Figure 7. Effects of perinexal width on ephaptic coupling, for G _gap = 0 nS.

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 potentialin 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).