Fig. 5.

A significant proportion of the persistent Na⁺ current is attributable to Na⁺ channels containing the Nav1.6 α-subunit.A,B, Comparison of the basic characteristics of the steady-state activation and inactivation kinetics of the rapidly inactivating Na⁺ currents in the wild-type (A) and null Nav1.6 allele mice (B) indicates that they are similar.C, The window current (inset) resulting from the rapidly inactivating Na⁺ currents is not modified in null allele mice (solid lines) as compared with controls (dottedlines).D, The persistent Na⁺ current is smaller in the null allele mice as compared with controls. The current traces represent the average of four cells in each case, and thesolid lines are the best corresponding polynomial fit. E, Box plot summary of the density of persistent Na⁺ current in wild-type (n = 7) and null allele mice (n= 7). F, Box plot summary of the density of the rapidly inactivating Na⁺ current indicating that there is no decrease in the null allele mice (n = 8) as compared with the control (n = 12).