Figure 4.
Q558H modifies inactivation of Cav1. 3 during sustained depolarizations. A, representative traces for currents evoked by a 3-s test pulse from −80 mV to +10 mV in cells transfected with WT or mutant channels. Inset, normalized traces of the displayed currents with expanded time scale showing faster initial inactivation of Q558H compared with WT. B and C, comparison of kinetics of inactivation of WT (n = 9 cells) and Q558H channels (n = 14 cells). Time constants (τfast, τslow) (B) and fractional amplitudes (Ffast and Fslow) (C) were obtained from double exponential fits of current traces obtained as in (A). Error bars represent S.E. p values were determined by t test. Results are from five independent experiments.