Voltage-gated sodium channels are a type ofvoltage-gated channelspecific to Sodium (Na⁺). Due to theirstructure, when the β -subunits detect a change in voltage, the channel opens the channel gate to facilitate the flow of Sodium (Na⁺) ions through the pore.

This channel also includes an inactivation "lid", a cytoplasmic loop that can bind into and block the channel, effectively as if closing it, thus preventing the channel to be open for too long in case of continuous stimulation with multipleaction potentials. This mechanism prevents the jamming of signals with a minimal refractory time period between each action potential, otherwise, the sodium ion channel would stay constantly opened and repolarization would not occur.