SELF-GATING OF ION CHANNELS IN CELL-ADHESION

When a cell membrane is attached to an inert surface, ionic current ma y flow from the bath along the narrow cleft between membrane and surfa ce into the cell kept at constant potential. This current modifies the voltage across the membrane due to the voltage drop in the cleft. As a result, the conductance of voltage-gated ion channels is affected. B y positive feedback, smooth gating is transformed into switching with bistability, hysteresis, and memory as shown by cable theory. Self-gat ing in cell adhesion is triggered by minute modulations of the attachm ent or of the intracellular potential.