Scientists Thursday said they have cloned a "button" that marijuana presses in the brain, a step that may lead to medications which mimic the drug's therapeutic effects without affecting mood or thinking.
New treatments for pain, high blood pressure, epileptic convulsions, nausea, asthma and the eye disease glaucoma may result, other scientists said.The new work revealed the chemical makeup of a protein structure on the surface of brain cells. Marijuana's main ingredient, called a cannabinoid, binds to this structure to exert its effects.
The study is presented in Thursday's issue of the British journal Nature by scientists from the National Institute of Mental Health in Bethesda, Md.
Their paper describes the brain-cell structure as it appears in rats, but further study showed the human structure is virtually identical, said study co-author Tom Bonner.
Marijuana is best known for producing a calm, mildly euphoric state. Time seems to slow down, and users become more sensitive to sights, sounds and touch. Ideas may flow rapidly through the mind while short-term memory is suppressed.
The new work opens the door to developing derivatives that produce medicinal effects without marijuana's undesired ones, said Dr. Solomon Snyder, director of the neuroscience department at Johns Hopkins Medical School in Baltimore.
The newly cloned structure is called a receptor. Many drugs and natural substances bind to particular receptors to exert their effects on the body.