T-type Ca²⁺ channels play an important role in many cellular processes such as hormone secretion, neurotransmitter release and cell differentiation. T-type channels are also known to participate in the pacemaker activities of the heart and neurons including thalamic neurons.¹

Three genes encoding T-type Ca²⁺ channels have been cloned and designated as Ca_V3.2 (CACNA1H), Ca_V3.1 (CACNA1G) and Ca_V3.3 (CACNA1I).^1-3  

The Ca_V3.2 channel is widely expressed in various tissues such as the brain, heart, liver and testis.

Involvement of Ca_V3.2 Ca²⁺ channels in several pathologies has been described. Overexpression of the Ca_V3.2 channel was described in prostate cancer cells that are associated with more aggressiveness, invasiveness and poor prognosis.⁴ Several point mutations discovered in the Ca_V3.2 channel that affect gating of the channel were found to be associated with Childhood Absence Epilepsy.⁵ One year old mice, deficient in Ca_V3.2 channel, exhibited severe cardiac pathology, fibrosis, necrosis, lymphocyte infiltration and abnormal coronary function compared to wild-type mice.⁶ 

Recently, it has been demonstrated that T-type channels are expressed in DRG neurons and that small and medium-diameter primary afferent neurons in the dorsal horn expresses almost exclusively the Ca_V3.2 Ca²⁺channels. This might indicate a possible role for Ca_V3.2 in nociception.⁷