Fig. 10

Multiple inward currents. A Voltage clamp recording with two depolarizing currents, a conventional I_Na (inward 1) and a relatively small and slow delayed inward current (inward 2). B The I–V relations for the two currents and the scaled up inward 2 current; inward 2 current was isolated by (1) removing the delayed current-containing part of the trace, (2) fitting the remaining trace between 5 and 30 ms with a polynomial equation, and (3) subtracting the fitting curve from the original trace. C A current-clamp recording from the same cell with two types of voltage spikes that correspond to the currents in A. D–F A recording from another cell, D with three waves of inward currents, E the corresponding I–V relations, and F the current-clamp recording. G Example of four inward currents from a different cell. H An example of recordings where the delayed inward current (inward 2, left) disappeared spontaneously after 5 min of recordings (right)