4. Neurotransmitters

Question 1

what was the first neurotransmitter to be discovered

Answer 1

acetylcholine

Question 2

how is acetylcholine synthesised

Answer 2

Aectyl coA + choline → acetylcholine

by action of choline acetyl transferase

Question 3

name the two types of acetylcholine receptors

Answer 3

nicotinic

muscarinic

Question 4

where do u find nicotinic receptors

Answer 4

neuromuscular junctions, brain, autonomic nerves

Question 5

where do u find muscarinic receptors

Answer 5

smooth muscle, exocrine glands, brain

Question 6

how is acetylcholine function affected in Alzheimers disease

Answer 6

cholinergic neurons die early

- important in memory and attention

Question 7

what is a treatment for AD

Answer 7

acetylcholinesterase inhibitors- more time for Ach to bind to receptors

Question 8

give two examples of catecholamines

Answer 8

dopamine and norepinephrine

Question 9

what a catecholamines synthesised from

Answer 9

tyrosine

Question 10

what are the two families of dopamine receptors

Answer 10

D1-like = D1 & D5
D2-like= D2,D3,D4

Question 11

what are D1-like receptors coupled to

Answer 11

stimulatory G-proteins

Question 12

what are D2-like receptors coupled to

Answer 12

inhibitory G-proteins

Question 13

what happens to dopamine in Parkinson’s diease

Answer 13

degeneration of dopaminergic neurons= 50% depletion of dopamine

Question 14

how are motor symptoms of dopamine treated

Answer 14

L-dopa
-transported to the brain and converted to dopamine

dopa decarboxylase inhibitor
- prevents premature conversion of l-dopa to dopamine

Question 15

what is serotonin synthesised from

Answer 15

tryptophan

Question 16

what are the majority of serotonin receptors

Answer 16

14 g-protein coupled receptors

5-HT^3 → ligand gated ion channel

Question 17

name two amino acid neurotransmitters

Answer 17

Glutamate and GABA

Question 18

GABA receptors are inotropic, explain how this makes GABA inhibitory

Answer 18

GABA receptors are coupled to chloride channels, when GABA binds, chloride channels open and cl- enters the cell lowering the charge away from threshold potential

Question 19

what enzyme converts glutamate into GABA

Answer 19

glutamate decarboxylase

Question 20

what are the three different types of glutamate receptors- give a very brief description

Answer 20

NMDA receptor- binds many molecules

non-NMDA receptor- interacts only with glutamate

mGlut receptor- GPCR

Question 21

what removes astrocytes from the synapse

Answer 21

astrocytes

Question 22

where are peptide neurotransmitters most commonly used

Answer 22

hypothalamus

Question 23

what other molecules can act as neurotransmitters:

Answer 23

purines, histamine, nitric oxide