Fig. 2

Voltage-gated Na current. Upward deflection of bottom trace indicates the timing and duration of the voltage pulse. a Current waveform by depolarization to −10 mV (V _h = −100 mV). Black trace shows the current in the perfusion solution. Red trace shows the current in the choline solution. Averaged waves of the current generated by the 30 times depolarization pulse. b Capacitive and leak current subtraction. The current waveforms in a were subtracted to show the voltage-gated Na current. c The current measured with P/4 subtraction. Membrane current evoked by depolarization to −10 mV (V _h = −100 mV). The P/4 subtraction function was supplied with pClamp. Different cell from a and b. A downward large transient shows a capacitive current. Corrected capacitive current was negative, because the capacitive current in the original trace was over-saturating the range of the A/D converter, whereas the four smaller currents used for subtraction were within the range