Figure 1.

Patch-clamp electrophysiology. (a) Formation of the gigaΩ seal and the subsequent cell-attached and whole-cell configurations. (b) Enhanced view of the membrane–pipette arrangements in the cellattached and whole-cell confi gurations. In a cell-attached patch, unitary currents are produced by ion fl ux through single channels. Three different channel types are shown. In the whole-cell mode, the macroscopic current recorded is the summation of all the currents generated by similar channels throughout the cell. (c) Measured parameters. Single-channel recordings can provide information relating to the amplitude the unitary currents, the open probability of the channels and the amount of time the channel(s) spend in open (open duration) or closed (closed duration) confi gurations. Macroscopic currents are characterized by the current amplitude, activation, inactivation and deactivation during a pulse protocol