the individual loses touch with reality.

sulcus

A shallower groove on the brain's cerebrum (deeper grooves are called fissures).

What is a horizontal/transverse section of the brain?

A slice of the brain along the long axis of the body

Receptor potentials

A slow, graded electrical change in the membrane potential elicited by receptor neurons in response to a physical stimulus/sensory transduction

subthalamic nucleus

A small brain structure, located in the basal ganglia, that plays an important role in coordinating movement. It is the most common target for neuromodulation techniques, like deep brain stimulation, to help diminish the symptoms of Parkinson's disease.

striatum

A small group of subcortical structures, including the caudate nucleus, putamen, and nucleus accumbens, located in the midbrain. These regions are implicated in both movement and reward-related behaviors.

hypothalamus

A small structure located at the base of the brain, where signals from the brain and the body's hormonal system interact.

microglia

A small, specialized glial cell that operates as the first line of immune defense in the central nervous system.

mesolimbic pathway

A specialized brain circuit implicated in the processing of risk and reward information.

nucleotide sequence

A specific and ordered array of nucleotides that make up a specific genetic variant or allele.

rapid eye movement (REM) sleep

A stage of sleep occurring approximately 90 minutes after sleep onset characterized by increased brain activity, rapid eye movements, and muscle relaxation.

astrocyte

A star-shaped glial cell that supports neurons, by helping to both feed and remove waste from the cell, and otherwise modulates the activity of the neuron. Astrocytes also play critical roles in brain development and the creation of synapses

mood

A state of mind or feeling. In neuroscience, depression and anxiety are considered mood disorders, for example.

cortisol

A steroid hormone produced by the adrenal glands that controls how the body uses fat, protein, carbohydrates, and minerals, and helps reduce inflammation. Cortisol is released in the body's stress response; scientists have found that prolonged exposure to cortisol has damaging effects on the brain.

epigenetics

A subset of genetics that focuses on how specific environmental factors can influence where, when, and how a gene is expressed, resulting in variation in the gene's related traits.

opiate

A synthetic (e.g., Demerol, Fentanyl) or plant-derived (e.g., opium, heroin, morphine) compound that binds and activates opioid receptors on certain neurons. Opiates typically but not always have pain-relieving, anxiety-reducing, and even euphoria-inducing effects, and are generally considered addictive.

narcotic

A synthetic chemical compound that mimics the action of the body's natural endorphins—hormones secreted to counteract pain. Narcotic drugs have a valid and useful role in the management of pain but may lead to physical dependence in susceptible individuals if used for long periods.

endocrine system

A system in the body composed of several different glands and organs that secrete hormones.

Voltage clamp method/ technique

A technique that uses electronic feedback to simultaneously control the membrane potential of a cell and measure the transmembrane currents that result from the opening and closing of ion channels

electroconvulsive therapy (ECT)

A therapeutic treatment for depression and other mental illnesses that sends small electric currents over the scalp to trigger a brief seizure.

chromosome

A threadlike structure of nucleotides that carries an organism's genes or genetic information.

tau protein

A type of protein abundantly found in neurons. When this protein is not adequately cleared from the brain, it can form tangles that are a key pathology of several neurodegenerative disorders including frontotemporal degeneration, CTE, and Alzheimer's disease.

amino acid

A type of small organic molecule that has a variety of biological roles but is best known as the "building block" of proteins.

neuromuscular junction

ACH Synapse between Lower motor neuron/ alpha motor neuron & Muscle fibre Calcium channels open Trigger myosin and actin interaction

amyotrophic lateral sclerosis (ALS)

Also known as Lou Gehrig's disease, this neurodegenerative disease results in the death of brain cells that control the muscles.

bipolar disorder

Also known as manic depression or manic-depressive disorder, bipolar disorder is characterized by unpredictable changes in mood, as well as energy and activity levels, that can interfere with everyday tasks.

What are the axon terminals and what is its function?

Also known as synaptic buttons When the signal reaches the axon terminals it can cause the release of neurotransmitter - sending information on to another neuron When a neurotransmitter is released from axon terminals, it interacts with receptors on the dendrites of the next neuron, and then the process repeats with the next neuron.

reward/reinforcement brain network

Also known as the mesolimbic circuit, this important network of brain regions stretching from the brain stem to the frontal lobes is implicated in risk and reward processing, as well as learning.

cell body

Also known as the soma, this central part of the neuron contains the nucleus of the neuron. The axon and dendrites connect to this part of the cell.

nerve impulse

Also referred to as a nerve signal, the way that a neuron communicates with other cells by transmitting an electrochemical signal down the length of the axon.

nerve growth factor

Also referred to as a neurotrophic factor, this special protein helps regulate the growth and survival of nerve cells. One of the most well-known of these is brain-derived neurotrophic factor (BDNF).

neuroplasticity

Also referred to as brain plasticity or neural plasticity, this is the ability of the brain to change throughout the lifespan, forming new synapses and neural connections in response to the environment.

machine learning

Also referred to as deep learning, machine learning is a type of artificial intelligence algorithm that can learn rules or identify diagnostic criteria from immense data sets of brain imaging or genetic information. These algorithms are becoming more prevalent in scientific research—and are also starting to be incorporated into translational neuroscience research and medical practice.

midbrain

Also referred to as the mesencephalon, the midbrain is a small part of the brain stem that plays an important role in movement as well as auditory and visual processing.

List all the refractive errors

Ametropia- emmetropia-myopia-hyperopia

computed tomography (CT or CAT)

An X-ray technique introduced in the early 1970s that enables scientists to take cross-sectional images of the body and brain. CT uses a series of X-ray beams passed through the body to collect information about tissue density, then applies sophisticated computer and mathematical formulas to create an anatomical image from the data.

psychology

An academic or scientific field of study concerned with the behavior of humans and animals and related mental processes. Psychologists typically have Ph.D. degrees and while able to evaluate and treat mental disorders, are rarely able to prescribe medication. (Contrast with psychiatry)

Threshold

An action potential has occurred and membrane potential reaches threshold

two-photon microscopy

An advanced microscopy technique that uses fluorescent markers to look at living tissue approximately one millimeter below the skin's surface.

Tetrodotoxin (TX)

An alkaloid neurotoxin that is found in pufferfish, tropical frogs and some types of salamanders is an inhibitor that blocks the Na+ current without affecting the K+ current

opioid

An artificially derived drug or chemical that acts on the nervous system in a similar manner to opiates, influencing the "pleasure pathways" of the dopamine system by locking on to specialized opioid receptors in certain neurons.

pituitary gland

An endocrine organ at the base of the brain that is closely linked with the hypothalamus. The pituitary gland is composed of two lobes, the anterior and posterior lobes, and secretes hormones that regulate the activity of the other endocrine organs in the body.

in vitro

An experimental method to study brain or neural function by looking at cells outside a living organism, for example, in a test tube or petri dish.

in silico

An experimental method to study brain or neural function using computer modeling or computer simulation.

Pore loop

An extracellular domain of amino acids, found in certain ion channels, that lines the channel pore and allows only certain ions to pass.

X-ray

An imaging method that uses electromagnetic radiation to visualize the structures inside the body, particularly bones.

ultrasound

An imaging technique that uses sound waves to visualize the inside of the body.

positron emission tomography (PET)

An imaging technique, often used in brain imaging. For a PET scan of the brain, a radioactive "marker" that emits, or releases, positrons (parts of an atom that release gamma radiation) is injected into the bloodstream. Detectors outside of the head can sense these "positron emissions," which are then reconstructed using sophisticated computer programs to create computer images. Since blood flow and metabolism increase in brain regions at work, those areas have higher concentrations of the marker, and researchers can see which brain regions activate during certain tasks or exposure to sensory stimuli. Ligands can be added to a PET scan to detect pathological entities such as amyloid or tau deposits.

traumatic brain injury (TBI)

An injury to the brain acquired when the head is violently shook, struck, or pierced by an object. A nearby blast or explosion, as may occur in combat, emits shock waves that can also cause a TBI. Moderate to severe TBI causes permanent impairments in brain function. Symptoms of mild TBI may include headache, dizziness, attention problems, or issues with behavior and mood.

lesion

An injury, area of disease, or surgical incision to body tissue. Much of what we know about the functions of brain structures or pathways comes from lesion mapping studies, where scientists observe the behavior of people with an injury to a distinct area of the brain or analyze the behavior of a laboratory animal resulting from a lesion made in the brain.

optogenetics

An innovative neuroscientific technique that uses light to turn genetically modified neurons on and off at will, in live animals.

neuroethics

An interdisciplinary field of study that addresses the ethical implications of our increased ability to understand and change the brain. Enhanced cognitive performance, life extension, the use of neuroscience in marketing, and many other issues are included in this ongoing social-scientific debate.

computational neuroscience

An interdisciplinary field of study that uses information processing properties and algorithms to further the study of brain function and behavior.

neuroeconomics

An interdisciplinary field of study that uses neuroscientific research to help explain human decision-making behavior.

glioblastoma

An invasive brain tumor made up of glial tissue, blood vessels, and dead neurons.

Name the axes of the nervous system (brain)

Anterior: frontPosterior: behindRostral: noseCaudal: tailCoronal: "crown"Sagittial: 'sideways"Dorsal: topVentral: bottom

How many neurons does the brain contain?

Approximately 85 billion

ions

Atoms or small groups of atoms that carry an electric charge, either positive or negative. When a nerve impulse is fired, ions flow through channels in the membrane of a nerve cell, abruptly changing the voltage across the membrane in that part of the cell. This sets off a chain reaction of similar voltage changes along the cell's axon to the synapse, where it causes the release of neurotransmitters into the synaptic cleft.

Axons and Dendrites

Axons carry signals away from the cell body(where action potentials take place)Dendrites carry signal towards cell body(Receives info/action potential from other neurons)Myelin sheath A layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next.

What is the soma and what is its function?

Cell body The signals picked up by dendrites cause electrical changes in a neuron that are interpreted The soma contains the nucleus, which contains the DNA or genetic material of the cell The soma takes all of the information from the dendrites and puts it together in an area called the axon hillock

Describe 1-2 facts about each of the following: the Central Sulcus, Precentral Gyrus and Postcentral Gyrus.

Central sulcus: A prominent sulcus on the dorsal-lateral aspect of the cerebral hemisphere formed by the precentral and postcentral gyri. Defines the boundary between the frontal and parietal lobes of the cerebral cortex. Precentral gyrus: Vertically oriented gyrus that forms the anterior bank of the central sulcus. This gyrus contains the primary motor cortex and posterior regions of the premotor cortex. Postcentral gyrus: Vertically oriented gyros that forms of the posterior bank of the central sulcus. This gyrus contains the primary somatosensory cortex.

Voltage sensor

Charged structure within a membrane spanning domain of an ion channel that confers the ability to sense changes in transmembrane potential

Synaptic transmission can occur in 2 ways?

Chemical synapses (most common) action potenial passes through neuronelectrical synapses can pass over the synapses gap

antidepressant medication

Classes of drugs that can treat depressive symptoms by affecting the levels of specific neurotransmitters in the brain. One of the most well-known types of antidepressant are selective serotonin reuptake inhibitors.

cataracts

Cornea produce refraction Loose transparency Less less refraction

gene mapping

Determining the relative positions of genes on a chromosome and the distance between them.

Broca's area

Discovered by French physician Paul Broca in the late 19th century, this small region in the left frontal lobe has been linked to speech production.

Neuron theory

Discovered that neurons were individual and not fused together as one continuous feed

neurodegenerative diseases

Diseases characterized by the progressive deterioration and death of nerve cells (neurodegeneration), typically originating in one area of the brain and spreading to other connected areas. Neurodegenerative diseases include amyotrophic lateral sclerosis (ALS), Huntington's disease, Alzheimer's disease, frontotemporal degeneration, and Parkinson's disease.

neurodevelopmental disorder

Disorders or conditions arising from impairments during the development and maturation of the brain and/or nervous system. Neurodevelopmental disorders include schizophrenia and autism spectrum disorder.

What does the directional term caudal mean in humans?

Down towards the end of the spinal cord

Nernst equation

Ecell= E°cell - (RT/nF) (lnQ)A mathematical formula that predicts the equilibrium potential generated ironically across a membrane at electrochemical equilibrium

What does EEG stand for?

Electroencephalogram (test of brain activity)

What affects the the membrane potential and equilibrium potential?

Equilibrium potential is affected by the concentration and electrical gradients of 1 ionMembrane potential is affected by gradients of all ions.

What is a dendrite and what is its function?

Extend from the left side of the neuron Look a little like tree branches The area where neurons receive most of their information There are receptors on the end of dendrites that pick up information from other neurons that come in the form of chemicals called neurotransmitters The signals picked up by dendrites cause electrical changes in a neuron that are interpreted in an area called the soma (cell body)

A D

Fall 1 retina (occipital)A:LNRD: RNR

B C

Falls on 2 retinasB: LNR RTR right hemifieldC: RNR LTR left hemifield

anxiety

Feelings of intense and persistent worry or fear regarding everyday situations. While some feelings of anxiety are normal, they can be classified as an anxiety disorder when the symptoms start to interfere with daily living.

posterior chamber

Flow to ant chamber Phagocytosis cells 80% vitreous humour

anterior chamber

Fluid replaced Maintain inteaocular pressure Drains iris and cornea

What is white matter?

Found in the deeper tissues of the brain (subcortical). Contains nerve fibres (axons) which are extensions of nerve cells (neurons) Used for communication

What does ventral mean in relation to humans when referring to the spinal cord?

Front

Brain map

Frontal lobe - problem solvingParietal lobe - Spacial awarenessOccipital lobe - Visual perceptionTemporal lobe - Memory, languageCerebellum - Coordination

Where in the brain is the frontal lobe?

Frontal part of the brain (forehead side)

dementia

General mental deterioration from a previously normal state of cognitive function due to disease or psychological factors. Alzheimer's disease is one form of dementia.

ganglion cells

Has AP

Cones

High spatial resolution Insensitive to light High acuity1 cell3 photo pigment Photopsin

Retina flipped which way

Horizontal and vertical

endorphins

Hormones produced by the brain, in response to pain or stress, to blunt the sensation of pain. Narcotic drugs, such as morphine, imitate the actions of the body's natural endorphins.

Passive electrical responses

Hyperpolarising responses applied to electrical currents that that do not require activation of voltage-gated ion channels or any unique property of neurons

occipito-temporal area

Identifies words rapidly and automatically on sight, instead of analyzing them sound by sound.

What is the axon and what is its function?

If the signal of the neurotransmitter is strong enough, it is sent to the next part of the cell, which is called the axon. At this point, the signal is called an axon potential The axon potential travels down the axon which is covered with myelin, an insulatory material that helps to prevent the signal from degrading

Which statement about the ionic permeability of cell membranes is true?

In resting nerve cells, the membrane is quite permeable to potassium.

What is reuptake in the context of synaptic transmission?

In some cases, the neurotransmitter is taken back up into the presynaptic neuron in a process called reuptake. Once back inside the presynaptic neuron, the neurotransmitter can be recycled and reused

presynaptic cell

In synaptic transmission, the neuron that sends a nerve impulse across the synaptic cleft to another neuron.

psychological dependence

In the science of addiction, psychological dependence refers to the psychological factors, including mood and motivation that help to sustain addictive behaviors (like craving a cigarette after a meal), as opposed to the physical dependence that manifests when a person attempts to stop using a particular substance (e.g., tremors, racing pulse). Brain scientists now understand that psychological factors are central to addictive disorders and are often the most difficult to treat.

What happens to an action potential when you increase the voltage?

It is reached quicker The higher the current, the earlier the AP is reached

Which statement about electrochemical equilibrium is true?

It occurs when the potential across the membrane exactly offsets the concentration gradient.

Retina L R

L: more left peripheryR: more right peripheryBoth: central regions register fovea ( disproportionate large)

ACH

Large end plate potential produced

MT

Lateral surface occipital lopeMagno cellular- large receptive field- fast conduction velocity- insensitive to wavelengths- motion ( not colour)

Blindness at optic Tracts

Left or right homonymous hemianopia

V1

Light and dark barsOrientationMotion directionSpatial frequencyTemporal TUNINGVertical columns ( vertical electrode penetration): same receptive field and orientation tuning curveAdjacent columns (oblique electrode penetration):Shifted receptive field and progressive orientation select

basilar artery

Located at the base of the skull, the basilar artery is a large, specialized blood vessel that supplies oxygenated blood to the brain and nervous system.

somatosensory cortex

Located in the parietal lobe, this region of the brain processes touch, pressure, and pain information.

adrenal glands

Located on top of each kidney, these two glands are involved in the body's response to stress and help regulate growth, blood glucose levels, and the body's metabolic rate. They receive signals from the brain and secrete several different hormones in response, including cortisol and adrenaline.

local anesthesia

Loss of sensation at the desired site of action. Block action potential by blocking the Na+ channels.

What is asynchronous neural activity?

Lots of different stimulation/information Busy

What does ventral mean in relation to humans when referring to the brain?

Lower part of the brain

Variety of information...

Luminance, spectral differences, orientation, motion

Dichromatic blindness

M L

Striate cortex

M axons: upper 4 C layer (alpha)P axons: lower 4 C layer (beta)K axons: superficial layers 2/3

Thalamus dorsal lateral geniculate nuclues

M cells: 2 ventral layersK cells: interlaminar zonesP cells: 6 dorsal layersBoth ON OFF CENTERS

retina cells

M ganglion cells- thick axons, large bodies, more dendritesK - betweenP- thin axons, small bodies, less dendrites

Name all the parts of eye

MaculaOptic disk/ papilla: no photoreceptorsOptic nerve/ pherpheryFovea: no blood vessels, has photoreceptorsRetina: NEuorns here ONLYChoroid/ middle uveal tract: contain ciliary bed and nourish retinal receptor, vascular tunicSclera: fibrous tunicLensIris: vascular tunicPupilCornea: fibrous tunicCiliary musclesZonule diverse

Saltatory (or saltatory conduction)

Mechanism of the action potential propagation in myelinated axons; so named because action potentials 'jump' from one node of Ranvier to the next due to generation of action potentials only at these sites

ATPase pumps

Membrane pumps that use the hydrolysis of ATP to translocate ions against their electrochemical gradients.

Ion exchangers

Membrane transporters that exchange intracellular and extracellular ions against their concentration gradient by using the electrochemical gradient of other ions as an energy source.

Isometric vs Isotonic

Metric: muscle isolated Tonic: nothing isolated

receptors

Molecules on the surfaces of neurons whose structures precisely match those of chemical messengers (such as neurotransmitters or hormones) released during synaptic transmission. The chemicals attach themselves to the receptors, in lock-and-key fashion, to activate the receiving cell structure.

Blindness at optic nerve

Monocular blindnessOne whole eye

temporal visual field

Monocular portion of visual fieldFlipped upside downVisual field to retina fieldLeft right

What is a synapse and what is its function?

Most communication between neurons occurs at a specialized structure called a synapse A synapse is an area where two neurons come close enough to one another that they are able to pass chemical signals from one cell to another The neurons are not actually connected but are separated by a microscopically small space called a synaptic cleft

vagus nerve

One of the twelve pairs of cranial nerves in the human body, the vagus nerve connects the brain stem to the body, transmitting information from the brain to the major organs and other tissues.

allele

One of two or more varying forms of a gene due to genetic mutation. Differing alleles, which can be found at the same spot on a chromosome, produce variation in inherited characteristics such as hair color or blood type. A dominant allele is one whose physiological function—such as making hair blonde—occurs even when only a single copy is present (among the two copies of each gene that everyone inherits from their parents). A recessive allele's traits only appear when two copies are present.

6 points

Optic discOptic nerve: fibres in one eyeOptic chiasm: decussation 60% cross to chiasm and 40% stay to midbrainOptic tract: fibres in both eyeLGNVisual cortex

amygdala

Part of the brain's limbic system, this primitive brain structure lies deep in the center of the brain and is involved in emotional reactions, such as anger or fear, as well as emotionally charged memories. It also influences behavior such as feeding, sexual interest, and the immediate "fight or flight" stress reaction that helps ensure the person's needs are met.

nucleus accumbens

Part of the brain's reward circuitry, or mesolimbic pathway, this small region in the midbrain releases dopamine in response to rewarding experiences.

auditory cortex

Part of the brain's temporal lobe, this region is responsible for hearing. Nerve fibers extending from the inner ear carry nerve impulses generated by sounds into the auditory cortex for interpretation.

autonomic nervous system

Part of the central nervous system that controls internal organ functions (e.g., blood pressure, respiration, intestinal function, urinary bladder control, perspiration, body temperature). Its actions are mainly involuntary.

ion movement between plasma membrane

Passing through ion channels 3 Na+ = 2 K+

Nodes of Ranvier

Periodic gaps in the myelination of axons to which voltage-gated sodium channels are confined and action potentials are generated

olfactory

Pertaining to the sense of smell. When stimulated by an odor, olfactory receptor cells in the nose send nerve impulses to the brain's olfactory bulbs, which then transmit the impulses to olfactory centers in the brain for interpretation.

stress

Physical, emotional, and mental factors that result in bodily or psychological tension. Chronic stress is linked to issues with mental and physical health.

The Emotiv

Portable, easier to use than EEG - Located over the lobes of the cerebral cortex - Standard electrode placement based on anatomical landmarks - Electrode names consist of a letter and a number - EEG measures voltage (electrical potential difference)

Retina has what nerve

Preganglionic parasympathetic fibreCranial nerve 3

Electrogenic (pumps)

Primary active transporters that hydrolyse ATP and use the ready released from ATP hydrolysis to transport ions across cell membranes, leading to the translocation of net charge and maintain an effort of electrical gradient across the membrane.

pupillary light reflex circuit

R eyeRNR LTRLEFT thalamus Dorsal LGNLEFT prepectumLEFT RIGHT edingerwestphal nulceusLEFT RIGHT ciliary ganglion (occulomotor n3)Melanopsin

What does the pigment epithelium do?

Recycle/ regenerate- 12 days Blood flow to photoreceptors Phagocytosis

Koniocellular

Referring to cells in the koniocellular layer of the lateral geniculate nucleus of the thalamus. Konio from the Greek for "dust" referring to the appearance of the cells.Short wave lengths, sensitive cones, colour vision

mental health

Referring to one's psychological, emotional, and social well-being.

brain imaging

Refers to various techniques, such as magnetic resonance imaging (MRI), diffusion tensor imaging (DTI), and positron emission tomography (PET), that enable scientists to capture images of brain tissue and structure and to reveal what parts of the brain are associated with behaviors or activities. Structural brain imaging is concerned with identifying the anatomy of the brain and its changes with disease. Functional brain imaging is concerned with identifying the pattern of activity in the brain when people are at rest or when they are performing a task.

vestibular system

Regions in the body and brain that help support balance in movement. Many people with hearing loss experience some degree of balance difficulties, since the vestibular (or balance) system and the auditory (or hearing) systems are so closely related.

brain waves

Rhythmic patterns of neural activity in the central nervous system, brain waves can also be called neural oscillations.

Ridges and valleys in the brain are called

Ridges - gyri Valleys - sulcus, dividing the front/back half of the brain

Rods

Scotopic Low spatial resolution Light sensitive No detail Many cells 1 photo pigment: rhodopsins

Horizontal cells

Secrete gaba Luminance Depolarise by glutamate

manic-depressive disorder

See bipolar disorder.

deep learning

See machine learning.

mesolimbic circuit

See reward/reinforcement brain network.

What kind of thing is the brain?

Seemingly silly question today. We now known the human brain is a complex system made up of ~86 billion individual neurons (roughly the same number of neurons as there are stars in the Milky Way) linked by ~100 trillion connections. • But a little over than a century ago, there was a vigorous debate about this question. • Many early theories of brain organization posited a system of neighbouring elements fused in a giant, continuous, net -like arrangement or reticulum. This is known as the reticular theory . • One of most famous proponents was Italian neuroanatomist Camillo Golgi (1843 -1926), who developed a ground -breaking staining method that selectively stains neurons and their dendritic trees and axons so they can be observed under a microscope. • Using Golgi's staining method, the Spanish neuroanatomist Santiago Ramon y Cajal (1852 -1934), produced detailed images of neurons and their processes. He arrived at a very different conclusion from that of Golgi. According to Ramon y Cajal, neurons were individual, discrete elements that could make contact with one another, but are not continuously fused. This is known as the neuron theory At the time of Golgi and Ramon y Cajal, synapses couldn't be observed directly, so decisive evidence in favour of the reticular or neuron theory was unavailable. • It was only with the invention of the electron microscope (1930s) that neuroscientists discovered tiny gaps in the synapses - now known as the synaptic cleft -- that connect neurons. • Figure: Electron microscope image of an excitatory synapse. The white arrows indicate the synaptic cleft - the gap between the pre- and post-synaptic neurons. The scale bar represents 400 nm

Which of the following is not necessary for neurons to communicate electrically?

Separation of large amounts of electrical charge, with excess positive charges stored inside the cell

dendrites

Short nerve fibers that project from a neuron, generally receiving messages from the axons of other neurons and relaying them to the cell's nucleus.

3 photo pigments of cones?

Short: blue, tritanopia Medium: green, deuteranopia Long: red, protanopis

Which statement about ionic distributions in nerve cells is true?

Sodium is higher outside cells than inside cells.

action potential

Sometimes called a "spike" or described as a neuron "firing," an action potential occurs when there is a significant increase in the electrical activity along the membrane of a nerve cell. It is associated with neurons passing electrochemical messages down the axon, releasing neurotransmitters to neighboring cells in the synapse.

brain-derived neurotrophic factor (BDNF)

Sometimes referred to as "brain fertilizer," BDNF is a protein that helps promote the growth, maintenance, and survival of neurons.

nucleotide

Sometimes referred to as a nucleic acid, these are the biological building blocks of DNA.

neuroeducation

Sometimes referred to as educational neuroscience, this collaborative, interdisciplinary field of study uses findings in cognitive neuroscience to inform teaching and other educational practices.

oxytocin

Sometimes referred to as the "cuddle chemical," this hormone can work as a neurotransmitter in the brain and has been linked to social attachment and parental care. While there are "love" sprays on the market that are said to contain oxytocin, there is no evidence that these concoctions have any effect on social relationships.

insula

Sometimes referred to as the insular cortex, this small region of the cerebrum is found deep within the lateral sulcus, and is believed to be involved in consciousness, emotion, and keeping the body in balance.

pain receptors

Specialized nerve fibers in the skin and on the surfaces of internal organs, which detect painful stimuli and send signals to the brain.

Visual Cortex also called

Striated cortex, brodmann's area 17

Pore

Structural feature of an ion channel that allows ions to diffuse through the channel.

Selectivity filter

Structure within an ion channel that allows selected ions to permeate, while rejecting other types of ions

parietal lobe

The area of the brain's cerebrum located just behind the central sulcus. It is concerned primarily with the reception and processing of sensory information from the body and is also involved in map interpretation and spatial orientation (recognizing one's position in space in relation to other objects or places).

premotor cortex

The area of the cerebrum located between the prefrontal cortex and the motor cortex, in the frontal lobe. It is involved in the planning and execution of movements.

prefrontal cortex

The area of the cerebrum located in the forward part of the frontal lobe, which mediates many of the higher cognitive processes such as planning, reasoning, and "social cognition"—a complex skill involving the ability to assess social situations in light of previous experience and personal knowledge, and interact appropriately with others. The prefrontal cortex is thought to be the most recently evolved area of the brain.

visual cortex

The area of the cerebrum that is specialized for vision. It lies primarily in the occipital lobe at the rear of the brain and is connected to the eyes by the optic nerves.

gene

The basic unit of inheritance. A gene is a distinct section of DNA code in a cell's chromosome that instructs the cell to make a particular molecule, usually a protein or RNA. Gene defects (genetic mutations) are thought to cause many disorders including brain disorders.

senses

The bodily organs that provide critical information for perception and behavior from the outside world. The five classic senses are: sight, hearing, taste, touch, and smell

central nervous system

The brain and spinal cord constitute the central nervous system and are part of the broader nervous system, which also includes the peripheral nervous system.

cerebrum

The cerebrum is the largest brain structure in humans, accounting for about two-thirds of the brain's mass and positioned over and around most other brain structures. The cerebrum is divided into left and right hemispheres, as well as specific areas called lobes that are associated with specialized functions.

cerebrospinal fluid (CSF)

The clear, colorless liquid found surrounding the brain and spinal cord. This fluid can be analyzed to detect diseases.

What is a synaptic cleft and what is its function?

The cleft is less than 40 nm wide, by comparison a human hair is about 75,000 nanometers The neuron where the signal is initiated is called the presynaptic neuron, while the neuron that receives the signal is called the postsynaptic neuron.

corpus callosum

The collection of nerve fibers connecting the two cerebral hemispheres.

What is the basis of the colour difference between white and grey matter?

The colour difference arises mainly from the whiteness of myelin. In living tissue, grey matter actually has a very light grey colour with yellowish or pinkish hues, which come from capillary blood vessels and neuronal cell bodies. White matter has white fatty insulating protein called myelin Grey matter is made up of grey nuclei

microbiota

The community of various microorganisms found in the digestive tract. Scientists are now learning that microbes found in the microbiota can influence brain development, mood, and behavior.

genome

The complete genetic map for an organism. In humans, this includes about 30,000 genes, more than 15,000 of which relate to functions of the brain.

Which factor is important in determining the membrane potential when there are multiple permeant ions?

The concentration gradient of the individual ionic species The permeability of the membrane to the individual ionic species

Electrochemical equilibrium

The condition in which no net ionic flux occurs across a membrane because ion concentration gradients and opposing transmembrane potentials are in exact balance.

The squid giant axon is useful in neuronal studies because

The cytoplasm in the axon can be extruded, allowing studies of its composition

What is grey matter?

The darker tissue of the brain and spinal cord, consisting mainly of nerve cell bodies and branching dendrites Used for processing

memory

The encoding and storage of information, in a way that allows it to be retrieved later. In the brain, memory involves integrated systems of neurons in diverse brain areas, each of which handles individual memory-related tasks. Memory can be categorized into two distinct types, each with its own corresponding brain areas. Memory about people, places, and things that one has experienced directly or otherwise learned about is referred to as explicit or declarative memory and is highly dependent upon the hippocampus and temporal lobe. Memory about motor skills and perceptual strategies is known as implicit or procedural memory and involves the cerebellum, the amygdala, and specific pathways related to the particular skill (e.g., riding a bicycle would involve the motor cortex).

myelin

The fatty substance that encases most nerve cell axons, helping to insulate and protect the nerve fiber and effectively speeding up the transmission of nerve impulses.

social neuroscience

The field of study investigating the biological systems underlying social processes and behavior.

cognitive neuroscience

The field of study that investigates the biological processes in the brain that underlie attention, memory, and other facets of cognition.

Undershoot Phase

The final, hyperpolarizing phase of an action potential, typically caused by the voltage-dependent efflux of a cation such as K+.

Undershoot phase

The final, hyperpolarizing phase of an action potential, typically caused by the voltage-dependent efflux of a cation such as K+.

frontal lobe

The front of the brain's cerebrum, beneath the forehead. This area of the brain is associated with higher cognitive processes such as decision-making, reasoning, social cognition, and planning, as well as motor control.

Rising phase

The initial, depolarizing, phase of an action potential, caused by the regenerative, voltage-dependent influx of a cation such as Na+ or Ca2+.

Resistance

The input resistance of a neuron reflects the extent to which membrane channels are open. A low resistance (high conductance) implies open channels, while high resistance implies closed channels.

Resting membrane potential

The inside-negative electrical potential that is normally recorded across all cell membranes by the Na+/K+ ATPase and the K+ leak channels. In most cells, the resting membrane potential is approximately -70 mV with respect to the outside of the cell.

synapse

The junction where an axon approaches another neuron or its extension (a dendrite); the point at which nerve-to-nerve communication occurs. Nerve impulses traveling down the axon reach the synapse and release neurotransmitters into the synaptic cleft, the tiny gap between neurons.

medulla oblongata

The lower part of the brain stem, responsible for life-regulating functions like breathing and heart rate.

vertebral arteries

The major arteries of the neck, which merge to form the basilar artery.

cerebellar artery

The major blood vessel providing oxygenated blood to the cerebellum.

DNA (deoxyribonucleic acid)

The material from which the 46 chromosomes in each cell's nucleus is formed. DNA contains the codes for the body's approximately 30,000 genes, governing all aspects of cell growth and inheritance. DNA has a double-helix structure—two intertwined strands resembling a spiraling ladder.

Equilibrium potential

The membrane potential at which chemical and electrical forces are balanced (at electrochemical equilibrium) for a single ion.

Threshold potential

The minimum critical level of membrane potential to which a membrane potential must be depolarized to initiate an action potential

amino acid neurotransmitters

The most prevalent neurotransmitters in the brain, these include glutamate and aspartate, which can increase the electrochemical activity of neurons, as well as glycine and gamma-amino butyric acid (GABA), which inhibit that electrochemical activity.

What is diffusion in the context of synaptic transmission?

The movement of particles from an area of high concentration to an area of low concentration. Eventually, the neurotransmitter molecules must be cleared from the synaptic cleft Some of them will simply drift away in a process called diffusion

Myelin

The multi laminated wrapping around many axons formed by oligodendrocytes or Schwann cells.

Cellular diversity in the nervous system

The nervous system is composed of diverse neuronal and nonneuronal cell types with different molecular, anatomical, and functional features. All neurons have some basic component parts in common: cell body (soma), axon, dendrites.

peripheral nervous system

The nervous system outside the brain and spinal cord.

default-mode network

The network indicates that the brain remains active even if not involved in a specific task. Even when you are daydreaming, the brain is in an active state.

postsynaptic cell

The neuron on the receiving end of a nerve impulse transmitted from another neuron.

cortex

The outer layer of the cerebrum. Sometimes referred to as the cerebral cortex.

Falling Phase

The part of an action potential characterized by a rapid fall of membrane potential from positive to negative.

motor cortex

The part of the brain's cerebrum, just to the front of the central sulcus in the frontal lobe, that is involved in movement and muscle coordination. Scientists have identified specific spots in the motor cortex that control movement in specific parts of the body, the so-called "motor map."

frontal operculum

The part of the frontal lobe that sits over the insula.

cochlea

The part of the inner ear that transforms sound vibrations into neural impulses.

gray matter

The parts of the brain and spinal cord made up primarily of groups of neuron cell bodies (as opposed to white matter, which is composed mainly of myelinated nerve fibers).

What does the word medial refer to in the brain?

The parts of the brain in the cross-sectional image that are close to the centre of the brain

retina

The sensory membrane at the back of the eye that processes light information to facilitate sight.

synaptic cleft

The small space between neurons where neurotransmitters are released.

Conduction velocity

The speed at which an action potential is propagated along the length of an axon

Diagnostic and Statistical Manual of Mental Disorders (DSM)

The standard classification manual published by the American Psychiatric Association for mental health professionals to diagnose and treat mental disorders.

consciousness

The state of being aware of one's feelings and surroundings; the totality of one's thoughts, feelings, and impressions.

resting state

The state of the brain when it is not consciously engaged in an explicit task. Brain imaging techniques such as fMRI can be used to measure the residual activity that occurs in this state.

amyloid plaque

The sticky, abnormal accumulations of amyloid-beta protein aggregate around neurons and synapses in the memory and intellectual centers of the brain, in people with Alzheimer's. These are sometimes referred to as neuritic plaques or senile plaques. While amyloid plaques have long been considered markers of Alzheimer's, they are also found to some extent in many cognitively normal elderly people. The plaques' role in Alzheimer's neurodegeneration remains unclear.

double helix

The structural arrangement of DNA, which looks something like an immensely long ladder twisted into a helix, or coil. The sides of the "ladder" are formed by a backbone of sugar and phosphate molecules, and the "rungs" consist of nucleotide bases joined weakly in the middle by hydrogen bonds.

Cellular components of the nervous system PRINCIPLES OF BRAIN ORGANISATION

The structure and function of mechanisms are intimately related.

Cellular components of the nervous system PRINCIPLES OF BRAIN ORGANISATION

The structure and function of mechanisms are intimately related.

A student new to neuroscience research is practicing recording resting membrane potentials from giant squid axons. During one of the trials, the resting membrane potential, which is normally around -60 mV, measured -15 mV. Which statement best describes what might have occurred during the experiment?

The student added too much potassium to the extracellular solution

neuroscience

The study of the brain and nervous system, including their structure, function, and disorders. Neuroscience as an organized discipline gained great prominence in the latter part of the 20th century.

molecular biology

The study of the structure and function of cells at the molecular level and how these molecules influence behavior and disease processes. Molecular biology emerged as a scientific discipline only in the 1970s, with advances in laboratory technologies for isolating and characterizing DNA, RNA, proteins, and other small biological entities.

To view near

Thick lensRelax ciliary mIncrease elasticity

To view distant objects, what happens to the lens?

Thin lensContract ciliary mZonule fibres reduce

frontotemporal degeneration (FTD)

This is a common type of dementia caused by the loss of neurons in the frontal lobes. This disorder often strikes earlier than Alzheimer's disease or other forms of dementia, with most patients diagnosed between their late 40's and early 60's. It also tends to present with more prominent behavior and social impairments as opposed to memory loss, though memory loss is common in later stages of disease.

substantia nigra

This small region in the midbrain is part of the brain's reward system. In Parkinson's disease, the dopamine neurons in this region die off, leading to the disorder's movement-related and cognitive symptoms.

metabolize

To break down or build up biochemical elements in the body, effecting a change in body tissue. For example, neurons and other brain cells metabolize glucose, a blood sugar, to derive energy for transmitting nerve impulses.

Sodium and the action potential

When a neuron reaches threshold, this increases the probability that voltage-gated Na+ channels will open. This causes Na+ ions to rush into the cell (due to the concentration gradient)

What is a coronal/frontal plane of the brain?

When a slice is made perpendicular to the long axis of the brain

Define electrochemical equilibrium & equitation name

When chemical and electrical gradients are exactly balancedThe Nernst Equation

Refractory period

a brief period of time after a neuron has fired an action potential during which the neuron is difficult or impossible to elicit

Goldman equation

a mathematical formula that takes into consideration the relative permeability of the membrane to different ions.Vm = 58 log

Neurons

a nerve cell; the basic building block of the nervous system

What is a neuron?

a nerve cell; the basic building block of the nervous system

Central Nervous System (CNS)

brain and spinal cord

macular degeneration

breakdown or thinning of the tissues in the macula, resulting in partial or complete loss of central vision

grey matter in brain

cell bodies

soma

cell body

Glial cells

cells in the nervous system that support, nourish, and protect neurons

Function of Glial cells - 3 types

cells in the nervous system that support, nourish, and protect neurons. Promote regrowth of damaged neuronsAstrocytes - CNS, maintain chemical environment for neuronal signallingOligodendrocytes - CNS, myelin on axonsMicroglial cells - scavenger cells removing debris

Organization of the human nervous system

central nervous system (brain and spinal cord) and peripheral nervous system (cranial and spinal nerves)

achromatopsia

complete color blindness, cones fine

artificial intelligence (AI)

computer programs or systems designed to perform tasks that normally require human intelligence, including problem-solving, learning, and decision-making behaviors.

strabismus

crossed eyes infancy

scotoma

dark spot in the visual field

Studies of the ionic basis of the action potential in squid giant axon found that

decreasing sodium outside the cell decreases the size of the action potential.

Opening of Na+ channels causes

depolarization - Inward rush of Na+ generating AP

presbyopia

impaired vision as a result of aging Worst myopia

cerebral akinetopsia

inability to perceive moving objects dorsolateral parieto-occipital cortex bilat lesion

Glaucoma

increased intraocular pressure Fail to drain Damaged retinal neurons

axonal membranes are

leaky! Loose electrical current therefore require action potentials to maintain the current.

EEG is not useful for...

localisation of neural processes

The synaptic potential

makes communication between nerve cells possible.

microglial cell

phagocytic glial cell that removes waste products from the central nervous system

superior colliculus

receives visual sensory input (superman has superior vision)

What are vesicles?

round sacs containing neurotransmitters at the axon terminal

Lou Gehrig's disease

see amyotrophic lateral sclerosis (ALS)

Neural circuits

signal-relaying network of interconnected neurons

Ribosomes

site of protein synthesis. Decodes messages and forming peptide bonds

In the phase labeled B, _______ ions are moving _______ the cell.

sodium; into

The squid giant axon is useful in neuronal studies because

the cytoplasm in the axon can be extruded, thus allowing studies of its composition.

Hodgkin and Katz proposed that sodium was the predominant ion associated with the firing of an action potential because

the membrane potential approaches Na+ Nernst potential during the rising phase

Hodgkin and Katz proposed that sodium was the predominant ion associated with the firing of an action potential because

the membrane potential approaches the Na+ Nernst potential during the rising phase.

emmetropia

the normal relationship between the refractive power of the eye and the shape of the eye that enables light rays to focus correctly on the retina

Pyramidal neurons

the primary neurons found in the pyramidal tract, which are pyramid shaped

Myelination

the process by which glial cells (oligodendritez or Schwann cells) wrap around axons to form multiple layers of glial cell membrane, thus insulating the axon with myelin, a fatty substance that increases conduction velocity of nerve impulses from neuron to neuron

Peripheral Nervous System (PNS)

the sensory and motor neurons that connect the CNS to the rest of the body

Refractory period ends when

the sodium channels are no longer inactivated

conduction velocity

the speed at which an action potential is propagated along the length of an axon

Electrophysiology

the study of the electrical activity of cells Extracellular recording (placed near cell)Intracellular recording (recorded inside of the cell)

What is a postsynaptic neuron?

transmits impulses away from the synapse

What are pyramidal neurons?

upper motor neurons that are involved with initiation of skilled voluntary movements

binocular field of vision

where left and right fields of vision overlapAB FP CD

Injected current into axon

will decay with increasing distance from the injection site (if no AP is present)

What is the Nernst equation?

ΔG = -nFΔE° Explanation: The relationship between free energy change and emf of a cell is ΔG = -nFE, where n is the number of moles of electrons transferred, F stands for Faraday and is equal to 96495 coulombs and E is the emf of the cell.

What is a neuron?

• Neurons or cells that are specialised for long-distance electrical signalling and intercellular communication. • Composed of a cell body or soma, dendrites, and axon. • Dendrites are branched projections of neurons that receive signals or electrical impulses (known as action potentials or spikes) from other neurons and propagate these signals to the cell body, or soma, of the neuron. • Axons are long, slender projections of neurons that conducts electrical impulses away from the cell body or soma.