FIGURE 4.

Recovery from VDI is described by two kinetically distinct components. Pulse protocol (A) and gating currents after 1 s (B, left) and 20 s (C, right) conditioning pulses and different recovery times (Tip, listed next to gating currents) at −60 mV. Qn diminishes as recovery time increases. (D) Average Qn (normalized to Qn after 50 ms of recovery) versus recovery time at −60 mV after T_C = 1 s (n = 13) or 20 s (n = 8). The slow component of recovery is increased upon a longer conditioning pulse. These results suggest that VDI that occurs slowly recovers slowly. (E) The semilog plot is shown. Best fit parameters for recovery of Qn after either conditioning pulse: τ_fast = 0.17 s and τ_slow = 3.7 s. Relative amplitudes: for T_C = 1 s, a_fast/a_T = 0.74, a_slow/a_T = 0.22; and for T_C = 20 s, a_fast/a_T = 0.55, a_slow/a_T = 0.40 (a_T = a_fast + a_slow).