Patch clamp electrophysiology

Alexander van Aken

• NEUROPHYSIOLOGY OF THE ACTION POTENTIAL

• ION CHANNELS

• PATCH CLAMP TECHNIQUE

Neuronal communication

electrical and chemical

The action potential

Changes in membrane potential are caused by ion channel activity

ION CHANNELS

GATED

SELECTIVE FOR IONS

Voltage gated sodium and potassium channelsgenerate the action potential

THE COMBINED ACTIVITY OF ION CHANNELS GENERATES THE ACTION POTENTIAL

Hodgkin and Huxley experiments 1950’s

• How do we investigate the characteristics of individual ion channels?

• How do we investigate the voltage dependence of sodium and potassium channels during the action potential?

Patch clamp electrophysiology

4 pA

10 ms

•How do we investigate the characteristics of individual ion channels?

Voltage clamping the membrane potential

Whole cell potassium currents at different membrane potentials

• Measuring currents at clamped potentials to determine IV-relationships of either individual ion channels or ion channel populations.

• The action potential is a temporary change in membrane potential. This change is caused by the activity of ion channels but..

• Voltage gated ion channel activity is regulated by the membrane potential.

• The interaction between the microscopic level (ion channels) and macroscopic level (membrane potential) works in two directions, bottom up and top down.