action potential

American  

noun

Physiology.

1. the change in electrical potential that occurs between the inside and outside of a nerve or muscle fiber when it is stimulated, serving to transmit nerve signals.

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action potential British  

noun

1. a localized change in electrical potential, from about –70 mV to +30 mV and back again, that occurs across a nerve fibre during transmission of a nerve impulse

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action potential Scientific  

/ ăk′shən /

1. A momentary change in electrical potential on the surface of a neuron or muscle cell. Nerve impulses are action potentials. They either stimulate a change in polarity in another neuron or cause a muscle cell to contract.

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action potential Cultural  

1. The rapid change in electric potential that parts of a nerve cell undergo when a nerve impulse is generated. Unlike ordinary electric current (see also current), which consists of the flow of electrons, the action potential involves the movement of sodium and potassium ions across the cell membrane.

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Etymology

Origin of action potential

First recorded in 1925–30

Example Sentences

The voltage shifts can occur within milliseconds, which aligns closely with the shape and speed of typical action potential curves for neurons.

From Science Daily • Dec. 16, 2025

The researchers inserted a bundle of fine micro wires, capable of recording the action potential of a single neuron, through the hollow inner canal of depth electrodes implanted as part of the epilepsy procedure.

From Salon • Feb. 15, 2025

It was thought that chandelier cells could exert strong control over pyramidal cells by blocking the action potential.

From Science Daily • Jan. 10, 2024

Figure 20.32 An action potential is the pulse of voltage inside a nerve cell graphed here.

From Textbooks • Aug. 12, 2015

This makes it the most easily-excited part of the neuron and the spike initiation zone for the axon: in neurological terms it has the greatest hyperpolarized action potential threshold.

From Textbooks • Jan. 1, 2015