Neuroscientists Discover How the Brain is Stimulated by Marijuana
Researchers Suggest That The Body Uses a Natural Form of Marijuana
By Philip J. Hilts
Special to The New York Times
WASHINGTON – Researchers plan to report that they have discovered receptors in the brain that are stimulated by marijuana, suggesting that there is a previously unknown chemical pathway in the body using a natural form of the herb. The work suggests that researchers might eventually be able to develop drugs that do not cause intoxication but have some of the medicinal properties of the marijuana plant, including pain relief, anti-asthmatic, anti-nausea and anti-convulsive action. Researchers might also be able to design entirely new drugs aimed at these receptors that are more effective painkillers.
“This opens up a whole new system in the body,” said Dr. Louis Harris, chairman of pharmacology and toxicology at the Medical College of Virginia, whose laboratories have worked on the problem. A receptor is a molecule on a cell surface where a substance attaches itself to create an effect, acting like a lock and key. The discovery of such a molecule occurring naturally in the body means that the body makes a substance like marijuana.
A similar discovery two decades ago opened up much of the current work on receptors, when Dr. Solomon Snyder, a John Hopkins University neuroscientist, and his colleagues located the receptor where heroin, morphine and other opiates act. It was later found that there were “natural opiates,” called enkephalins, which the body uses to relieve pain and stress.
Natural substances that have such powerful action have enormous potential, said Dr. Julius Axelrod, a chemist from the National Institute of Health. He said the natural substances could be used to make more effective drugs. “This is a very exciting finding,” said Dr. Axelrod, who predicted that many laboratories would begin a search for the “natural marijuana” that the body produces. The discovery was reported recently at a meeting at the National Academy of Sciences’ Institute of Medicine, which designated the 1990s as the “Decade of the Brain.”
Dr. Snyder reported that Dr. Michael Brownstein, chief of the laboratory of cell biology at the National Institute of Mental Health, had discovered the receptor. Dr. Brownstein declined to discuss the work, which he has submitted for publication in the British journal Nature. Dr. Snyder said the work opens up another natural chemical pathway for relieving pain.
Dr. B.R. Martin, of the Medical College of Virginia, who has worked for years to find a marijuana-derived pain reliever without the herb’s side effects, said, “This is important because these cannabinoid compounds are unique. A drug to come out of this would not be just another ‘me-too’ drug, but would use a completely different mechanism to deal with pain, unlike that of the natural opiates. We have been waiting for this for years,” said Dr. Martin.
The body uses an array of hormones, neurotransmitters, and other chemicals to trigger effects – like the reactions that come with anger – or to regulate the operation of different organs, like the regular beat of the heart. The chemicals the body uses to do this act by being released from one cell and binding to another. In the case of the just-discovered receptor, one of the effects may be the release of a mild, natural painkiller.
“Humans didn’t evolve a receptor for some chemical out of a plant,” said Dr. Harris, “and it’s not just an accident that they fit. The body makes these receptors to accept chemicals that are important.” The “natural marijuana” receptor has been found primarily in the regions of the brain where higher mental activity takes place, not where lower functions such as heartbeat are controlled. Psychotropic drugs like heroin, amphetamines and cocaine affect lower-brain activities like heartbeat and respiration “in dangerous ways,” he said.
Marijuana, or its active ingredient THC (tetrahydrocannabinol), has a number of interesting effects that researchers would like to study. It has effects at doses that are very low compared to the doses at which life-threatening complications might occur. In addition to causing euphoria and a number of other psychological effects, it can be used to retard glaucoma, to treat asthma, to stop seizures, to lower blood pressure, and other positive effects.
It is often the case that the different effects a drug has are triggered by different subgroups of the main receptor, Dr. Snyder said, so that discovery of the main receptor is likely to lead to a family of other receptors whose functions are somewhat different. One thing that may be found is an antagonist that reverses the effect of THC. It is not clear if the discovery would have much in drug treatment, however, because marijuana is not addictive and therefore little would be gained by blocking its action, as methadone blocks the action of heroin.
Officials of the National Institute of Mental Health refused to discuss the research, saying that the editors of Nature had asked them not to discuss it before its scheduled publication in the next few weeks.
I believge that quality has alot to do with your high also. are you saying if one meditates breathes properly than the effects of weed will be different? I have notice when your in higher natural consciousness your pscho high is beter.
)...so i'm not convinced of the validity of this so called syndrome as of yet...i did see dave chappelle go through a stint like the one described in the first post of this thread in the movie half baked...imho, different people handle weed in different ways, i believe it depends on the chemical make-up of your body, the frequency that you smoke and the stength of your mental powers...2 each their own though...
