Lecture 4: Chemical Synaptic Transmission: Recycling and Reuptake

Question 1

Heuser & Reese (1973) experiment significance

Answer 1

showed recycling occurs by using horseradish peroxidase to label vesicles

Question 2

Yamashita et al (2005, 2010) experiment significance

Answer 2

after stimulation of a presynaptic neuron, capacitance of the presynaptic membrane does up

Question 3

synaptophysins function

Answer 3

marks changes in acidity (fluorescent pH marker)
- light up when acidity goes down & NT is released from vesicle

Question 4

Royle (2012) and Granseth (2006) experiments significance

Answer 4

used synaptophysins to measure vesicle fusion; stuck it to the vesicle by attaching it to a vesicular SNARE

Question 5

SNAP & NSF function in clathrin-mediated endocytosis

Answer 5

keep vesicular proteins together as they move to the perisynaptic region to be endocytosed

Question 6

adaptor proteins in endocytosis

Answer 6

AP-2, Stonin, AP-180

Question 7

adaptor proteins function in clathrin-mediated endocytosis

Answer 7

help coordinate & recruit clathrin monomers

Question 8

clathrin monomer function in clathrin-mediated endocytosis

Answer 8

form a cage, invaginating the membrane

Question 9

dynamin rings function in clathrin-mediated endocytosis

Answer 9

‘cut’ the vesicle in a GTP-dependent manner

Question 10

Auxilin, Hsc70, synaptojanin function in clathrin-mediated endocytosis

Answer 10

support removal of clathrin & ready the synaptic vesicle for endosomal entry

Question 11

first step for clathrin-mediated endocytosis of exhausted synaptic vesicles

Answer 11

adaptor proteins connect clathrin to vesicular membrane

Question 12

second step for clathrin-mediated endocytosis of exhausted synaptic vesicles

Answer 12

clathrin triskelia assemble into a coat, curving membrane to form coated pit

Question 13

third step for clathrin-mediated endocytosis of exhausted synaptic vesicles

Answer 13

assembled clathrin cage constricts lipid stalk connecting two membranes

Question 14

fourth step for clathrin-mediated endocytosis of exhausted synaptic vesicles

Answer 14

dynamin ring forms and pinches off lipid stalk

Question 15

fifth step for clathrin-mediated endocytosis of exhausted synaptic vesicles

Answer 15

coated vesicle is translocated by actin filaments

Question 16

sixth step for clathrin-mediated endocytosis of exhausted synaptic vesicles

Answer 16

Hsc70 & auxilin uncoat vesicle

Question 17

acetylcholinesterase reaction

Answer 17

acetylcholine –> acetate + choline

Question 18

where does acetylcholinesterase work

Answer 18

in synaptic cleft

Question 19

how is choline brought back into presynaptic membrane

Answer 19

via transporters, often Na+ co-transporters

Question 20

acetylcholine vesicular transporter

Answer 20

vAChT

Question 21

how is glutamine brought back into the presynaptic membrane for glutamate

Answer 21

via transporters
- SN1 –> SAT2

Question 22

glutamine synthesis

Answer 22

glutamate –> glutamine + phosphate

Question 23

where does glutamine synthesis usually occur

Answer 23

astrocytes

Question 24

glutaminase reaction

Answer 24

glutamine + phosphate –> glutamate

Question 25

where does glutaminase reaction occur

Answer 25

in presynaptic terminal

Question 26

glutamate vesicular transporter

Answer 26

VGLUT

Question 27

how is glutamine brought back into presynaptic membrane for GABA

Answer 27

via GAT (Na+ co-transporter)

Question 28

how is GABA broken down

Answer 28

via multiple pathways via mitochondrial enzymes

Question 29

GABA synthesis

Answer 29

glucose --> glutamate --> GABA

Question 30

glutamic acid decarboxylase (GAD) function

Answer 30

completes the final step of GABA synthesis

Question 31

GABA vesicular transporter

Answer 31

VIAAT