Voltage-gated neuronal sodium channel (VGSC) (VGSC)

Voltage-gated neuronal sodium channels (VGSCs) are transmembrane proteins that are essential for the initiation and propagation of action potentials in the central and peripheral nervous systems [1]. These channels consist of a large, pore-forming alpha subunit, which determines the primary functional properties, and auxiliary beta subunits that regulate channel kinetics and membrane localization [2]. In humans, nine distinct alpha subunit isoforms (Nav1.1–Nav1.9) have been identified, with Nav1.1, Nav1.2, Nav1.3, and Nav1.6 being the primary isoforms in the central nervous system, while Nav1.7, Nav1.8, and Nav1.9 are predominantly found in the peripheral nervous system [3]. Mutations in the genes encoding these channels, such as SCN1A or SCN9A, are linked to various channelopathies including severe myoclonic epilepsy of infancy (Dravet syndrome) and inherited pain disorders like erythromelalgia [1, 4]. Pharmacologically, these channels are the targets of a wide range of drugs, including local anesthetics, anti-epileptic drugs, and certain anti-arrhythmics, which typically act by blocking the aqueous pore or stabilizing the inactivated state of the channel [2, 3]. Modern drug discovery efforts are focused on developing subtype-selective inhibitors, particularly for Nav1.7 and Nav1.8, to treat chronic pain with improved safety profiles compared to non-selective blockers [1].

Other names

Voltage-dependent sodium channelNav channelSodium channel protein type subunit alphaVoltage-gated sodium channel

Drugs targeting these channels typically act as state-dependent blockers that bind with higher affinity to the inactivated or open states rather than the resting state, thereby selectively inhibiting high-frequency firing in pathological conditions [1, 3].