Ca2+ ions regulate many cellular processes such as secretion, proliferation, and apoptosis and they are also cofactors of many proteins.1,2 In neurons, Ca2+ entry through voltage-dependent Ca2+ (Cav) channels triggers neurotransmitter release. Fast synaptic transmission in the mammalian central nervous system (CNS) is mediated by several high voltage-dependent Ca2+ channels.Five types of Ca2+ channels are expressed in the CNS: the L-type (Cav1), N-type (Cav2.2), P/Q-type (Cav2.1), R-type (Cav2.3), and the T-type (Cav3).4 Each Cav channel is a multimeric protein composed of a pore forming α1 subunit and the auxiliary β (Cavβ), α2δ and γ subunits. There are four known Cavβ subunits, in addition to four α2δ subunits and eight γ subunits.