Action potential

An action potential (often called a "spike") is a brief change in voltage that travels along a cell membrane. An action potential is typified by the depolarization of a membrane which has a negative resting potential.

Action potentials generated in neurons travel along axons to their nerve endings, depolarisation of which results in the release of neurotransmitters, which cross the cleft (synapses) between the nerve endings and other neurons. Action potentials are thus a major element involved in the transmission of information in the brain and peripheral nervous system.