Figure 3. Voltage- and time-dependence of I_BK and I_Kv.

Family of membrane currents activated by IV1 protocol. A, control (5 mm glucose + 200 μm tolbutamide). B, in 1 μm paxilline. C, I_Kv recorded in the presence of Cd²⁺ and paxilline. The continuous lines are single exponential fits to the rising phase of the current. D, paxilline-sensitive I_BK, obtained by subtracting the currents in B from A. The continuous lines are monoexponential fits of I_BK decay. E, Cd²⁺+ paxilline-sensitive current, obtained by subtracting traces in C from A. F, I_BK activation. The early phase of I_BK, shown in D, is plotted on an expanded time scale. The continuous lines are double exponential fits to I_BK rising phase. G, early inward I_Cav current. The traces were obtained by plotting the early stages of the traces in E on an expanded time scale. The leftmost calibration bars refer to A, B and C; the middle bars refer to D and E, and the rightmost bars refer to F and G.