Figure 5

ATX, a reagent of preventing VGSC inactivation, reduces spike thresholds and shortens refractory periods at the axon. Spike thresholds and refractory periods are measured dynamically by changing the patterns of input signals at the axon. A) shows the effect of ATX on axonal spike thresholds (green traces). B) shows threshold stimuli vs. depolarization time at the axon. ATX reduces axonal spike thresholds significantly (green symbols; asterisks, p < 0.05, n = 14; paired t-test). C) shows the effects of ATX on the refractory periods of axonal spikes (green trace). D) illustrates spike refractory periods vs. depolarization time at the axon. ATX shortens the refractory periods of axonal spikes induced mainly by long-time pulses (green symbols, n = 13; asterisks, p < 0.05).