Cannabinoid receptors have been identified in all of the following except
Cannabis
Cannabis preparations are obtained from the plant Cannabis sativa.
Common names for cannabis include:
- marijuana
- grass
- pot
- weed
- tea
- Mary Jane
The plant contains more than 60 cannabinoids that are unique to the plant. Delta-9-tetrahydrocannabinol is the cannabinoid that is primarily responsible for the psychoactive effects of cannabis.
Delta 9-THC is rapidly converted into 11-hydroxy-delta 9-THC, the metabolite that is active in the central nervous system (CNS).
Specific cannabinol receptors have been identified. The cannabinoid receptor, a member of the G-protein-linked family of receptors, is linked to the inhibitory G protein (Gi), which is linked to adenylyl cyclase in an inhibitory fashion.
Two known cannabinoid receptor subtypes have been identified, CB1 receptors and CB2 receptors. CB1 receptors are found predominantly at nerve terminals where they mediate inhibition of transmitter release. CB2 receptors occur mainly on immune cells, one of their roles being to modulate cytokine release.
The cannabinoid receptor is found in highest concentrations in the basal ganglia, the hippocampus, and the cerebellum, with lower concentrations in the cerebral cortex. This receptor is not found in the brainstem, a fact consistent with cannabis' minimal effects on respiratory and cardiac functions. Studies in animals have shown that the cannabinoids affect the monoamine and -aminobutyric acid (GABA) neurons.
A cannabis-related syndrome is the amotivational syndrome. Traditionally, the amotivational syndrome has been associated with long-term heavy use and has been characterised by a persons unwillingness to persist in a task, be it at school, at work, or in any setting that requires prolonged attention or tenacity. Persons are described as becoming apathetic and anergic, usually gaining weight, and appearing slothful.
