Figure 1.

Effects of SKF83959 on the gating kinetics of the Na⁺ channel in dissociated hippocampal neurons experiments. (A) Activation curve of the voltage-dependent Na⁺ channel. The inset shows the voltage-clamping protocol; the membrane potential was clamped at −80 mV, and after a prepulse (−120 mV, 50 ms), a series of voltages, from −70 mV to −10 mV with steps of 5 mV and of 30 ms duration, were applied to the cell. Each Na⁺ current was converted to conductance. G_max: the maximum conductance. Mean±SEM (n=7). (B) Inactivation curve of voltage-dependent Na⁺ channel. The inset shows the voltage-clamping protocol; the membrane potential was clamped at −80 mV, and a series of voltages, from −80 mV to −10 mV with steps of 5 mV and of 100 ms duration, were applied to induce the inactivation of Na⁺ channels. The voltage was then clamped at −20 mV for 30 ms, and Na⁺ currents (I) were measured. I₀, the maximum current. Mean±SEM (n=5). Control: open circle. SKF83959: black circle.