Behavioral Neuroscience- Final Exam

Nucleus

keeps neuron alive

axon

sends signals

dendritic spines

too many —> autism, sensory issues

too few —> dementia

too many & too few —> schizophrenia

dendrites

collect information

axon hillick

sums/combines info to determine if it should send signal

axon terminals

sends info to the next neuron

Nodes of ranvier & Myelin sheath

speeds up signal

Oligodendroglia

Myelin sheath- central nervous system

Schwann cells

Myelin sheath- peripheral nervous system

Microglia

“janitors”- clean up everything

Astrocytes

Repair neurons and BBB (Blood-Brain Barrier)

Hyperpolarization

Process where inside of the cell becomes more negative (less positive), bringing it further from the threshold for firing an action potential

Depolarization

Process where inside of cell becomes less negative (more positive), bringing it closer to the threshold for firing an action potential

Would a neuron be more or less likely to fire if permeability to calcium was increased?

The neuron would be more likely to fire because calcium is positive and it would move from the outside to the inside, causing it to become more positive/less negative; depolarization; EPSP

Would a neuron be more less likely to fire if permeability to potassium was increased?

The neuron would be less likely to fire because potassium is positive, but it would be moving from the inside to the outside, causing it to become less positive/more negative; hyperpolarization; IPSP

Would a neuron be more or less likely to fire if permeability to sodium was increased?

The neuron would be more likely to fire because sodium is positive and it’s on the ouside, so the neuron would move to the inside causing it to become more positive/less negative; depolarization; EPSP

Would a neuron be more or less likely to fire if permeability to chloride was decreased?

The neuron would be more likely to fire because chloride is negative but it would move less from the outside to the inside, causing the inside to become less negative/more positive that it would’ve been if permeability was increased; depolarization; EPSP

EPSP

change in the neuron’s charge that makes it MORE likely to fire an action potential

IPSP

change in the neuron’s charge that makes it LESS likely to fire an action potential

motor neurons

carry signals from the brain/spinal cord to muscles or glands to tell them to move

sensory neurons

carry information from the body or environment to the brain/spinal cord

interneurons

connect sensory and motor neurons and process information; “in-between”

Process of neurotransmission

1. Neurotransmitters bind to receptors on the postsynaptic neuron (resting membrane potential: -70mv)

2. Ion channels open or close, allowing ions to flow in or out

3. Small changes in membrane potential occur as EPSPs or IPSPs

4. Through summation, multiple EPSPs can add together to reach the threshold

5. If the threshold is reached, an action potential occurs: voltage-gated sodium (Na+) channels open (depolarization)

6. Voltage-gated potassium (K+) channels then open (hyperpolarization) to reset the membrane

7. The action potential travels down the axon to the axon terminals

8. Depolarization of the terminal opens voltage-gated calcium (Ca+) channels

9. Calcium ion flood in, causing vesicles to fuse with the presynaptic membrane

10. Neurotransmitter is released into the synaptic cleft

11. Neurotransmitter binds to receptors on the next neuron, repeating the process

Hindbrain

least complex — survival needs

Midbrain

reward, basic sexual behavior

Forebrain

most complex — decision making, memory

Pons

responsible for sleep; hindbrain

Cerebellum

gross (big) motor movements; hindbrain

Medulla (oblongata)

involuntary functions: heart rate, breathing

Periaqueductal gray

pain, defensiveness, lordosis (animals); midbrain

Basal Ganglia

section of things that work with habits; forebrain

Hippocampus

deals with memory; forebrain

Amygdala

deals with fear and aggression

Thalamus

info gets sent into it —brings information to where it needs to go

Hypothalamus

feeding, fighting, fleeing, sex; forebrain

Parietal lobe

feels sensations

Temporal lobe

language, process of hearing something

Occipital lobe

primary visual cortex (eyes in the back of your head)

Prefrontal cortex

regulates behavior, planning, imagining future; cerebral cortex

Glutamate

excitatory —> learning, memory, neural activation

GABA

inhibitory —> reduces neural activity

Endorphins

pain relief, pleasure, euphoria

Serotonin

mood regulation, sleep, appetite, digestion

Dopamine

reward, motivation, movement, mood

Norepinephrine

arousal, alertness, stress response

Histamine

wakefulness, helps maintain alertness

Adrenaline (Epinephrine)

fight or flight response, increases heart rate, alertness

Acetylcholine

promotes wakefulness and REM sleep; cortical activation and dreaming

EEG

measures electrical activity of the brain; good for sleep, seizures, brain wave patterns

MRI

detailed images of brain structures using magnets; good for soft tissue, brain anatomy

fMRI

measures brain activity via blood flow; good for seeing which areas are active during tasks

PET scan

measures brain metabolism using radioactive tracers; good for detecting brain regions & disease (e.g. Alzheimer’s)

What is the cellular pathway from light hitting the eye to going to the optic nerve?

1. Light hits the photoreceptors (rods and cones), causing them to reduce their neurotransmitter release

2. This signals bipolar cells, with horizontal cells helping adjust and refine the signal

3. Bipolar cells then activate ganglion cells, whose axons form the optic nerve that carries the information to the brain

What happens from the sound wave entering your ear to auditory perception?

1. Sound waves enter your ear canal and hits the ear drum making it vibrate

2. Vibrations move through the hammer, anvil and stirrup, which amplify the sound and pass it into the oval window

3. Oval window then pushes on the fluid inside the cochlea, creating waves that travel along the basilar membrane

4. as the membrane moves, the cilia bend against the tectorial membrane

5. tip links stretch and open ion channels, turning movement into electrical signals that are interpreted as sound

Salty

sodium —> ionotropic

Sweet

sucrose —> metabotropic

Sour

acids linked to hydrogen —> ionotropic

Bitter

guinine —> metabotropic

Umami

glutamate —> metabotropic

Fat

fatty acids —> metabotropic

Taste aversions

one trial, long delay, gustatory stimuli (stimulate taste buds)

Pheromones

vomeronasal organ: responsible for animals sensing/smelling other animals

Merkel disks

very light touch, textures, edges

Ex: holding sandpaper, feeling a coin in your pocket, feeling of a hair on your neck

Meissner’s corpuscles

low frequency vibrations and pressure

Ex: feeling the rumble of construction outside, rubbing sandpaper

Pacinian corpuscles

high-frequency vibration

Ex: cell phone vibrating in your pocket (high freq)

Ruffini endings

stretching of the skin

Ex: your elbow moving while lifting weights

Vestibular sense

balance; knowing which way our body is facing

Osmotic thirst

craving water due to too much salt

Hypovolemic thirst

craving for water and salt due to low blood volume from fluid loss

Ghrelin

makes you hungry

Lepin

satiety; long-term hormone

OEA

delays next meal — time

CCK

portion size — amount

peptide YY

satiety — nutrients

GLP1

makes you feel less hungry

Endocannabinoids

makes you feel more hungry and makes things taste better

Vagus nerve

responsible for recognizing that stomach is stretching

Lateral hypothalamus

facilitates feeding; makes you want to eat

Ventromedial hypothalamus

inhibits/decreases feeding

Sleep - Stage 1

falling asleep; alpha to theta; hypnic jerk

Sleep - Stage 2

most time spent; sleep spindles & k-complexes (keep us asleep)

sleep spindles: period of high frequency; k-complexes: period of high amptitude

Sleep - Stage 3

deep sleep; delta waves; sleep walking/talking/sex

Sleep - REM

rapid eye movement; most dreams/nightmares; highest brain activity; linked to healing & memory consolidation

Suprachiasmatic nucleus

part of hypothalamus

Light → melanopsin receptors → SCN → pineal gland → ↑ melatonin → sleepiness

Zeitgeber

time giver; stimulus that drives circadian rhythm

Adenosine

builds in the brain during wakefulness, makes you feel tired

Orexin

promotes wakefulness; low activity supports sleep

Organizing effects of hormones

early, long-lasting

Activating effects of hormones

later, short

Female sexual differentiation

Chromosomes: XX
Gonads: develop into ovaries (no SRY gene)

Hormones: low testosterone; estrogen produced by ovaries later in development

Mullerian ducts —> develop into uterus, fallopian tubes, and upper vagina

External genetalia: clitoris, labia, lower vagina

Male sexual differentiation

Chromosomes: XY

Gonads: SRY gene triggers testes formation

Hormones:

Testes produce AMH —> prevents female internal structures

Testosterone —> Wolffian ducts (epididymis, vas deferens, seminal vesicles)

Dihydrotestosterone: external genetalia (penis, scrotum, prostate)

What would happen if AMH didn’t work?

XY individual —> external male genetalia —> Mullerian ducts persist —> internal female structures (uterus, fallopian tubes) —> PMDS (Persistent Mullerian Duct Syndrome)

Testosterone

desire to seek out sexual partners

Estrogen

desire to have sex

Dopamine (reproduction)

mate preference; testosterone increases dopamine

Oxytocin

maternal behavior, increases attention to social cues

Adrenaline (reproduction)

misattribution of arousal

Vasopressin

paternal behavior

Nucleus accumbens

reward + desire to have sex

Prefrontal cortex (reproduction)

decrease in sexual behavior