The establishment of a resting membrane potential and its dependence on ion gradients and ion permeability are properties of almost all cells.Whereas a nonexcitable cell that has beentemporarily and slightly depolarized will simply return toits original resting membrane potential, an electricallyexcitable cell that is depolarized to the same degree willrespond with an action potential.The unique feature of electrically excitable cells their response to membranedepolarization.