The problem of nonstationary ion fluxes in excitable membranes.

Time-dependent electrodiffusion through a membrane is analysed within a simple model treating the boundary-layers in a consistent manner. It is shown that time-independent reversal potentials for the ion fluxes exist only under steady-state conditions. We argue that this result holds very generally. Therefore nonstationary effect like ion storage and depletion inside the membrane should not contribute to the phenomena of excitability.