Fig. 3.
Kinetics of fast inactivation of wild-type rNav1.1 and GEFS+ 2 mutant channels. Sodium currents were recorded from oocytes expressing wild-type rNav1.1 (white symbols andbars), DII (gray symbols andbars), and DIV (black symbols andbars) channels, as described in the legend to Figure 1. Current traces were fit with either a single or a double exponential equation, as described in Materials and Methods, and time constants for the fast (τfast, circles) and slow (τslow, triangles) components of fast inactivation are plotted on a logarithmic scale in thetoppanels for α subunits alone (A) and α + β1 subunits (B). The bottom panels indicate the fraction of current inactivating with τfast. In all cases the sum of the components is one. The values shown are averages; the error bars indicate SD. Sample sizes were rNav1.1 α (4), DII α (5), DIV α (4), rNav1.1 α + β1 (4), DII α + β1 (5), DIV α + β1 (7).