Electrophysiological recordings

Question 1

Describe the current clamp technique.

Answer 1

Clamping the current: we decide which current we want to inject, and record the resulting changes in the Vm

Question 2

What can you measure with current clamp?

Answer 2

EPSPs, IPSPs and APs

Question 3

Describe the voltage clamp technique.

Answer 3

Clamping the voltage: we decide the Vm, and the amplifier tells us how much current is needed for this

Question 4

What can you measure with voltage clamp?

Answer 4

EPSPs and IPSPs

Question 5

Describe the patch clamp technique.

Answer 5

Microscopic current flow through single channels. Can be both current and voltage clamped

Question 6

What are some variantions of the patch clamp technique?

Answer 6

Whole cell
Inside-out: the cytoplasmic domain of the receptor is accessible
Outside-out: the extracellular domain of the receptor is accessible

Question 7

How can we indirectly measure the concequence of an AP in vivo?

Answer 7

Ca2+ imaging

Question 8

What are some methods to measure APs in humans?

Answer 8

EMG: myo = muscles
ENG: peripheral nerves
EEG: encephalon = brain