Sodium channels in the Cx43 gap junction perinexus may constitute a cardiac ephapse: an experimental and modeling study.

ABSTRACT: It has long been held that electrical excitation spreads from cell-to-cell in the heart via low resistance gap junctions (GJ). However, it has also been proposed that myocytes could interact by non-GJ-mediated "ephaptic" mechanisms, facilitating propagation of action potentials in tandem with direct GJ-mediated coupling. We sought evidence that such mechanisms contribute to cardiac conduction. Using super-resolution microscopy, we demonstrate that Nav1.5 is localized within 200 nm of the GJ plaque (a region termed the perinexus). Electron microscopy revealed close apposition of adjacent cell membranes within perinexi suggesting that perinexal sodium channels could function as an ephapse, enabling ephaptic cell-to-cell transfer of electrical excitation. Acute interstitial edema (AIE) increa

SUBMITTER: Veeraraghavan R 

PROVIDER: S-EPMC4500747 | biostudies-literature | 2015 Oct

REPOSITORIES: biostudies-literature