Glutamine

Question 1

For a molecule to be regarded as an NT, what must there be regarding it in the presynaptic neuron?

Answer 1

It itself must be present, as well as the mechanisms for its synthesis (enzymes etc)

Question 2

For a molecule to be regarded as an NT, what must there be regarding it on the postsynaptic neuron?

Answer 2

Receptors to which the NT can bind

Question 3

What are the three criteria for defining a NT?

Answer 3

Present in the presynaptic neuron
Capable of being released
Postsynaptic receptors to which it can bind

Question 4

What kind of NT is glutamate?

Answer 4

An AA transmitter

Question 5

What is the main excitatory NT in the CNS?

Answer 5

Glutamate

Question 6

What is glutamate synthesised from?

Answer 6

Glutamine

Question 7

What is glutamate reuptaken by?

Answer 7

Excitatory AA transporters

Question 8

What other molecule can activate glutamate receptors?

Answer 8

Aspartate

Question 9

What is excitotoxicity?

Answer 9

Too much signalling that leads to cell death

Question 10

Where is glutamine first found in the glutamate synthesis pathway?

Answer 10

In glial cells

Question 11

What first happens to glutamine in the glutamate synthesis pathway?

Answer 11

It is transported out of glial cells via glutamine transporters

Question 12

Which enzyme converts glutamine to glutamate in the glutamate synthesis pathway?

Answer 12

Glutaminase

Question 13

Where is glutaminase found?

Answer 13

In nerve cells

Question 14

Which molecule helps glutamate be taken up into synaptic vesicles?

Answer 14

Vesicular glutamate transporters

Question 15

In which cells are EAATs found?

Answer 15

Presynaptic neurons and glial cells

Question 16

What are the two main classes of NT receptors?

Answer 16

Ionotropic and metabotropoic

Question 17

What are ionitropic receptors?

Answer 17

Ligand gated ion channels

Question 18

What type of receptor are metabotropic receptors?

Answer 18

G protein coupled receptors

Question 19

What are the three classes of ionotropic receptor?

Answer 19

NMDA, AMPA, KAINATE

Question 20

What are the three classes of metabotropic receptor?

Answer 20

Group I, Group II, Group III

Question 21

What kind of ion channel does NMDA, AMPA, KAINATE all form?

Answer 21

tetrameric ligand gated ion channels

Question 22

Which subunit must an NMDA receptor have?

Answer 22

GluN1

Question 23

What separates the different groups of metabotropic receptors?

Answer 23

The second messengers they couple to

Question 24

Which second messenger does Group 1 couple to?

Answer 24

G alpha Q

Question 25

Which second messenger does Group 2 couple to?

Answer 25

G alpha i o

Question 26

Which second messenger does group III couple to?

Answer 26

G alpha i o

Question 27

How does glutamate bind so many receptors?

Answer 27

Not a rigid molecule, can adopt different conformations

Question 28

What is present in the middle of the ionotropic subunits?

Answer 28

An ion channel pore

Question 29

Which subunits of an ionotropic receptor are transmembrane?

Answer 29

1, 3, 4

Question 30

Which subunits of an ionotropic receptor are not transmembrane?

Answer 30

2

Question 30

Which subunit segment is facing inwards to the ion channel in a ionotropic glutamate receptor?

Answer 30

2

Question 31

Which receptor can be homomeric?

Answer 31

AMPA

Question 32

Which ions are an AMPA receptor permeable to?

Answer 32

K+ and Na+

Question 33

What is the direction of K+ through an AMPA receptor?

Answer 33

Leaving the cell

Question 34

What is the direction of Na+ through an AMPA receptor?

Answer 34

Entering the cell

Question 35

Agonists of AMPA receptor?

Answer 35

glutamate, AMPA, KA

Question 36

Antagonists of AMPA receptor?

Answer 36

NBQX (competitive), GYKI (non-competive)

Question 36

What ions are NMDA receptors permeable to?

Answer 36

Ca2+, Na+, K+

Question 37

What is the direction of K+ through an NMDA receptor?

Answer 37

leaving the cell

Question 38

What is the direction of Ca2+ and Na+ through an NMDA receptor?

Answer 38

Entering the cell

Question 39

What kind of gated is an NMDA receptor?

Answer 39

voltage and ligand

Question 39

Which receptor requires a co-agonist?

Answer 39

NMDA

Question 40

What co-agonists do an NMDA receptor require?

Answer 40

Glycine or serine

Question 41

Why can a fast and slow time course be observed on the postsynaptic EPSP?

Answer 41

AMPA are fast, NMDA are slow and glutamate binds both

Question 42

Meaning of a dual gating receptor?

Answer 42

both ligand and voltage sensitive

Question 43

Which molecule blocks a NMDA receptor at resting potentian?

Answer 43

Mg2+

Question 44

What does depolarisation do to the NMDA receptor?

Answer 44

Relieves the MG2+ block from the ion pore

Question 45

Which ion are NMDA receptors highly permeable to?

Answer 45

Ca2+

Question 46

WHat speed of excitation are metabotropic receptors involved in?

Answer 46

slow

Question 47

Which molecules are NMDA receptor ion channel blockers?

Answer 47

Ketamine and memantine

Question 48

What happens when glutamate binds to an mGluR presynaptically?

Answer 48

G beta gamma subunits dissociate and close a calcium ion channel (stops Ca2+ from entering), preventing release of an NT

Question 49

What happens when glutamate binds to an mGluR postsynaptically?

Answer 49

G beta gamma subunits dissociate and close a potassium ion channel (stops K+ from leaving), leads to a slow depolarisation

Question 50

What can mGluR affect in terms of calcium?

Answer 50

Its intracellular release

Question 51

What do group 1 mGluRs do?

Answer 51

produce slow depolarisation and release Ca2+ from intracellular stores

Question 52

What do group 2/3 mGluRs do?

Answer 52

Inhibit glutamate and other transmitters release