Cellular Response to APs

Question 1

Describe the alpha subunit of VG calcium channels

Answer 1

1 peptide
4 repeats
Pore forming region present
Cytoplasmic linkers

Question 2

Where are L type calcium channels present?

Answer 2

Heart
Smooth muscle
Lungs
Skeletal muscle

Question 3

Describe the process of neurotransmitter release

Answer 3

VG calcium channels open
Ca2+ enters and binds to synaptotagmin 
Brings vesicles close to membrane
SNARE complex makes a fusion pore
Transmitter released through the pore

Question 4

How many ACh have to bind to a nAChR to open it?

Answer 4

2

Question 5

Name a competitive blocker of nAChR

Answer 5

Curare

Question 6

Name a depolarising blocker of nAChR

Answer 6

Succinylcholine

Question 7

How does succinylcholine work as a depolarising blocker?

Answer 7

Maintains depolarisation therefore many of the Na+ channels are inactivated

Question 8

What are miniature end plate potentials?

Answer 8

Spontaneous release of vesicles when there is no AP

Only generate approx 1mV amplitude

Question 9

In myasthenia gravis, which receptors are targeted?

Answer 9

nAChRs

Question 10

What type of receptor are muscarinic receptors?

Answer 10

G protein coupled receptors

Question 11

Which channels regulate neurotransmitter release?

Answer 11

VG calcium channels