Exam 3: Glutamate and GABA

Question 1

glutamate is stored and presumably release as a ___

Answer 1

co-transmitter

Question 2

glutamate is synthesized from _____ by ______ which requires _____

Answer 2

glutamine by glutaminase

needs ATP for energy

Question 3

3 vesicular glutamate transporters

Answer 3

VGLUT1, VGLUT2, VGLUT3

move glutamate into synaptic vesicles

Question 4

glutamate as a co-transmitter

Answer 4

can store in separate vesicles or the same one - may be released at diff sites

DA-glutamate neusons of VTA release DA from varicosites and glutamate from terminals
- reinforcing properties of drug use

Question 5

astrocytes

Answer 5

take up glutamate from extracellular space, express glutamate receptors, and respond to activation of those receptors

Question 6

gliotransmission

Answer 6

astrocytes release glutamate

Question 7

after glutamate is released into synaptic cleft, it is rapidly removed by

Answer 7

excitatory amino acid transporters (EAAT1-EAAT5) on cll membranes
also take up aspartate

Question 8

how do astrocytes convert glutamate to glutamine

Answer 8

glutamine synthetase

Question 9

3 types of ionotropic receptors

Answer 9

NMDA, AMPA, Kainate

excitatory - depolarize postsynaptic cell

Question 10

types of metabotropic receptors

Answer 10

mGluR - 3 classes

Question 11

AMPA and Kainate receptors are depolarized by

Answer 11

flow of sodium ions

Question 12

NMDA receptors allow what ion/ions to flow through

Answer 12

Ca and Na

Ca activates a second messenger

Question 13

NMDA receptors - how the work

Answer 13

when at resting potential Mg blocks channel pore, when depolarized Mg ions dissociate
to open channel: BOTH glutamate and glycine or D-serine must bind at the SAME time

Question 14

glutamate system in brain

Answer 14

cortico-cortical pathway - between thalamus and cortex

cortico-striatal pathway- movement, basal ganglia

implicated in learning and memory, facilitated movement

Question 15

AMPA and NMDA receptors implicated in

Answer 15

learning and memory

Question 16

ampakines

Answer 16

enhance action of AMPA receptors by reducing rate of deactivation or desensitization

Question 17

influx of Ca through NMDA activates protein kinases leading to more

Answer 17

AMPA receptors being inserted in ost synaptic membran
inc sensitivity of postsynaptic neuron to glutamate
facilitates learning and memory

Question 18

high levels of glutamate can be

Answer 18

toxic to nerve cells

- prolonged depolarization leads to eventual damage or death

Question 19

major inhibitory AA transmitters

Answer 19

GABA

glycine

Question 20

can GABA be a co-transmitter like glutamate?

Answer 20

yes

Question 21

GABA is made from ____ and catalyzed by____

Answer 21

made form glutamate

catalyzed by glutamic acid decarboxylase (GAD)

Question 22

what moves GABA and glycine into vesicles

Answer 22

VGAT / VIAAT

Question 23

GABA is removed from synapse by

Answer 23

GAT-1, GAT-2, GAT-3

Question 24

what is GABA metabolized to

Answer 24

glutamate and succinate by GABA aminotransferase (GABA-T)

Question 25

GABA A receptor

Answer 25

ionotropic

each receptor has 5 sub units in various combinations

Question 26

GABA B receptor

Answer 26

metabotropic

Question 27

GABA A receptor channels allow what ion to move into cell, what happens

Answer 27

chloride

causes hyperpolarization and inhibition of postsynaptic cell

Question 28

what are GABA A receptors sensitive to

Answer 28

CNS-depressant drugs with antianxiety, sedativem and anticonvulsant properties
- subunit composition of the receptor in important

Question 29

benzodiazepines (BDZs) on GABA A receptors

Answer 29

sensitivity requires presence of gamma subunit (y)
sedating effects of BDZs require a1 subunits
anxiolytic actions require a2 subunits

ethanol has similar properties to GABA A receptor

Question 30

GABA B receptor effect in postsynaptic cells

Answer 30

inhibit cAMP formation and K+ channel opening

Question 31

role of GABA B receptors

Answer 31

learning and memory
anxiety
depression - like behaviors
responses to drugs of abouse