Neurotransmitters and pharmacology

Question 1

Classes of neurotransmitters?

Answer 1

Amino acids, amines and neuropeptides.

Question 2

When neurotransmitter binds to the post synaptic receptor, what does this result in?

Answer 2

Action potential in the post synaptic neurone. Sodium influx in post synaptic neurone.

Question 3

Explain neurotransmitter release

Answer 3

Docking of vesicle containing neurotransmitter in synaptic zone. Ca2+ entry leading to membrane fusion and exocytosis

Question 4

How does alpha latrotoxin act as a neurotoxin?

Answer 4

Activates calcium channels. Massive neurotransmitter release resulting in muscle cramping.

Question 5

How does botulinum toxin act as a neurotoxin?

Answer 5

Inhibits vesicle exocytosis. Paralysis, no muscle contraction.

Question 6

Two types of post synaptic receptors?

Answer 6

Ion channel linked receptor and g protein-coupled receptor.

Question 7

Nature of response in post synaptic ion channel linked receptors?

Answer 7

Fast response.

Question 8

Nature of response in post synaptic g protein-coupled receptors?

Answer 8

Slow response.

Question 9

What is the main neurotransmitter and post synaptic neurotransmitter receptor in the CNS?

Answer 9

Glutamate and GABA receptor.

Question 10

What is the main neurotransmitter and post synaptic neurotransmitter receptor in the NMJ?

Answer 10

Acetylcholine and nicotinic receptors.

Question 11

Examples of g protein coupled receptors?

Answer 11

Seretonin receptors, Dopamine receptors, noradrenaline receptors,
Muscarinic receptors (acetylcholine).

Question 12

Main Inhibitory neurotransmitters in CNS?

Answer 12

GABA and glycine.

Question 13

Main excitatory neurotransmitter in CNS?

Answer 13

Glutamate.

Question 14

Are nicotinic receptors excitatory?

Answer 14

Nicotinic receptors are always excitatory.

Question 15

How can a receptor excite a neurone?

Answer 15

Lead to sodium influx.

Question 16

How can a receptor inhibit a neurone?

Answer 16

Lead to hyperpolarisation. With GABA and glycine its a chloride influx.

Question 17

What are the two types of glutamate receptors?

Answer 17

AMPA and NMDA.

Question 18

NMDA vs AMPA in terms of influx of ions?

Answer 18

NMDA receptors activation results in the influx of calcium ions in addition to the sodium. AMPA is just sodium.

Question 19

NMDA vs AMPA in terms of function?

Answer 19

NMDA is responsible for slow component of excitatory transmission while AMPA is responsible for majority of fast excitatory synapses.

Question 20

What do glutamate receptors require to work?

Answer 20

Glycine bound to receptor.

Question 21

What cell is involved in the reuptake of neurotransmitter?

Answer 21

Glial cell.

Question 22

What are seizures associated with?

Answer 22

Excess glutamate.

Question 23

Why is glutamine synthetase important?

Answer 23

Glutamate to glutamine conversion in glial cells. Reduces excess levels of glutamate in synapse and so no seizures.

Question 24

Explain a synaptic transmission involving glutamate?

Answer 24

Glutamate reversibly binds postsynaptic receptors. Rapid uptake of glutamate by excitatory amino acid transporters on presynaptic terminal and glial cell. Glutamate enzymatically modified by glutamine synthetase to glutamine in glial cells

Question 25

How is GABA synthesised?

Answer 25

GABA synthesised by decarboxylation of glutamate by glutamic acid decarboxylase (GAD).

Question 26

Explain a synaptic transmission involving GABA?

Answer 26

GABA reversibly binds post-synaptic receptors. Rapid uptake of GABA by GABA transporters on presynaptic terminal and glial cell. GABA enzymatically modified by GABA-transaminase to succinic semialdehyde in glial cells.