Figure 4. A family of currents acquired using large depolarizations under voltage-clamp control.

There are a few unusual features of this original recording. Both the traces and voltages have the opposite sign to the current convention, inward currents are shown plotted upwards and depolarizations are given relative to the holding potential as that of the outside with respect to the inside. The –91 mV step represents a depolarization of the inside of the nerve fibre to ∼+15 mV. Modified from Hodgkin et al. (1952).