Voltage-gated sodium channel

Voltage-gated sodium channels are transmembrane protein complexes primarily localized to the plasma membrane of excitable cells, such as neurons and muscle cells. These channels are composed of a pore-forming alpha subunit and one or more auxiliary beta subunits. Their essential physiological function is to open rapidly in response to membrane depolarization, allowing a swift influx of sodium ions that initiates and propagates action potentials, which are fundamental for nerve impulse transmission and muscle contraction.