action potential

An action potential is a brief change in a cell's membrane potential from negative inside to positive inside. Action potentials can rapidly move along the surface membrane of a muscle cell or nerve cell.

Online Guyton medical physiology textbook: nerve action potential, heart action potentials

Additional information. The ionic basis of action potentials in Neuroscience. 2nd edition. Purves D, Augustine GJ, Fitzpatrick D, et al., editors.

Figure (above). This neuronal action potential has a "rising" or "depolarization" phase during which sodium ions (Na+) enter the cell and a "repolarization" phase during which potassium ions leave the cell. In this neuron, the resting membrane potential is about -60 mV, inside negative.

See: current.