The aciton potential (cells of NS)

Question 1

What is the action potential?

Answer 1

• Transient change in membrane potential capable of nondecremental self propagation along an axon of the neurone
• Allows neurones to communicate w other neurones

Question 2

What are the properties of an action potential?

Answer 2

• Robust
• Rapid
• Orthodromic
• All or nothing
• Frequency encoded

Question 3

What can you use to measure an AP?

Answer 3

Extracellular electrophysiology

Erlanger & Gasser, 1920s used this

Question 4

What is compound action potential (CAP)?

Answer 4

Population response, sum of APs from all the axons simultaneously contributing to the signal

Question 5

What did Hodgkin and Huxley (1939) use to study APs?

Answer 5

Intracellular electrophysiology

(Inserted an electrode into the axoplasm)

Question 6

What are the 6 parts elements of an AP happening?

Answer 6

• Resting
• Depolarisation
• (Overshoot)
• Peak
• Repolarisation
• After hyperpolarisation

Question 7

What is overshoot?

Answer 7

How far the membrane potential goes past the threshold