Figure 6.

Correction of activation curves for Ca²⁺ induced acceleration of deactivation. The three-pulse protocol at the top of A was used. The membrane potential was held at −80 mV, and then stepped to a test potential of +50 to −70 mV for 3 s. A step to −100 mV for 12.5 ms allowed recovery from inactivation. The final step to +30 mV was 35 ms in duration. A representative family of current recordings in A is shown on a split time scale for clarity. The time scale bar applies only to the portion of the recording after the break. (B) Current measured at the immediate beginning of the third pulse plotted as a function of the test pulse potential in 1.8 (•) and 10 (○) mM Ca²⁺ is shown. (C) Current measurements from B after correction for deactivation that occurred during the 12.5-ms recovery step to −100 mV are shown. The correction was made as in Fig. 5.