Neurotransmitters

Question 1

What are the 3 stages of synaptic transmission?

Answer 1

1. Biosynthesis, packaging and release of neurotransmitter
2. Receptor action
3. Inactivation

Question 2

What calcium concentration is required intracellularly to cause the release of neurotransmitter?

Answer 2

200uM

Question 3

How do G-protein coupled receptors work?

Answer 3

• A neurotransmitter (or drug) binds to the G-protein coupled receptor
• They then link to a G-protein which then mediates the response

Question 4

How do ion channel receptors work?

Answer 4

A molecule will bind to the ion channel and cause a conformational change to the ion channel, allowing the influx or efflux of certain ions

Question 5

Are ion channel-linked receptors relatively fast or slow?

Answer 5

Fast, u to m seconds

Question 6

Are G-protein linked receptors relatively fast or slow?

Answer 6

Slow, seconds to minutes

Question 7

What are examples of ion channel-linked receptors?

Answer 7

• Nicotinic cholinergic receptors (nACHr)
• Glutamate (GluR)
• GABA (GABAR)
• Glycine (GlyR)

Question 8

What does stimulation of GABA and glycine receptors lead to?

Answer 8

Influx of chlorine ions (hyperpolarisation), Inhibitory NTR

Question 9

What does stimulation of glutamate receptors lead to?

Answer 9

Influx of sodium ions (depolarisation), Excitatory NTR

Question 10

What are the 2 types of glutamate receptor?

Answer 10

AMPA receptors - Na+ ion channel, rapid glutamate response
NMDA receptors - Ca2+ & Na+ ion channel, slower component for glutamate response, need something to depolarise cell first, coincidence detectors

Question 11

What occurs to glutamate in glial cells?

Answer 11

Glutamine synthetase converts glutamate into glutamine

Question 12

What can cause seizures?

Answer 12

There is an excessive amount of glutamate which causes excitation or if GABA is not working optimally to counteract the glutamate excitation, the action potential is constantly fired causing a seizure