Stimulation-rate dependence of Y1795C channel sustained current (Isus): agreement between simulated and experimental data. (a) The panels compare experimental (left) and simulated (right) records of Y1795C channel sustained current (Isus) during trains (20 pulses) of repetitive voltage pulses applied after a pulse-free period. Shown is the superposition of current in response to the first and 20th pulses (–10 mV, 500 milliseconds). The experimental records are TTX-sensitive currents (see Methods). The interpulse interval was 20 milliseconds. (b) Pulse-dependent changes in Isus during rapid stimulation. Isus during successive pulses (Isusn) was normalized to Isus recorded (left) or computed (right) during the first pulse (Isus1) of the pulse train and plotted versus pulse number. The interpulse interval was 20 milliseconds. (c) Pulse-dependent changes in Isus in response to slow stimulation rate. Isus was measured, computed, and plotted as in b, but in this case the interpulse interval was 1 second. CL, cycle length.