Researchers with the National Institute of Health and Medical Research, a French biomedical research institution, have recently discovered a molecule that protects the brain from cannabis intoxication, reports MedicalXpress. In other words, weed smokers everywhere may soon be able to toke up without getting stoned.

Preventing the high may seem to defeat the whole purpose of smoking for marijuana aficionados, but the end game for researchers is to develop a drug that can help treat cannabis dependence.

The molecule discovered by researchers is a steroid hormone called pregnenolone. It prevents a high by blocking the intoxicating ingredient found in cannabis, THC, from activating its brain receptor, the CB1 receptor. Though pregnenolone is produced naturally in the brain as a way to protect against overstimulation of the CB1 receptor, that defense is often overcome by ingestion or inhalation of marijuana.

Scientists uncovered the role of pregnenolone in the brain by giving rats equivalent doses of cocaine, morphine, nicotine, alcohol and cannabis and measuring the levels of several brain steroids produced in response to the drugs. They found that pregnenolone levels increased by as much as 3,000 percent in response to THC from cannabis. By artificially inducing greater concentrations of pregnenolone than is found naturally in the brain, researchers were able to reverse intoxication symptoms caused by THC. For instance, animals receiving pregnenolone treatment recovered their normal memory abilities, were less sedated and less inclined to continue to self-administer cannabinoids.

Researchers also tested the effects of pregnenolone on human CB1 receptors in cell cultures, and confirmed that the molecule should be able to reverse intoxication in humans much in the same way as it does with the rats.

One limitation to manufacturing pregnenolone as a drug is that it doesn't absorb easily when administered orally, but researchers are already developing more effective derivatives of the molecule.

"We have now developed derivatives of pregnenolone that are well absorbed and stable. They then present the characteristics of compounds that can be used as new class of therapeutic drugs," said Pier Vincenzo Piazza, one of the lead researchers on the study. "We should be able to begin clinical trials soon and verify whether we have indeed discovered the first pharmacological treatment for cannabis dependence."

Though marijuana is not considered a highly addictive drug, about 9 percent of those who use it regularly do become dependent on it. Worldwide, as many as 20 million people are believed to be addicted to cannabis. A drug that prevents users from getting stoned could go a long way to reducing that number.

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Bryan Nelson ( @@brynelson ) writes about everything from environmental problems here on Earth to big questions in space.

Molecule discovered that prevents weed smokers from getting stoned
Researchers hope a new drug can be developed to treat cannabis dependence.