The endocannabinoid system is a signaling network in the brain and periphery that plays a role in maintaining the balance of many of our physiological functions, including sleep, appetite, pain, memory, and mood. The system is also the target of the psychoactive substance in the cannabis plant, tetrahydrocannabinol (THC), which produces its effects through activation of two cannabinoid receptors, CB1 and CB2. In the brain, CB1 activation reduces excessive neurotransmission, while CB2 activation reduces inflammatory signaling. The naturally occurring activators of the cannabinoid receptors are the endogenous cannabinoids, or endocannabinoids, anandamide and 2-arachidonoylglycerol (2-AG).