Time-course of reinhibition following relief of inhibition. (A) Voltage protocol for examining the time course of reinhibition. Relief of inhibition is produced by a 200-ms step to +100 mV and channel availability is assayed by a series of test pulses to +10 mV delivered at various times after the long prepulse. The test pulses are short (3 ms) to minimize entry into slow inactivation or relief of inhibition during the test pulse. (B) Time-course of reinhibition in 300 nM A-887826. Peak current during each test pulse is normalized to maximal current availability in control, determined by the test pulse to +10 mV preceding the 200-ms prepulse in control. Data points show mean ± SEM (n = 7) and are fitted with a single exponential function (smooth line). (C) Same for 1 nM VX-548 (n = 7). (D) Same for 300 nM LTGO-33 (n = 10).