W19/L3: Chemical transmission Flashcards Preview

6. Neuro > W19/L3: Chemical transmission > Flashcards

Flashcards in W19/L3: Chemical transmission Deck (16):
1

What are the functional requirements of a cell for neurotransmission?

Synthesis/storage
Release
Receptors
Inactivation

2

What initiates NA release?

Ca2+ influx

3

What is the pre-synaptic receptor for NA?

Alpha2 adrenoceptor

4

What enzyme metabolises NA?

MAO (monoamine oxidase)

5

What is the main process of NA inactivation?

Neuronal uptake (95%)
Extraneuronal uptake (5%)

6

What is the benefit of using reuptake as the mechanism of NA inactivation?

It mean the molecule can be re-used. It's "expensive" to have to manufacture new NA

7

CNS MoA of cocaine?

Blocks neuronal uptake of NA, dopamine and 5HT

(The dopaminergic effects are implicated in dependence

The 5HT effects are implicated in eurphoria)

8

How do indirectly-acting sympathomimetics act?

They displace the NA from the vesicle so it "leaks" out and acts on the adrenoceptors

9

What are some indirectly-acting sympathomimetics?

Amphetamine
Ephedrine

10

Are all NTs found all over the brain?

No some are widespread, but others are localised

11

Why is NO a unique NT?

It can't be made in advance and stored in vesicles, so it has to be manufactured "on demand"

12

What are the steps of catecholamine synthesis?

Tyrosine enters the cell

Converted to L-DOPA by tyrosine hydroxylase

Converted to Dopamine by dopa decarboxylase

Enters the vesicle

Converted to NA by dopamine-beta-hydroxylase

Converted to adrenaline by PENMT

13

What's an excitatory NT?

Glutamate

14

What's an inhibitory NT?

GABA

15

What sort of receptor is the NicR?

Excitatory ligand-gated ion channel

(causes Na+ influx)

16

What sort of receptor is the GABA-A receptor?

Inhibitory ligand-gated ion channel

(causes Cl- influx)