Mutations in the β3 intracellular domain destabilize Nav1.3 inactivation. A, shown is a summary of the β3 intracellular domain mutants used in the electrophysiological analysis. Shown are mean channel availability plots (B) and difference curves for Nav1.3 cells/no β3, Nav1.3 cells/β3-WT, Nav1.3 cells/β3-AP, and Nav1.3 cells/β3-ΔSE using data from all cells (C). Means (± S.E.) were generated from the following sample numbers: Nav1.3/no β3, n = 26; Nav1.3/β3-WT, n = 15; Nav1.3/β3-AP, n = 13; Nav1.3/β3-ΔSE, n = 12.