Central nervous system (CNS)

The central nervous system is the brain and spinal cord, the command center that processes sensation, thought, movement and the body's automatic functions.

The CNS is protected by the skull, the vertebral column, layers of membranes called meninges, and the blood-brain barrier, which controls which substances can pass from the bloodstream into brain tissue. It receives input from the peripheral nervous system, the nerves that run to the limbs, organs and skin, and sends instructions back out the same way. Neurons communicate across it using neurotransmitters such as glutamate, GABA, serotonin and dopamine.

Many conditions in a CBD glossary are CNS conditions, including epilepsy, multiple sclerosis, Parkinson's disease and migraine, and many drug effects such as sedation or somnolence are CNS effects. Cannabinoid receptor type 1 is one of the most abundant receptors in the CNS, which is why cannabinoids are studied for neurological questions. Most of that research remains early, and the only approved cannabinoid medicine for a CNS condition is a purified cannabidiol prescription for specific seizure disorders.