PSY 210 Final Exam - Review (Matthew)

Neurons (purpose)

signaling

Astrocytes

support BBB

Oligodendrocytes

create myelin sheaths in CNS

Microglia

immune cells of CNS

Schwann cells

myelinate cells in the PNS

Action potential steps

depolarization (Na⁺ in), repolarization (K⁺ out), hyperpolarization, rest

Ion Gradients in an AP

Na⁺ pushed in, K⁺ pushed out, Cl⁻ balances charge

Refractory periods

span of time after an AP in which a neuron cannot fire another AP

Absolute refractory period

no AP possible

Relative refractory period

AP just requires stronger stimulus

Chapter 2

Order of events at synapse

action potential, Ca²⁺ influx, vesicle release, receptor binding

EPSPs

excitatory, small depolarizations, make neuron MORE likely to fire

IPSPs

inhibitory, small polarizations, make neuron LESS likely to fire

Temporal summation

synapse fires repeatedly in quick succession, EPSPs add together over time to reach threshold.

Spatial summation

Multiple synapses fire at the same time, EPSPs add together across space to reach threshold.

Agonist

activates receptor

Antagonist

blocks receptor

Ionotropic receptors

fast acting receptors that open an ion channel directly

Metabotropic

slow response receptors that use GPCR pathways to change cell behavior

Chapter 3

Research methods

know what it measures/manipulates, structure vs function, human/animal.

TMS

manipulates brain; humans; affects function.

Gene knockout

manipulates genes; animals.

Optogenetics

manipulate activity with light; animals.

DREADDs

chemogenetic manipulation; animals.

EEG

measures electrical activity; function; humans/animals.

MEG

magnetic fields; function; humans.

PET

radioactive tracers; function; humans/animals.

fMRI

blood flow; function; humans.

CT/CAT

structure; humans.

MRI

structure; humans/animals.

Chapter 4

Methods to study a gene's contribution to a trait or disorder

GWAS

compares many genomes to find variants linked to a trait.

Candidate gene

tests specific genes.

Twin studies

compare MZ vs DZ twins.

Adoption studies

biological vs adoptive environment.

Major developmental processes (in order)

Neurogenesis

new neurons created

Migration

neurons move to proper location.

Differentiation

neurons specialize.

Synaptogenesis

synapse formation.

Apoptosis

programmed cell death of excess neurons

Pruning

removal of unused synapses.

Myelination

glial wrapping of axons.

Structural plasticity

Physical changes in the brain, forming new synapses, dendritic branching, or growing new neurons.

Functional plasticity

Changes in how existing neurons and synapses function

Chapter 5

Retina cell pathway

photoreceptors, bipolar, ganglion cells, brain

Photoreceptors

detect light and convert to electrical signal

Bipolar cells

receive signal from photoreceptors, transfer to ganglion cells

Ganglion cells

integrate signals from bipolar cells, axons form optic nerve

Horizontal cells

Connect photoreceptors and bipolar cells laterally, help with contrast

Amacrine cells

Connect bipolar and ganglion cells laterally, modulate motion detection and temporal vision.

Retinal cells that use graded potentials

photoreceptors & bipolar cells

Retinal cells that use action potentials

ganglion cells

Concentric receptive fields (bipolar cells)

Bipolar cells respond to light in a center-surround pattern:

On-center (bipolar cells)

Excited when light hits the center of their receptive field, inhibited by light in the surround.

Off-center (bipolar cells)

Inhibited by light in the center, excited by light in the surround.

Dorsal pathway

where/how, runs from occipital to parietal lobe; processes motion, spatial location, and visually guided actions

Ventral pathway

what, runs from occipital to temporal lobe, processes object recognition, color, and form

Sound transduction pathway

vibration, basilar membrane, hair cell bending, ion channels open, signal

Touch sensation

fast transduction via myelinated axons, crosses at medulla

Pain sensation

slower transduction, crosses at spinal cord

Taste receptors

sweet, salty, sour, bitter, umami, each use different receptors/ion channels

NREM Stage 1

Mostly theta waves, light sleep

NREM Stage 2

Theta waves with sleep spindles and K-complexes, intermediate sleep

NREM Stage 3 (slow-wave sleep)

Delta waves, high amplitude, deep sleep

REM sleep

sawtooth waves, rapid eye movements, muscle atonia

SCN

internal clock regulating circadian rhythms with rhythmic APs

Homeostasis

Maintaining internal stability at a set point

Allostasis

Achieving stability through dynamic adjustments based on anticipated or ongoing stressors (predictive regulation)

Arcuate nucleus (ARC)

Central hub with two main neuron populations:

NPY/AgRP neurons

Stimulate hunger

POMC/CART neurons

Promote satiety

Paraventricular nucleus (PVN)

Integrates signals from the ARC and regulates food intake

Lateral hypothalamus (LH)

promotes eating when activated

Ventromedial hypothalamus (VMH)

inhibits feeding when activated

NPY (Neuropeptide Y), AgRP (Agouti-related peptide)

Increase appetite

GABA (hhs)

released by AgRP neurons to inhibit satiety signals.

Leptin

Hormone from fat cells, inhibits NPY/AgRP and activates POMC/CART neurons, reduces hunger.

Ghrelin

Hormone from the stomach, activates NPY/AgRP neurons, increases hunger

Insulin

Signals energy, suppresses food intake

Organizing effect

Hormonal effects during development that produce long-lasting behaviors or physiology.

Activating effect

Hormonal effects that temporarily influence behavior or physiology

SRY Gene

sex determining gene located on Y chromosome

Females

Lack of SRY gene and androgens cause gonads to become ovaries, Wolffian ducts degenerate, Mullerian ducts develop into fallopian tubes, uterus, upper vagina

Males

Androgens cause Wolffian ducts to develop into seminal vesicles and vas deferens, Testes produce Mullerian inhibiting hormone (MIH) which causes Mullerian ducts to degenerate

MPOA (medial preoptic area)

Hypothalamic center in the brain that drives parenting behaviors in both males and females.

Oxytocin

Hormone that promotes bonding, caregiving, and responsiveness to infant cues.

Prolactin

Supports caregiving behavior, high in mothers and increased in human fathers.

Estrogen/Progesterone (females)

Pregnancy hormones that prime the brain for maternal behavior

Testosterone (males)

Supports paternal care when lowered after fatherhood, modulates motivation

Sex bias

When research includes both sexes but treats one sex differently, interprets results through one sex's lens, or gives unequal weight (usually favoring males).

Sex omission

When research doesn't include one sex at all (historically females)