Depolarization is the process or the act by which polarity is eliminated. It may also refer to the result of such action so that the result is an unpolarized condition. In physiology, depolarization occurs in a living cell (e.g. nerve cells). Depolarization in a nerve cell occurs when the cell undergoes an electrical change. Most cells are negatively charged relative to their surroundings. This negative internal charge of the cell shifts to a positive through the process of depolarization. Depolarization though occurs for only a brief period of time.
Depolarization is essential because it allows the transmission of electrical signals (impulses) within the cell, and in certain instances, from one cell to another. Depolarization therefore is one mechanism employed by cell to carry on certain physiological functions and also to communicate with another cell.