Study shows marijuana increases brain cell growth

By Beeker · Oct 5, 2008 · ·
  1. Beeker
    [h2]science: Study shows marijuana increases brain cell growth [/h2]

    ST. JOHN’S, Nfld — Supporters of marijuana may finally have an excuse to smoke weed every day. A recent study in the Journal of Clinical Investigation suggests that smoking pot can make the brain grow.

    Though most drugs inhibit the growth of new brain cells, injections of a synthetic cannibinoid have had the opposite effect in mice in a study performed at the University of Saskatchewan. Research on how drugs affect the brain has been critical to addiction treatment, particularly research on the hippocampus.

    The hippocampus is an area of the brain essential to memory formation. It is unusual because it grows new neurons over a person’s lifetime. Researchers believe these new cells help to improve memory and fight depression and mood disorders.

    Many drugs -— heroin, cocaine, and the more common alcohol and nicotine — inhibit the growth of these new cells. It was thought that marijuana did the same thing, but this new research suggests otherwise.

    Neuropsychiatrist Xia Zhang and a team of researchers study how marijuana-like drugs — known collectively as cannabinoids — act on the brain.

    The team tested the effects of HU-210, a potent synthetic cannabinoid similar to a group of compounds found in marijuana. The synthetic version is about 100 times as powerful as THC, the high-inducing compound loved by recreational users.

    The researchers found that rats treated with HU-210 on a regular basis showed neurogenesis — the growth of new brain cells in the hippocampus. A current hypothesis suggests depression may be triggered when the hippocampus grows insufficient numbers of new brain cells. If true, HU-210 could offer a treatment for such mood disorders by stimulating this growth.

    Whether this is true for all cannabinoids remains unclear, as HU-210 is only one of many and the HU-210 in the study is highly purified.

    “That does not mean that general use in healthy people is beneficial,” said Memorial psychology professor William McKim. “We need to learn if this happens in humans, whether this is useful in healthy people, and whether THC causes it as well.”

    McKim warns that marijuana disrupts memory and cognition. “These effects can be long-lasting after heavy use,” he said. “This makes it difficult to succeed academically if you use it excessively.”

    “Occasional light use probably does not have very serious consequences. [But] there is some evidence that marijuana smoke might cause cancer.”

    Still, the positive aspects of marijuana are becoming more plentiful as further research is done. McKim says it’s not surprising that THC and compounds like it could have medicinal effects.

    “Many have been identified,” he said. “It stimulates appetite in people with AIDS, it is an analgesic, and blocks nausea in cancer patients undergoing chemotherapy. And it treats the symptoms of glaucoma.”

    The research group’s next studies will examine the more unpleasant side of the drug.

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  1. Wierd Logic
    Monkey don't care what the study says, smoking weed makes his memory absolutely awful.
  2. doggy_hat
    SWIM would have to agree, although it's only bad when he smokes. If he abstains for a while his memory returns to normal.
  3. Beeker
    SWIM will agree that while smoking memory function was way off.

    This article is about more about HU-210 research then plant smoking.
  4. Figaro
    WEll this Fish is trying to figure out if the study is saying that it makes the cells bigger or that it grow more brain cell. For example does marijuana make the cells from one inch cell into a 2 inche cell or does it multiply the amount of cells every time you smoke or at least at a certain rate of growth. Or was it both makes them bigger and grow more?

    Don't understand

    By the way marijuana may give your bad memory while under the influence, but I think I read that it improves your memory, I am assuming while not underthe influence.
  5. Heretic.Ape.
    ^ In answer to this question, this is one of the test animals

  6. psyche
    If you read the article, it also concludes that

    SWIM also suffers from memory problems after smoking much, but he thinks it is psychological. There was an excellent article somewhere in the forums about cannabis and memory. It noted that cannabis has only negative effects for some people, and further that it's because of the train of thought is more easily lost. When one is in a deeply relaxed state because of constant smoking and suddenly finds out that he can't remember something pretty simple, he becames agitated and gets locked. The 'on the tip of the tongue' -effect. It's kind of all in your mind, and not the drugs direct effect on brain functioning.

    Maybe this isn't the case for animals. I bet they never start thinking "shit, i really should remember this". Also sedentary lifestyle that cannabis might tempt some people to live is a sure way to diminish memory.
  7. Greenport
    SwiM's teacher used to know a student that used marijuana to help her study for her french class back in the day. According to the teacher, the student would smoke weed before studying say, an english/french list of words, and memorize while blazed out of her mind. While her memory was not all that great at the time, she would then wait about 2 hours and go over the list again - and she would have actually remembered it from earlier when she was stoned.

    Pot may help you get new brain cells, but in order for that to be a good thing people have to use them on something intelligent ;)

    SwiM feels like pot helps her to think about things more calmly but hazes her memory a little while on it.

    P.S.: This idea is nothing new - there was an article that came out a while back regarding the same subject. However swiM is glad that it's staying alive :) There needs to be more testing on this.
  8. Burnt
    there is a lot of evidence that cannabinoids do induce neurogensis in various parts of the brain.

    however this does not take away from the fact that THC and other cannabinoid agonists cause short term memory loss. the mechanism for this appears to be a reduction in acetylcholine efflux in the hippocampus (the same area these authors are noticing neurogensis).

    furthermore there is some evidence that the hippocampus shrinks with long term heavy (5 joints a day for many years) use.

    so far the literature evidence suggests THC causes short term memory problems (everyone knows this). although neurogenisis may be useful for marijuana to treat a variety of neurogenerative diseases, which is currently heavily under investigation by the scientific and pharmaceutical communities. so yes the government is lieing when they say weed has no medical value.

    when reading these neurochemistry papers be aware results often depend on the type of assay being performed, the organism they are being performed in, and the dose of chemicals being used.
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