Lecture 11 Synaptic Transmission Part 2

Question 1

AP blocks ________ and prolongs AP and the amount of ________ that can enter

Answer 1

K+, Ca2+

Question 2

When AP blocks K+ and prolongs the action potential and the amount of Ca2+ that can enter, what 2 things can happen?

Answer 2

leads to more quanta

Correlates perfectly with number of fused vesicles in EM.

Question 3

Name 2 events in fusion of a transport vehicle.

Answer 3

1) transport vehicle must recognize the correct target membrane
2) the vesicle and target membrane must fuse

Question 4

Why must the target membrane and vesicle fuse?

Answer 4

So content of vesicle can be delivered to organelle or into synaptic cleft.

Question 5

Proteins involved in synaptic release have what functions?

Answer 5

• Restrain vesicles
• Target and dock vesicles to active zone
• Allow fusion/exocytosis
• Recycle

Question 6

________ tethers vesicles to the cytoskeleton

Answer 6

Synapsin

Question 7

_______ phosphorylates synapsin to mobilize _______ pool

Answer 7

CaMKII, reserve

Question 8

Groups of proteins that promote fusion of the vesicle and presynaptic membrane

Answer 8

SNAp Receptors

Question 9

Describe the 3 main players in the SNARE hypothesis?

Answer 9

v-SNARE (Synaptobrevin): sits in vesicle
t-SNARE (Syntaxin):presynaptic membrane
Synaptotagmin-calcium sensor

Question 10

What is munc-18?

Answer 10

Part of SNARE, binds with syntaxin to inhibit SNARE complex formation

Question 11

What interacts with synaptotagmin and leads to fusion

Answer 11

Neurexins

Question 12

NSF and alpha-SNAP are responsible for _________. Bind SNARE, uitilizes ATP to break apart complexes after fusion

Answer 12

priming

Question 13

Is Synaptotagmin a SNARE?

Answer 13

no

Question 14

Synapsins are regulated by what 2 kinases?

Answer 14

cAMP-dependent kinase and Ca2+/Calmodulin dependent kinases

Question 15

Rab proteins are small ________ binding proteins

Answer 15

GTP

Question 16

Name some functions of rab proteins

Answer 16

vesicle formation, vesicle movement, fusion (interacts with vSNARES to initiate fusion)

Question 17

Synaptotagmin binds _________ and __________(in a calcium dependent manner)

Answer 17

clathrin, phospholipids

Question 18

Clathrin and dynamin are involved in ___________.

Answer 18

endocytosis

Question 19

What does clathrin do?

Answer 19

forms coated pits

Question 20

What does dynamin do?

Answer 20

pinches off coated vesicle

Question 21

________ consist of 4-5 subunits that open a pore upon receptor binding.

Answer 21

Multimers

Question 22

Direction of PSP is determined by what?

Answer 22

ionic identity

equilibrium/reversal potential

Question 23

An EPSP has a reversal potential more ________ than AP threshold.

Answer 23

positive

Question 24

An IPSP has a reversal potential more ________ than AP threshold

Answer 24

negative

Question 25

Excitatory input is due to release of glutamate and is permeable to both ___ and ____.

Answer 25

Na+ and K+

Question 26

Inhibitory input is due to release of GABA and is permeable to _____.

Answer 26

Cl-

Question 27

A synaptic potential can be _________ and ________.

Answer 27

depolarizing, inhibitory

Question 28

Ecl- is more ___________ than AP threshold.

Answer 28

hyperpolarized

Question 29

Shunting inhibition is an increase in _______________.

Answer 29

resting conductance

Question 30

Post synaptic graded responses are summed in the _______.

Answer 30

soma