action potential

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A momentary change in electrical potential on the surface of a cell, especially of a nerve or muscle cell, that occurs when it is stimulated, resulting in the transmission of an electrical impulse.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A short term change in the electrical potential that travels along a cell such as a nerve or muscle fiber.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the local voltage change across the cell wall as a nerve impulse is transmitted