L-type voltage-gated Ca²⁺ currents in WT and V876E fibers. (A) Recordings of L-type currents (top) in a WT and in a V876E fiber in response to depolarizing pulses of 1 s duration to the indicated voltages (bottom). (B) Relationships between the mean peak values of L-type Ca²⁺ currents and membrane voltage in the two fiber types. (C) Mean of the fitting parameters of current-voltage relationships obtained in each WT and V876E fiber. E1/2, half-activation voltage; Erev, apparent reversal potential; Gmax, maximum conductance; k, steepness factor. Data are given as means ± SEM.