English: Top: schematic and mesh of the ID (inset showing its high density region), with the central Na+ channel cluster (red) located inside the perinexus (grey) of a closely apposed gap junction plaque (green). Simulation results for G gap = 0 nS and bulk cleft widths w cleft of 30 nm (left column), 50 nm (middle column) and 100 nm (right column). Perinexus width w peri was varied from 5 nm up to the bulk cleft width (see colour key upper right). First row: intracellular potentialAn external file that holds a picture, illustration, etc. Object name is TJP-599-4779-e028.jpgin cell 1 (continuous lines) and cell 2 (dashed lines); second and third rows: Na+ current in the ID and the bulk membrane of cell 1 (continuous lines) and cell 2 (dashed lines), respectively; fourth row: minimal extracellular potential in the cleft (dash‐dotted lines) as a function of time. The labels of selected traces indicate w peri. The rectangles denote the portions of the plots that were magnified (insets).