Localization of Na⁺ channel clusters in narrowed perinexi of gap junctions enhances cardiac impulse transmission via ephaptic coupling: a model study.

ABSTRACT: It has been proposed that when gap junctional coupling is reduced in cardiac tissue, action potential propagation can be supported via ephaptic coupling, a mechanism mediated by negative electric potentials occurring in narrow intercellular clefts of intercalated discs (IDs). Recent studies showed that sodium (Na⁺ ) channels form clusters near gap junction plaques in nanodomains called perinexi, where the ID cleft is even narrower. To examine the electrophysiological relevance of Na⁺ channel clusters being located in perinexi, we developed a 3D finite element model of two longitudinally abutting cardiomyocytes, with a central Na⁺ channel cluster on the ID membranes. When this cluster was located in the perinexus of a closely positioned gap junction plaque,

SUBMITTER: Ivanovic E 

PROVIDER: S-EPMC9293295 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature