Fig. 1.

Schematic diagram of the endocannabinoid system. Endocannabinoid AEA and 2-AG are released after postsynaptic synthesis to retroactively bind to endocannabinoid receptors (CB1 and CB2) at the presynaptic site. Exogenous cannabinoids such as phytocannabinoids (CBD and Δ9-THC) and synthetic cannabinoids (HU-210 and JWH-018) can also be added to the synapse to activate endocannabinoid receptors. FAAH and MAGL exist simultaneously in presynaptic and postsynaptic regions and hydrolyze endogenous cannabinoids. AEA anandamide, 2-AG 2-arachidonoyl-glycerol, FAAH fatty acid amide hydrolase, MAGL monoacylglycerol lipase, CBD cannabidiol, Δ9-THC Δ9-tetrahydrocannabinol