Persistent Na+ currents in cells transfected
with the Q1491H mutant channel
Persistent non-inactivating Na+ currents were recorded
using a 400-ms depolarization pulse from –140 mV to –30 mV (see
protocol inset) and were normalized to the peak. The current was
inhibited using 25 𝛍M tetrodotoxin (TTX). Only the Q1491H mutant channel
displayed a significant decrease in current (2.66 ± 0.29 to 1.25 ±
0.22), indicating the presence of a persistent current (Fig.
6) . TTX had no effect on the G1481V mutant and WT currents, which is
indicative of a non-specific leak.