Fig. 6.

Mathematical simulation of action potentials incorporating observed effects of elimination of Kv1 versus Kv2 channel function elimination. The mathematical model derived by Lockery and Spitzer (1992) was run under control (thick dotted line) and variant I_Kv conditions for mature neurons. G_max was reduced by 33% alone (Kv1 elimination, thin dotted line) or in combination with a −5 mV shift in V_1/2 (Kv2 elimination,solid line). The horizontal dashed lineindicates the value of half-repolarization, the voltage at which the impulse duration is determined; its leftmost position is at the time to peak. A simulated action potential produced by reducingG_max by 82% (“observed”, thick dashed line) had a fourfold increase in its duration. The duration of the impulse is defined here as the time between the peak and half-repolarization and was 1.12, 1.25, and 4-fold that of control for Kv2 elimination, Kv1 elimination, and “observed”, respectively.