GABA Neurotransmission

Question 1

What are the potential subunits of the glycine receptor?

Answer 1

Alpha 1-4 and beta 1 (although no alpha 4 found in humans)

Question 2

The anion pore of glycine receptors is selective for which ion?

Answer 2

Cl- (how it mediates inhibition)

Question 3

What molecules synthesise GABA?

Answer 3

Glutamate Decarboxylase (GAD) - GAD67 throughout cell and GAD65 in nerve endings

Question 4

What are the names of the transporters that transport GABA into cells?

Answer 4

GAT1 and GAT3

Question 5

VGAT transports GABA and which other neurotransmitter into vesicles?

Answer 5

Glycine

Question 6

How is GABA signalling terminated?

Answer 6

Diffusion and uptake by GATs

Question 7

Co-activation of GABA A and GABA B receptors produces…

Answer 7

long lasting biphasic IPSPs

Question 8

GABA B receptors are commonly found on which side of the synapse?

Answer 8

Presynaptically - to reduce glutamate release

Question 9

What happens during paired pulse depression?

Answer 9

Activation of presynaptic GABA B receptors negatively coupled to voltage gated ion channels leads to decreased Ca2+ entry to the presynaptic cell. This means that the conditioned (2nd) stimulus results in reduced Ca2+-dependent exocytosis. Less GABA is therefore released.