CH. 8 GABA

Question 1

what does GABA stand for

Answer 1

gama-aminobutyric acid

Question 2

what is GABA’s function

Answer 2

primary inhibitory transmitter in the brain

Question 3

what is another example of and inhibitory transmitter? where was it found?

Answer 3

glycine
back of the brain

Question 4

what neurons use GABA?

Answer 4

medium spiny neurons in striatum
basal ganglia in general
projection neurons intermixed within monoamine cell groups
interneurons

Question 5

what is the main role of GABA transmission

Answer 5

filter information and regulate firing patterns
disinhibition

Question 6

what can happen to the body with reduced GABA activity?

Answer 6

seizures

Question 7

what is an example of a disinhibition connection in the brain

Answer 7

pallidum is always firing GABAergic signals to motor region
ventral striatum activation sends GABA signal to pallidum, allowing for activation of motor region

Question 8

what is the precursor to GABA

Answer 8

glutamate

Question 9

what is the enzyme that synthesizes glutamate to GABA

Answer 9

glutamate decarboxylase (GAD)

Question 10

what is the enzyme that moves GABA into vesicles?

Answer 10

vesicular GABA transporter (VGAT)

Question 11

true or false; some vesicles contain varying amounts of GABA and another NT

Answer 11

true

Question 12

what is GAT1 through 3

Answer 12

GABA’s reuptake transporter

Question 13

what GABA reuptake transporter is found on the presynaptic terminal?

Answer 13

GAT-1

Question 14

what GABA reuptake transporter is found on the astrocytes?

Answer 14

all three (GAT1-3)

Question 15

what is the glial reuptake process of GABA

Answer 15

metabolized to glutamate and succinate
metabolized back to glutamine
released by astrocyte back to the presynapse

Question 16

what enzyme metabolizes GABA to glutamate?

Answer 16

GABA aminotranferase (GABA-T)

Question 17

what are the two main type of GABA receptors?

Answer 17

GABA-A
GABA-B

Question 18

what kind of receptor is GABA-A

Answer 18

ionotropic

Question 19

what does the GABA-A receptor do?

Answer 19

opens when activated
allows inflow of Cl-
hyperpolarizes the cell

Question 20

how many subunits do GABA-A receptors have?

Answer 20

5, different combinations of 4 different types

Question 21

what kinds of sites do GABA-A receptors have

Answer 21

GABA binding site
inside channel pore
allosteric binding site
neurosteroids binding site

Question 22

agonist that binds to the GABA binding site

Answer 22

muscimol

Question 23

what is muscimol

Answer 23

psychedelic mushrooms

Question 24

Competitive antagonist that binds to the GABA binding site

Answer 24

bicuculline

Question 25

non-competitive antagonist that binds to inside of channel pore

Answer 25

picrotoxin

Question 26

what does picrotoxin do? what is the effect?

Answer 26

physically blocks the ion pore channel induces seizures

Question 27

positive allosteric modulator that sticks to the allosteric binding site of the GABA-A receptor

Answer 27

benzodiazepine (BDZ) barbituates

Question 28

BDZ drug example

Answer 28

diazepam

Question 29

store name for diazepam

Answer 29

valium

Question 30

barbituate example

Answer 30

phenobarbitol

Question 31

BDZ effects

Answer 31

reduces anxiety sleep/sedation reduces REM sleep

Question 32

what molecule acts as a similar way to BDZ but binds in a different spot on the GABA-A receptor?

Answer 32

neurosteroids

Question 33

what other molecule can bind at the BDZ site? what is it's effect?

Answer 33

inverse agonist impedes effects of GABA on the channel

Question 34

what kind of receptor is the GABA-B receptor?

Answer 34

metabotropic

Question 35

how many subunits does the GABA-B receptor have?

Answer 35

2

Question 36

how does the GABA-B receptor work on the postsynapse

Answer 36

opens K+ channel and inhibiting cAMP formation

Question 37

what is the function of GABA-B receptors on the presynapse?

Answer 37

autoreceptors and heteroreceptors

Question 38

GABA-B receptor agonist

Answer 38

baclofen

Question 39

baclofen function

Answer 39

muscle relaxant experimental alcoholism treatment

Question 40

GABA-B receptor antagonist

Answer 40

saclofen

Question 41

saclofen function

Answer 41

convulsant used in research