Cav2.1 is a calcium channel of the P/Q type that is central to many brain processes, including learning and memory. Cav2.1 is not a classic cannabinoid receptor but its activity is modulated by cannabinoids. Since cannabinoids have a physiological effect on Cav2.1 it is effectively a cannabinoid receptor.
Brain (widespread) Brain (cerebral cortex: neurons, oligodendrocyte precursor cells, newly formed oligodendrocytes, microglia, endothelial cells)
Pertwee, R.G., Howlett, A.C., Abood, M.E., Alexander, S.P.H., Di Marzo, V., Elphick, M.R., Greasley, P.J., Hansen, H.S., Kunos, G., Mackie, K., et al. (2010). International Union of Basic and Clinical Pharmacology. LXXIX. cannabinoid receptors and their ligands: beyond CB₁ and CB₂. Pharmacol. Rev. 62, 588–631.