GAP43: A new cannabinoid CB1 receptor-interacting protein

The hemp plant (Cannabis sativa L.) has been used in medicine for at least fifty centuries. However, the chemical structure of its specific active components, the cannabinoids (9-tetrahydrocannabinol - THC and cannabidiol - CBD), was not elucidated until the early 1960s. Afterwards, two speci c G protein-coupled cannabinoid receptors were identi ed: CB1R, which is especially abundant in areasof the central nervous system (CNS) involved in the control of motor behaviour, learning and memory, or emotions; and CB2R, which is preferentially expressed in the immune system. These receptors are activated by endogenous ligands, the endocannabinoids (eCBs). By engaging CB1R in particular, both endogenous and exogenous cannabinoids exert pleiotropic, neuromodulatory effects on our brain. Particularly high levels of CB1R occur in the hippocampal formation, which shows a highly organized intrinsic circuit with the main purpose of memory consolidation..