Voltage-dependent N-type calcium channel (Cav2.2) (Cav2.2)

The voltage-dependent N-type calcium channel, specifically the Cav2.2 subtype encoded by the CACNA1B gene, is a critical mediator of neurotransmitter release at presynaptic terminals within the central and peripheral nervous systems (UniProt, Q00975). Upon membrane depolarization, these channels open to allow an influx of calcium ions, which triggers the exocytosis of synaptic vesicles containing neurotransmitters such as glutamate, calcitonin gene-related peptide (CGRP), and substance P (PubMed, 25333798). Cav2.2 is particularly prominent in the dorsal horn of the spinal cord, where it plays a fundamental role in the processing and transmission of nociceptive (pain) signals (StatPearls, NBK534248). Due to its central role in pain signaling, it is a validated therapeutic target for chronic and intractable pain conditions. Ziconotide, a synthetic peptide derived from cone snail venom, is a potent and selective Cav2.2 blocker used clinically for severe chronic pain, though its use is limited by the need for intrathecal administration and potential for central nervous system side effects (IUPHAR/BPS, Cav2.2). Beyond pain, Cav2.2 is involved in autonomic regulation and has been investigated in the context of other neurological disorders like epilepsy and certain types of hypertension (PubMed, 30103312).

Other names

CACNA1BN-type voltage-gated calcium channelCalcium channel voltage-dependent N-type alpha 1B subunitBIIICaV2.2

The primary mechanism of action involves the selective blockade of the Cav2.2 channel pore, which inhibits the influx of calcium ions into presynaptic terminals and subsequently reduces the release of excitatory neurotransmitters like glutamate and substance P (StatPearls, NBK534248). Additionally, some drugs like gabapentinoids interact with the auxiliary alpha2delta-1 subunit to modulate channel trafficking and reduce the density of functional N-type channels at the synapse (PubMed, 25333798).