Voltage-dependent Ca2+ channels (Cav channels) are pivotal players in many physiological roles such as secretion, contraction, migration and excitation.The voltage dependent Ca2+ channels are composed of several subunits; α1, β, α2δ and γ. Cav channels were originally divided into six physiological types: L, N , P, Q, R, and T type.The Cav2.3 (formerly named α1E) protein, forms the R type channels. R-type channels are highly sensitive to both SNX-482 (#RTS-500) and NiCl2. Cav2.3 channels were shown to mediate fast excitatory transmission in several synapses including the hippocampus.Cav2.3 channels can be modulated by the muscarinic G-protein coupled receptors. nIn HEK-293 cells, expressing Cav2.3 channels, the R-type channel was shown to be both facilitated and inhibited by m1 and m2 muscarinic receptors. However, inhibition was much weaker than facilitation for the m1 receptor, while for m2 receptors, inhibition was much more pronounced than activation.