T-type voltage-dependent calcium channel (T-type VGCC) (T-type VGCC)

T-type voltage-dependent calcium channels, also known as low-voltage-activated (LVA) calcium channels, are critical regulators of cellular excitability and rhythmic firing patterns in the central nervous system and cardiovascular system (Perez-Reyes, 2003, Physiological Reviews). Unlike high-voltage-activated channels, T-type channels (comprising Cav3.1, Cav3.2, and Cav3.3 subtypes) open in response to small depolarizations near the resting membrane potential, allowing them to influence pacemaker activity and signal integration (Iftinca & Zamponi, 2009, Trends in Pharmacological Sciences). They are primarily involved in the pathogenesis of absence epilepsy, where they contribute to the characteristic 3 Hz spike-and-wave discharges, as well as in the transmission of neuropathic pain signals in the spinal cord (Cheong & Shin, 2013, Pflügers Archiv). Therapeutic strategies focus on small-molecule inhibitors, such as ethosuximide and zonisamide, which block the channel pore to dampen neuronal hyperexcitability (Zamponi et al., 2015, Pharmacological Reviews). Beyond neurology, these channels are investigated for their roles in cardiac conduction, hormone secretion, and even cancer cell proliferation, making them versatile targets for drug development (Cribbs, 2006, Circulation Research).

Other names

Low-voltage-activated calcium channelLVA calcium channelCav3 channelCACNA1GCACNA1HCACNA1I

Inhibition of the channel pore to reduce calcium influx during low-voltage depolarization, thereby dampening rhythmic firing and hyperexcitability.