ClC-1 current deactivation is unaffected by formamide detubulation. Average voltage dependence of the relative contribution of slow (A), fast (B), and steady-state (C) components to ClC-1 deactivation in separate populations of naive (filled circles) and detubulated (open squares) FDB fibers from 15–16-d-old mice. (D) Voltage dependence of fast (squares) and slow (circles) time constants of ClC-1 deactivation in naive (filled symbol) and detubulated (open symbol) FDB fibers from 15–16-d-old mice. Data are mean ± SEM from 20 and 18 control and detubulated fibers, respectively.