Sodium Channel

Sodium channels are integral membrane proteins that form ion channels, conducting sodium ions (Na⁺) through a cell's plasma membrane. They are classified according to the trigger that opens the channel for such ions, i.e. either a voltage-change (Voltage-gated, voltage-sensitive, or voltage-dependent sodium channel also called VGSCs or Nav channel) or a binding of a substance (a ligand) to the channel (ligand-gated sodium channels). In excitable cells such as neurons, myocytes, and certain types of glia, sodium channels are responsible for the rising phase of action potentials. Voltage-gated Na+ channels can exist in any of three distinct states: deactivated (closed), activated (open), or inactivated (closed). Ligand-gated sodium channels are activated by binding of a ligand instead of a change in membrane potential.