Neurotransmitters And Their Receptors

Question 0

What is caused by excess glutamate?

Answer 0

Excitotoxicity (ischemia, epilepsy, hypoglycaemia or trauma)

Question 1

What is the main excitatory neurotransmitter in the brain?

Answer 1

Glutamate (0.5 synapses)

Question 2

Which neurotransmitter produces inhibitory postsynaptic potentials (IPSP)?

Answer 2

GABA

Question 3

What defines a neurotransmitter as a bionic amine?

Answer 3

Possessing an amine side chain

Question 4

Name the 4 main catecholamines and what they were derived from.

Answer 4

L-DOPA, dopamine, noradrenaline and adrenaline all from tyrosine

Question 5

Which 2 neurotransmitters are involved in reward pathways?

Answer 5

Dopamine and serotonin

Question 6

What are the main functions of peptide hormones?

Answer 6

Modulate pain, emotions, stress levels and appetite

Question 7

What is the main peptide neurotransmitter involved in pain and how is this pain reduced?

Answer 7

Substance P, release is inhibited by opiods

Question 8

How is acetylcholine removed from the synapse?

Answer 8

Via the enzyme, acetylcholinesterase

Question 9

Which neurotransmitters are reuptaken, either the glia or the neurone?

Answer 9

GABA, glutamate and serotonin

Question 10

What is the mechanism for the removal of peptide hormones from the synapse?

Answer 10

They diffuse away from the synapse

Question 11

What are the two main neuroreceptors?

Answer 11

Metabotropic (GPCR) and ionotropic (LGIC)

Question 12

There are two types of LGIC, what are they?

Answer 12

Cationic allowing positive ion influx and anionic allowing negative ion influx

Question 13

GPCR are characterised by what structural aspect?

Answer 13

Their single polypeptide, 7 transmembrane helices

Question 14

The activation of a G protein by the binding of a neurotransmitter leads to what?

Answer 14

A signalling cascade of amplification

Question 15

Which ionotropic receptors are pentamers?

Answer 15

GABA, glycine and acetylcholine

Question 16

What is the structure of nicotinic acetylcholine receptors?

Answer 16

Must have at least 2 alpha subunits. Usually 3 alpha and 2 beta

Question 17

Why is it less common for LGIC to allow passage of calcium?

Answer 17

Because calcium is large, the receptor much posses the alpha-7 domain

Question 18

How many transmembrane helices does a subunit have if it’s C terminal in intracellular?

Answer 18

3 helices, the 2nd being a pore loop

Question 19

If a subunit has 4 transmembrane helices, where are the N and C terminals situated?

Answer 19

Both outside if the cell

Question 20

LGIC subunits have transmembrane helices, which helix is most important and why?

Answer 20

2nd as it controls ion entry

Question 21

What are the different types if glutamate receptors?

Answer 21

AMPA, NMDA and kainate

Question 22

How many subunits do glutamate ionotropic receptors have?

Answer 22

4, tetrameric

Question 23

How is AMPA formed?

Answer 23

2 gluR1 subunits and 2 gluR2 subunits

Question 24

What change is made to an AMPA receptor to allow calcium movement?

Answer 24

One gluR2 is replaced by a gluR1

Question 25

Why does the glutamate NMDA receptor require a high frequency stimulant?

Answer 25

Because it is ordinarily block by magnesium

Question 26

How does glycine enhance glutamate effects?

Answer 26

Binds to NMDA receptors and acts as a co agonist

Question 27

What must the ionotropic GABAa receptors posses to work?

Answer 27

At least 2 beta subunits

Question 28

The binding of GABA to GABAa allows what ion to flow? What does this cause?

Answer 28

Chlorine, causing hyperpolarisation

Question 29

What affect does picrotoxin have on GABAa receptors?

Answer 29

Binds and prevents the movement of choline, reducing the inhibitory effects

Question 30

What drug can be used to prevent GABA binding to GABAa receptors?

Answer 30

Benzodiazepines

Question 31

In meta preppie receptors, where is the G protein situated?

Answer 31

Between helices 5 and 6 and near the C terminal

Question 32

There are metabotropic receptors for which neurotransmitters?

Answer 32

Dopamine, NA, adrenaline, histamine, serotonin, glutamate, GABAb and muscarinic

Question 33

There are many metabotropic receptor subtypes for each neurotransmitter, why?

Answer 33

Because of the specific G protein bound

Question 34

What G protein is bound the the beta-adrenergic receptor that binds NA?

Answer 34

Gs

Question 35

Which G protein is bound to the mGluR metabotropic receptor for glutamate?

Answer 35

Gq

Question 36

Which G protein is bound the the D2 metabotropic dopamine receptor?

Answer 36

Gi