Cav3.1 is a calcium channel of the T-type that is involved in many processes in the brain and other tissues. Contrary to other calcium channels Cav3.1 is activated by relatively low/negative voltages. Cav3.1 is not a classic cannabinoid receptor but its activity is modulated by cannabinoids. Since cannabinoids have a physiological effect on Cav3.1 it is effectively a cannabinoid receptor.