Synapses & Neural Integration pt 2

Question 1

what is neural integration

Answer 1

nervous system communication involving more than one presynaptic and postsynaptic cell at any one time

Question 2

what are the types of neural integration

Answer 2

• divergence/convergence
• axon hillock and threshold
• summation
• frequency coding

Question 3

describe axon divergence

Answer 3

axon has many collaterals that communicate with many other neurons

Question 4

describe axon convergence

Answer 4

any given neuron receiving communication from tons of neurons

Question 5

describe axon hillock in relevance to threshold

Answer 5

AH of postsynaptic neuron acts as an integrator which sums signals of all active synapses

Question 6

why is summation needed for neural integration

Answer 6

single EPSP is generally not enough to depolarize post synaptic neuron to threshold

Question 7

what are the types of neural summation

Answer 7

temporal (one at a time) and spatial (several at the same time)

Question 8

describe frequency coding

Answer 8

considers number of action potentials (affected by summation) to find the degree of depolarization at the axon hillock

Question 9

what is presynaptic modulation

Answer 9

regulation of communication across another synapse

Question 10

what are the two possible effects of presynaptic modulation

Answer 10

release of NT can be enhanced or suppressed

Question 11

what is presynaptic facilitation

Answer 11

release of neurotransmitter can be enhanced

Question 12

what is presynaptic inhibition

Answer 12

release of neurotransmitter can suppressed

Question 13

what are the classes of the neurotransmitters

Answer 13

choline derivative, biogenic amines, amino acids, purines, neuropeptides, unique molecules

Question 14

what are examples of purines

Answer 14

ATP, ADP, adenosine

Question 15

what are examples of unique molecules

Answer 15

nitric oxide, endocannabinoids

Question 16

what are examples of choline derivatives

Answer 16

acetylcholine

Question 17

what are examples of amino acids

Answer 17

glutamate, aspartate, glycine, GABA

Question 18

what are examples of biogenic amines

Answer 18

serotonin, histamine, catecholamines (dopamine, epinephrine, norepinephrine)

Question 19

what are examples of neuropeptides

Answer 19

TRH, vasopressin, oxytocin, substance P, cholecystokinin, endogenous opioid (enkephalins, endorphins), orexin

Question 20

describe acetylcholine; where is it found, stored, released

Answer 20

• most abundant NT in PNS, also found in CNS
• stored in synaptic vesicles once synthesized in cytosol
• action potentials trigger its release thru exocytosis

Question 21

what are the 2 types of acetylcholine receptors

Answer 21

nicotinic and muscarinic cholinergic receptors

Question 22

describe nicotinic cholinergic receptors

Answer 22

found in PNS (autonomic neurons on skeletal muscle cells) and CNS, ionotropic

Question 23

describe muscarinic cholinergic receptors

Answer 23

found on some effector organs for ANS, this is the dominant cholinergic receptor type found in CNS, metabotropic

Question 24

why are unique NT molecules considered unique

Answer 24

appear to function as neurotransmitters but are not stored in synaptic vesicles nor released by exocytosis

Question 25

what are neuropeptides

Answer 25

short chains of amino acids made in rough endoplasmic reticulum, and packed into secretory vesicles by Golgi, most are hormones

Question 26

what does oxytocin regulate

Answer 26

uterine contraction and milk flow

Question 27

what does cholesystokinin regulate

Answer 27

gall bladder contraction

Question 28

what does antidiuretic hormone (vasopressin) regulate

Answer 28

kidney output

Question 29

what is orexin involved in

Answer 29

sleep-wake cycle

Question 30

what are endocannabinoids, what are they made by, function

Answer 30

unique NTs, made in neurons from membrane phospholipids but their function is still unknown

Question 31

when is glutamate released and the classes of receptors it binds to

Answer 31

at excitatory synapses in CNS; NMDA, APA, Kainate receptors

Question 32

when is GABA released and the classes of receptors it binds to

Answer 32

at inhibitory synapses in CNS; GABA A & C (ionotropic), GABA B (metabotropic)