What is an action potential?

An action potential is defined as a temporary reversal of the electrical potential across a neuron's membrane. This process is essential for the transmission of electrical signals along neurons and is a key mechanism in how nerve impulses are generated and propagated.

When a neuron is stimulated sufficiently, ion channels in the membrane open, allowing sodium ions to rush into the cell. This influx of positive charge causes the inside of the cell to become more positively charged relative to the outside, leading to the temporary reversal of the membrane potential. Following this depolarization, potassium channels open, allowing potassium to exit the cell, restoring the resting potential.

This process is crucial for the functioning of the nervous system, as it allows for rapid communication between neurons. Understanding that action potentials are temporary helps clarify that they are not permanent changes in the neuron’s electrical state. This dynamic nature is fundamental in enabling neurons to return to their resting state and be ready to fire again.