ABSTRACT
This chapter focuses on the electrical consequences of charge separation across membranes. It explores both how cells establish charge separation and how they use it. Beyond preserving the integrity of the cell, the membrane also serves an important function in electrical signaling. By maintaining a potential difference between the cellular interior and its exterior, the membrane provides the physical basis for this form of signaling in which the steady-state value of the membrane potential can be disrupted due to a chemical, electrical, or mechanical stimulus and this disturbance can propagate along the cell membrane. In order to generate electric potentials and currents, ions alone are not enough. It is necessary that the cell create mechanisms for separating and concentrating ions and permitting them to pass only through predefined conduits. Life is dynamic. One of the most intriguing features of action potential is observation that creation of pulse requires the stimulating voltage difference to exceed a threshold value.
