Scientists find marijuana reduces memory impairment

As difficult as some of our readers might find it to believe, researchers have found that specific elements of marijuana can be good for the aging brain by reducing inflammation and possibly even stimulating the formation of new brain cells. The research suggests that the development of a legal drug that contains certain properties similar to those in marijuana might help prevent or delay the onset of Alzheimer's disease. If you can’t wait for the drug to be developed, and don’t fancy coping with getting stoned every morning, Science Magazine has an interesting article about an alternative – dramatically reducing your calorific intake is also beneficial for memory.

Though the exact cause of Alzheimer's remains unknown, chronic inflammation in the brain is believed to contribute to memory impairment.

Any new drug's properties would resemble those of tetrahydrocannabinol, or THC, the main psychoactive substance in the cannabis plant, but would not share its high-producing effects. THC joins nicotine, alcohol and caffeine as agents that, in moderation, have shown some protection against inflammation in the brain that might translate to better memory late in life.

"It's not that everything immoral is good for the brain. It's just that there are some substances that millions of people for thousands of years have used in billions of doses, and we're noticing there's a little signal above all the noise," said Gary Wenk, professor of psychology at Ohio State and principal investigator on the research.

Wenk's work has already shown that a THC-like synthetic drug can improve memory in animals. Now his team is trying to find out exactly how it works in the brain.

The most recent research on rats indicates that at least three receptors in the brain are activated by the synthetic drug, which is similar to marijuana. These receptors are proteins within the brain's endocannabinoid system, which is involved in memory as well as physiological processes associated with appetite, mood and pain response.

This research is also showing that receptors in this system can influence brain inflammation and the production of new neurons, or brain cells.

"When we're young, we reproduce neurons and our memory works fine. When we age, the process slows down, so we have a decrease in new cell formation in normal aging. You need those cells to come back and help form new memories, and we found that this THC-like agent can influence creation of those cells," said Yannick Marchalant, a study coauthor and research assistant professor of psychology at Ohio State.

Marchalant described the research in a poster presentation Wednesday (11/19) at the Society for Neuroscience meeting in Washington, D.C.

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