psych exam 1: lecture 5

anatomy of neuron: what is a neuron

nerve cell

what is an axon

sending end of the neuron

what is a dendrite

the recieving end of the neuron

what is myelin sheath

cover some neurons to make transmission faster

what is synapse

where the axon of neuron1 meets the dendrite of neuron 2

what is the difference between sensory, motor, and interneurons

sensory: bring things from body to nervous system (like heat)

motor:nervous system to body (telling your body to move away from heat)

interneuron: local connector between spine and brain (processes info to tell u to move away from heat)

what are mirror neurons

activate when we perform an action or watch someone else perform that action

what is resting potential and what roles do sodium and potassium have in it

difference in electrical charge between the inside and the outside of a neuron when its at rest

sodium: high level outside of neuron

potassium: high level inside of neuron

what is an action potential and what happens to sodium and potassium during it

brief reversal of the neurons electrical charge that travels down the axon

sodium channels open and sodium comes in and makes charge more positve, then potassium channels open and potassium moves out and neurons return to resting state (reestablishes resting potential)

what is depolarization, repolarization, and hyperpolarization?

depolarization: sodium enters neurons and inside becomes less negative (more positive)

repolarization: potassium leaves neurons and neurons returns toward resting potential

hyperpolization: neuron becomes temporarily more negative then resting potential before returning to normal (bc when k channels stay open for too long)

what is the sodium potassium pump

restores sodium and potassium balance after action potential and reestablishes the resting potential

What is the process of propagation of the action potential travel down the axon and how does myelin affect it

waves of sodium entering and potassium exiting neuron propogates the action potential

with myelin: it makes the process FASTERR bc of saltatory conduction

without myelin: continuous conduction which is slower

what is myelin

fattying covering that is insulation around the axon of the neuron for faster transmission

what is the difference between gray matter and white matter?

gray matter: cell body (somas) and dendrites

white matter: myelinated axons and glial cells (communcation pathway between areas of the brain)

what is a synapse

small gap between neurons where communcation occurs

How does a presynaptic neuron communicate with a postsynaptic neuron?

action potential propagets along the axon of the presynaptic neuron —> this releases exictatory and inhibitory neurotransmitters into the synapse —> these attach to receptor proteins on the postsynaptic neurons dendrites

difference between excitatory and inhibitory neurotransmission

excitatory: depolarizes the postsynatic neuron (makes more positive)

• increases likelihood of action potential

inhibitory: makes action potential less likely (makes more negative)

what is a neurotransmitter

chemical messenger that allows neurons to communicate

Acetylcholine (ACh)

released by motor neurons —> controk skeletal muscles (attention, arousal, memory)

• can be stimulated by nicotine

Dopamine

controls voluntary movement

“reward pathway”

cocaine and amphetamines elevate activity at DA synapses

Norepinephrine

mood and arousal

Cocaine and amphetamines elevate activity at NE synapses

Serotonin

Sleep/wakefulness, eating, aggression

Prozac and SSRIs (antidepressants) affect serotonin circuits

GABA

anxiety and sleep/arousal regulation

inhibitory transmitter

glutamate

learning and memory

exitatory transmitter

endorphins

pain relief, stress response, and eating behavior

what is reputake

neuron takes neurotransmitters back up after they are done binding

what is enzyme deactivation

when synaptic enzymes degrade neurotransmitters

neurotransmitters are tranpsorted back to axon terminal to recycle

How do SSRI antidepressants work?

SSRIs block the reuptake of serotonin, leaving more serotonin available in the synapse.