Negative shifts in SSA and positive shifts in SSI enhance conduction. Contour maps of the CV are shown as functions of $Vactshift$ and $Vinactshift$⁠, for different values of cleft widths (w) and (A–C) gap junction conductance g_gap, with 1 cm/s spacing. Parameters: mix/homogeneous-polarized distribution, f_Na = 0.7. The o and x denote the baseline and nominal shifted Na⁺ channel values, respectively.