9/17 synaptic transmission

Question 1

what are the two types of neurotransmission

Answer 1

electrical and chemical

Question 2

what are the characteristics of electrical and chemical neurotransmission?

Answer 2

Question 3

What is the sequence of the chemical neurotransmission? what cause the fusion of NT vesicle at the presynaptic? What is Ca2+?

Answer 3

the binding of Ca2+ at the presynaptic cleft, where Ca2+ is a second messenger

Question 4

how is the NT at the postsynaptic cleft recycled or inactivated?

Answer 4

1. reuptake
2. diffuse away
3. enzymatically inactivated

Question 5

how or where is the NT synthesized in the presynaptic neuron?

Answer 5

food and soma of neurons

Question 6

There are 3 factors control the release of NT in response to presynaptic action potential?

Answer 6

1. Ca2+ dependent
2. quantal hypothesis (fixed amount of NT release each time)
3. NT release = (Ca2+)+(action potential), which means that increasing Ca2+ or action potential would increase the release of NT

Question 7

once the NT is released, the post-synaptic cleft must receive the NT

NT must somehow be inactivated at the end

Question 8

How many types of NT are there? and what are they?

Answer 8

4

choline esters - Ach (mAchR and nAchR)

biogenic amines - Dopamine, epinephrine, norepinephrine, serotonin

amino acids - glutamate, glycine, GABA

neuropeptides - ACTH, glucagon, endorphins

Question 9

EPSP has what kind of characteristics?

Answer 9

easier to fire action potential

the RP is closer to the threshold by have K+ out of cell and Na+ into the cell

Question 10

IPSP has what kind of characteristics?

Answer 10

harder to fire the action potential

making RB potential further away from the threshold

through K out of cell and Cl- into the cell

Question 11

what are the two types of neural summation?

Answer 11

spatial and temporal

Question 12

what is the spatial summation?

Answer 12

1. there are many pre-synaptic neurons fire at the same time, which causes potential to reach the threshold

Question 13

What is the temporal summation?

Answer 13

One neuron fires the potential over time until it reaches the threshold

Question 14

Two types of Ach receptors

Answer 14

nicotinic AchR

metabotropic AchR

Question 15

nicotinic Ach receptors is what type of receptor?

Answer 15

ionotropic

Ach bind to NAchR——Na+ and K+ influx and outflux——membrane depolarization——AP

Ex: skeletal muscles

Question 16

metabotropic (GPCR)

Ach binds to receptor——release of alpha-GTP from beta/gamma—-beta/gamma elicit a variety of response

Ex: auto NS