Glutamine 4.0

Question 3

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

Answer 3

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

Question 4

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

Answer 4

Receptors to which the NT can bind

Question 5

What are the three criteria for defining a NT?

Answer 5

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

Question 6

What kind of NT is glutamate?

Answer 6

An AA transmitter

Question 7

What is the main excitatory NT in the CNS?

Answer 7

Glutamate

Question 8

What is glutamate synthesised from?

Answer 8

Glutamine

Question 9

What is glutamate reuptaken by?

Answer 9

Excitatory AA transporters

Question 10

What other molecule can activate glutamate receptors?

Answer 10

Aspartate

Question 11

What is excitotoxicity?

Answer 11

Too much signalling that leads to cell death

Question 12

Where is glutamine first found in the glutamate synthesis pathway?

Answer 12

In glial cells

Question 13

What first happens to glutamine in the glutamate synthesis pathway?

Answer 13

It is transported out of glial cells via glutamine transporters

Question 14

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

Answer 14

Glutaminase

Question 15

Where is glutaminase found?

Answer 15

In nerve cells

Question 16

Which molecule helps glutamate be taken up into synaptic vesicles?

Answer 16

Vesicular glutamate transporters

Question 17

In which cells are EAATs found?

Answer 17

Presynaptic neurons and glial cells

Question 18

What are the two main classes of NT receptors?

Answer 18

Ionotropic and metabotropoic

Question 19

What are ionitropic receptors?

Answer 19

Ligand gated ion channels

Question 20

What type of receptor are metabotropic receptors?

Answer 20

G protein coupled receptors

Question 21

What are the three classes of ionotropic receptor?

Answer 21

NMDA, AMPA, KAINATE

Question 22

What are the three classes of metabotropic receptor?

Answer 22

Group I, Group II, Group III

Question 23

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

Answer 23

tetrameric ligand gated ion channels

Question 24

Which subunit must an NMDA receptor have?

Answer 24

GluN1

Question 25

What separates the different groups of metabotropic receptors?

Answer 25

The second messengers they couple to

Question 26

Which second messenger does Group 1 couple to?

Answer 26

G alpha Q

Question 27

Which second messenger does Group 2 couple to?

Answer 27

G alpha i o

Question 28

Which second messenger does group III couple to?

Answer 28

G alpha i o

Question 29

How does glutamate bind so many receptors?

Answer 29

Not a rigid molecule, can adopt different conformations

Question 30

What is present in the middle of the ionotropic subunits?

Answer 30

An ion channel pore

Question 31

Which subunits of an ionotropic receptor are transmembrane?

Answer 31

1, 3, 4

Question 32

Which subunits of an ionotropic receptor are not transmembrane?

Answer 32

2

Question 33

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

Answer 33

2

Question 34

Which receptor can be homomeric?

Answer 34

AMPA

Question 35

Which ions are an AMPA receptor permeable to?

Answer 35

K+ and Na+

Question 36

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

Answer 36

Leaving the cell

Question 37

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

Answer 37

Entering the cell

Question 38

Agonists of AMPA receptor?

Answer 38

glutamate, AMPA, KA

Question 39

Antagonists of AMPA receptor?

Answer 39

NBQX (competitive), GYKI (non-competive)

Question 40

What ions are NMDA receptors permeable to?

Answer 40

Ca2+, Na+, K+

Question 41

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

Answer 41

leaving the cell

Question 42

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

Answer 42

Entering the cell

Question 43

What kind of gated is an NMDA receptor?

Answer 43

voltage and ligand

Question 44

Which receptor requires a co-agonist?

Answer 44

NMDA

Question 45

What co-agonists do an NMDA receptor require?

Answer 45

Glycine or serine

Question 46

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

Answer 46

AMPA are fast, NMDA are slow and glutamate binds both

Question 47

Meaning of a dual gating receptor?

Answer 47

both ligand and voltage sensitive

Question 48

Which molecule blocks a NMDA receptor at resting potentian?

Answer 48

Mg2+

Question 49

What does depolarisation do to the NMDA receptor?

Answer 49

Relieves the MG2+ block from the ion pore

Question 50

Which ion are NMDA receptors highly permeable to?

Answer 50

Ca2+

Question 51

WHat speed of excitation are metabotropic receptors involved in?

Answer 51

slow

Question 52

Which molecules are NMDA receptor ion channel blockers?

Answer 52

Ketamine and memantine

Question 53

What happens when glutamate binds to an mGluR presynaptically?

Answer 53

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

Question 54

What happens when glutamate binds to an mGluR postsynaptically?

Answer 54

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

Question 55

What can mGluR affect in terms of calcium?

Answer 55

Its intracellular release

Question 56

What do group 1 mGluRs do?

Answer 56

produce slow depolarisation and release Ca2+ from intracellular stores

Question 57

What do group 2/3 mGluRs do?

Answer 57

Inhibit glutamate and other transmitters release