Tetrodotoxin-sensitive voltage-gated sodium channels (TTX-S Nav channels) (TTX-S Nav channels)

Tetrodotoxin-sensitive voltage-gated sodium channels (TTX-S Nav) are essential transmembrane proteins that mediate the rapid influx of sodium ions required for the initiation and propagation of action potentials in neurons, including those within the dorsal root ganglion (DRG) (Catterall, 2000, Neuron). In the DRG, this functional group primarily comprises the Nav1.1, Nav1.2, Nav1.3, Nav1.6, and Nav1.7 subtypes, which are distinguished by their high affinity for the pufferfish toxin tetrodotoxin (Rush et al., 2007, Journal of Physiology). These channels are pivotal in sensory processing, particularly in the transmission of nociceptive signals from peripheral tissues to the spinal cord (Dib-Hajj et al., 2013, Nature Reviews Neuroscience). Abnormal expression or gain-of-function mutations in TTX-S channels, especially Nav1.7, are directly linked to severe pain disorders such as erythromelalgia and paroxysmal extreme pain disorder (Waxman, 2006, Nature). Pharmacologically, these channels are the primary targets for local anesthetics and several classes of anticonvulsants, which act by blocking the aqueous pore or stabilizing non-conducting states (Goldin, 2001, Annual Review of Physiology). Current therapeutic research focuses on developing subtype-selective inhibitors to treat chronic pain while avoiding the systemic side effects associated with non-selective sodium channel blockade in the heart and central nervous system (Wood et al., 2004, Journal of Neurobiology).

Other names

TTX-sensitive sodium channelsTTX-S VGSCsFast-inactivating sodium channelsTTX-S Nav channels

Inhibition of sodium ion influx through the channel pore, often by binding to the local anesthetic receptor site or stabilizing the inactivated state of the channel.