Figure 2.

Three different I_K recordings from a squid giant axon preparation (Clay & Shlesinger 1983) taken from a family of recordings in which the holding potential was −75 mV, and the step potential (V_step) ranged from −55 to +35 mV in 10 mV increments with a 3 s rest interval between each step. The sodium ion current, I_Na, was blocked by tetrodotoxin (1 μM; Sigma Chemical Co., St Louis, MO). The initial times of each step are offset from one another. The currents at the end of each step, I_o, are indicated by the respective horizontal bars. T=6.8°C.