Current recorded from a cut-open giant axon under voltage clamp.

Squid giant axons were cut open and the resulting membrane sheet was positioned in a chamber separating two compartments. Under voltage clamp, normal sodium, potassium, and gating currents could be recorded for several hours. This preparation allows direct access to the internal side of the axonal membrane and should prove useful for recording of ionic currents, gating currents, and channel-induced current fluctuations in the same membrane sheet.