Electrical signalling lecture 2 - Membrane potential, Neurotransmission and ligand gated channels

Question 1

What are inotropic glutamate receptors ?

Answer 1

ligand-gated ion channels

Question 2

where are inotropic glutamate receptors found ? And what do they do ?

Answer 2

at excitatory synapses allowing Na+/Ca2+ into post synaptic cell leading to depoarisation. they are less selective than voltage gated ion channels.

Question 3

How many domains do inotropic glutamate receptors exhibit ? Topology ?

Answer 3

3 + 1/2 (tetrameric) - inverted pore topology

Question 4

What are GABAa receptors ? how many domains ?

Answer 4

ligand-gated ion channels (pentameric)

Question 5

What are GABAa receptors known as ? and why ?

Answer 5

Cys-loop receptors because they have disulphide bridge in their extracellular ligand binding domain

Question 6

Where are GABAa receptors found ? what do they do ?

Answer 6

at inhibitory synapses allowing Cl- into post synaptic cell making it harder for depolarisation (hyper polarise) i.e they are inhibitory

Question 7

What are nicotinic acetyl choline receptors ?

Answer 7

ligand-gated ion channels

Question 8

What are nicotinic acetyl choline receptors also known as ?

Answer 8

Cys-loop receptors

Question 9

What are nicotinic acetyl choline receptors found ? and what do they do ?

Answer 9

excitatory synapses and neuromuscular junction, allowing Na+ into the post synaptic cell or muscle cell

Question 10

What extra step occurs at the neuromuscular receptor?

Answer 10

gated release of calcium ions into sarcoplasm from SR due to action potential travelling dow t tubules leading ultimately to contraction