Nervous System - Neurotransmitters and Synapses

3 categories of neurotransmitters

amino acids, biogenic amines, polypeptides

glutamate, glycine, and GABA are examples of what category of neurotransmitter

amino acids

acetylcholine, dopamine, norepinephrine, and serotonin are examples of what category of neurotransmitter

biogenic amines

acetylcholine

stimulates muscle contraction

dopamine

mood, happiness

serotonin

sleepiness and mood

endorphins

pain reduction, mood

neurons communicate with other cells at ____

synapses

neurons communicate with each other at synapses:

in the brain, a _____ neuron may have chemical ___ with hundreds or thousands of ____ neurons, which may use different ____

postsynaptic, synapses, presynaptic, neurotransmitters

neurons communicate with each other at synapses:

____ for a given neurotransmitter on the _____ cell may be of different types with different actions

receptors, postsynaptic

neurons communicate with each other at synapses:

this complexity in ___ function helps explain the complexity of ___ function

synapse, brain

2 types of neurotransmitter receptors

ionotropic and metabotropic

ionotropic receptors

ligand gated ion channels that cause changes in ion movement

ionotropic receptors response

fast and short-lived

metabotropic receptors

G protein linked receptors that produce second messengers that induce signaling cascades

metabotropic receptors response

slow and long-lived

2 types of synapses

excitatory and inhibitory

____ synapses shift membrane potential towards threshold

excitatory

excitatory (EPSPs) synapses produce

graded membrane depolarization

____ synapses shift membrane potential away from threshold

inhibitory

____ produce graded membrane hyperpolarizations

inhibitory synapses (IPSPs)

1-4 are

excitatory synapses

two types of neurotransmitters

excitatory and inhibitory

excitatory neurotransmitters increase ____ and chance for ____ to be achieved

membrane permeability, threshold

____ decrease membrane permeability and chance for threshold to be achieved

inhibitory neurotransmitters

excitatory synapse

inhibitory synapse

gamma-aminobutyric acid known as

GABA

GABA ____ the activity of the neurons to which it binds

reduces (inhibitor)

most common type of receptor

GABA

what percentage of all synapses work with GABA

40

GABA has a _____ effect

tranquilising

tranquilising effect

reduces anxiety and calms body by slowing down cns

low levels of GABA associated with (2)

anxiety and phobia

sedatives bind to ____ receptors

GABA

agonist

molecule that has same effect on postsynaptic neuron as the neurotransmitter itself does

antagonist

molecule that blocks the effect that the neurotransmitter normally has on the postsynaptic neuron

____ are drugs that occupy receptors and activate them

agonist

____ are drugs that occupy receptors but do not activate them

antagonist

agonist

agonist and antagonist together leads to ___ activation

less

antagonist alone

nerve impulse:

speed is proportional to the

size of the axon

nerve impulse:

greater diameter =

faster impulse

nerve impulse:

(myelinated/unmyelinated) axons conduct impulses faster

myelinated

synapse

junction between two communicating neurons

nerve pathway: nerve impulse travels from neuron to

neuron

nerve pathway specifically

dendrite, cell body, along axon, synapse (gap), dendrite

A

neuron (axon)

B

neuron (dendrite)

1

mitochondria

2

vesicle

3

receptor

4

synapse

5

receptor

6

calcium channel

7

releases neurotransmitter

8

re-uptake

____ poisoning can be fatal to humans and animals and can occur by ____ and ____

strychnine, inhalation, swallowing

strychnine prevents the proper operation of the

chemical that controls nerve signals to the muscles

strychnine poisoning:

the chemical controlling nerve signals works like the body’s ______ for muscles. when this ____ does not work correctly, muscles throughout the body have ______

off switch, off switch, painful spasms

cocaine:

____ binds to receptors and is eventually recycled back into the ____

dopamine, neuron

if cocaine is present, it attaches to the _____ and ____ the normal recycling process, resulting in a ____ of dopamine in the ____, which contributes to the ____ effects of cocaine

dopamine transporter, blocks, buildup, synapse, pleasurable

ecstasy (mdma):

____ is the feel good neurotransmitter and helps regulate ____

serotonin, body temperature

____ (mdma):

our brain cells recycle serotonin ____ the cells and ____ of the synapse using ____

ecstasy, back into, out, serotonin reuptake transporters

ecstasy takes these upkeep transporters and ___ their roles. this causes a massive flood of ____ from the ___ into the ___

reverses, serotonin, brain cells, synapse

the most common cause of ecstasy-related death is

overheating/hyperthermia

antidepressants:

zoloft is a part of a class of drugs called

selective serotonin reuptake inhibitors

SSRIs ____ the uptake of serotonin ___, keeping mood elevated for a ____ time

inhibit, back into the cell, longer

heroine/opiates activates ____, blocks ____, releases more ____

opiate receptors, release of GABA, dopamine

____ mimic dopmnine by ____ to receptors

amphetamines, binding

amphetamines:

dopamine (does/does not) re-enter the cell, ___ the cell’s supply

does not, depleting

PRIALT

a calcium channel blocker that is used to inhibit pain transmission from the spinal cord

PRIALT does not bind to ____ receptors

opioid

impulse processing

do not need to think about (stop sign)

____ groups of neurons that make hundreds of synaptic connections and work together to perform a common function

neuronal pool

neuronal pools help us remember ____ tasks, like (2)

sequential, tying a shoe or riding a bike

spinal reflex/reflex arc:

afferent information converts to

efferent activity without going through the brain

nerve pathway that is involuntary and instant

spinal reflex/reflex arc

____ maintains uprightness

knee-jerk reflex

knee-jerk reflex:

____ receptors in the patellar tendon send _____ to the ____

stretch, action potentials, spinal cord

knee-jerk reflex:

the ____ neuron synapses with a ___ neuron, sending a(n) ____ to the leg muscle

sensory, motor, action potential

withdrawal reflex

avoidance of painful stimuli (touch and pull back)