Voltage-clamp experiment of cultured neuron.Top, Protocol of intracellular voltage with a holding voltage of −50 mV, a prepulse of −110 mV, and an activation pulse of +20 mV. Center, Whole-cell current with constant K-type signal and transient A-type component. Bottom, Transistor voltage with K-type signal and without A-type response. Shown is an average of 30 records. The interval between the records was 5 sec.