Weeks 4-6

Question 1

Resting state

Answer 1

All voltage gated Na+ and K+ closed.

Question 2

Depolarising phase

Answer 2

Voltage gated Na+ channel open.

Question 3

Repolarising phase

Answer 3

K+ channels open, Na+ closed

Question 4

Undershoot

Answer 4

K+ channels remain open, Na+ closed

Question 5

How do you distinguish between size of stimuli?

Answer 5

Number of action potentials.

Question 6

Define absolute refractory period?

Answer 6

No further action potentials can be elicited.

Question 7

Define relative refractory period?

Answer 7

Larger stimulus needed to reach threshold to cause AP.

Question 8

Saltatory conduction

Answer 8

AP jumps from node to node.

Question 9

Voltage clamp

Answer 9

Controls the membrane potential, measuring changes in current.

Developed by Hodgkin and Huxley, studied giant squid axon.

Question 10

How are xenopus oocytes used for neuronal research?

Answer 10

Injected with mRNA that can express functional ion channels, so they can be studied in isolation.

Families with gene mutation for K+ channel have history of epilepsy.

Question 11

What does the DAPI staining technique show?

Answer 11

DNA in neurones

Question 12

What does the Nissl staining technique show?

Answer 12

Neurones and glia. Stains RER.

Question 13

What does the Golgi staining technique show?

Answer 13

Neurones (soma and neurites)

Question 14

What does the Nauta silver staining technique show?

Answer 14

Degenerating axons

Question 15

Define axoplasmic transport, anterograde transport and retrograde transport?

Answer 15

Axoplasmpic transport: Movement of material down axon (in microtubules)

Anterograde: soma -> axon terminals

Retrograde transport: axon terminals -> soma