Cannapedia Encyclopedia of cannabis strains

Cannabinoid Receptors

Two major receptors forming the endocannabinoid system are cannabinoid receptors CB1 and CB2. An orphan receptor GPR55 is newly considered the third receptor responding to endo- and phytocannabinoids. All these receptors are made from transmembrane proteins that can transfer extracellular signals into intracellular space.


CB1 receptors are mostly utilized in the brain, and their distribution throughout the human body has been thoroughly described: they are mostly present in the hippocampus, basal ganglia, cerebral cortex and in cerebellum.

CB1 receptors are to a lesser extent also present in the amygdala, hypothalamus, nucleus accumbens, thalamus, grey matter, and in spinal cord, but also in different areas of the brain, mainly in cerebrum and diencephalon. They can be also found in many peripheral organs.


Distribution of CB2 receptors is different, and it is limited mostly to cells of the immune system, such as macrophages, neutrophils, monocytes, B lymphocytes, T lymphocytes and microglia. Recently, CB2 receptors also turned out to be present in nerve fibres of the skin and in keratinocytes and bone cells such as osteoblasts, osteocytes and osteoclasts, liver and in pancreatic cells that secrete somatostatin. CB2 receptors were also found in the central nervous system, astrocytes, microglia, and in neurons of the brain stem.

Kanabinoidní receptory