Marijuana might cause new cell growth in the brain

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-- Marijuana might cause new cell growth in the brain

Posted by Trancer-X on Oct-14-2005 18:27:

Marijuana might cause new cell growth in the brain

Marijuana might cause new cell growth in the brain

* 22:00 13 October 2005
* NewScientist.com news service
* Kurt Kleiner

A synthetic chemical similar to the active ingredient in marijuana makes new cells grow in rat brains. What is more, in rats this cell growth appears to be linked with reducing anxiety and depression. The results suggest that marijuana, or its derivatives, could actually be good for the brain.

In mammals, new nerve cells are constantly being produced in a part of the brain called the hippocampus, which is associated with learning, memory, anxiety and depression. Other recreational drugs, such as alcohol, nicotine and cocaine, have been shown to suppress this new growth. Xia Zhang of the University of Saskatchewan in Saskatoon, Canada, and colleagues decided to see what effects a synthetic cannabinoid called HU210 had on rats' brains.

They found that giving rats high doses of HU210 twice a day for 10 days increased the rate of nerve cell formation, or neurogenesis, in the hippocampus by about 40%.

Just like Prozac?

A previous study showed that the antidepressant fluoxetine (Prozac) also increases new cell growth, and the results indicated that it was this cell growth that caused Prozac�s anti-anxiety effect. Zhang wondered whether this was also the case for the cannabinoid, and so he tested the rats for behavioural changes.

When the rats who had received the cannabinoid were placed under stress, they showed fewer signs of anxiety and depression than rats who had not had the treatment. When neurogenesis was halted in these rats using X-rays, this effect disappeared, indicating that the new cell growth might be responsible for the behavioural changes.

In another study, Barry Jacobs, a neuroscientist at Princeton University, gave mice the natural cannabinoid found in marijuana, THC (D9-tetrahydrocannabinol). But he says he detected no neurogenesis, no matter what dose he gave or the length of time he gave it for. He will present his results at the Society for Neuroscience meeting in Washington DC in November.

Jacobs says it could be that HU210 and THC do not have the same effect on cell growth. It could also be the case that cannabinoids behave differently in different rodent species - which leaves open the question of how they behave in humans.

Zhang says more research is needed before it is clear whether cannabinoids could some day be used to treat depression in humans.

Journal reference: Journal of Clinical Investigation (DOI:10.1172/JCI25509)

http://www.newscientist.com/article...line-news_rss20

Posted by Lepanto on Oct-14-2005 18:36:

isn't this like a contradiction to all the burn outs ? wtf?

Posted by Shakka on Oct-14-2005 18:46:

Smoke 'em if you got 'em!

Posted by Yoepus on Oct-14-2005 18:49:

I dunno, maybe its just me but all the die-hard stoners I've met are quiet brain-dead.

Posted by Q5echo on Oct-14-2005 19:16:

i'm living proof that study is, so far, half assed.

Posted by josh4 on Oct-14-2005 19:35:

quote:
Originally posted by Yoepus
I dunno, maybe its just me but all the die-hard stoners I've met are quiet brain-dead.

aaahhh, as with most things in life, moderation is the key.

but it doesnt say it makes you smarter, or dumber, it just says it stimulates growth thats good for your brain. a healthy stupid brain is still going to be a stupid brain. lets also remember that another big effect of Marijuana is it slows the cognitive processes (which wears off as you come down) - so someone who is always stoned is going to be pretty slow mostly because well they're stoned

Posted by digitul punk on Oct-14-2005 22:33:

Now where did put my pipe at?

Intresting read but nothing special imo.

Posted by NebulousQ on Oct-15-2005 07:02:

Yeah, sure. Perhaps smoking weed does increase the regenerative rate of nerve cells/endings in the brain, but ,uh, how many did it kill off in the first place?

I'll place good money on the bet that the increased regeneration is going toward replacing cells you've already lost due to weed and the toxins there-in.

Posted by St_Andrew on Oct-15-2005 12:07:

Wohoooo

Posted by Trancer-X on Oct-15-2005 20:07:

quote:
Originally posted by NebulousQ
Yeah, sure. Perhaps smoking weed does increase the regenerative rate of nerve cells/endings in the brain, but ,uh, how many did it kill off in the first place?

I'll place good money on the bet that the increased regeneration is going toward replacing cells you've already lost due to weed and the toxins there-in.

Actually, that government propagandized theory that cannabis kills brain cells was debunked several years ago.

Posted by digitul punk on Oct-15-2005 21:41:

Have a source? I wanna read this.

Posted by NeoPhono on Oct-15-2005 21:58:

quote:
Originally posted by digitul punk
Have a source? I wanna read this.

He is right, as far as brain cells go. Cannabis works just like any other neurotransmitter-affecting drug. It binds to cannaboid receptors and ultimately increases dopamine release. Once those receptors are unbound, the effects are gone. Prior to 1988, before the THC receptor site was found in cells, the popular myth was that it physically affected neurons in order to have their effect. This idea has changed scientifically, but still lingers in popular belief.

Alcohol on the other hand, besides also affecting neurotransmitters, physically alters the structure of a cell's membrane, ion channels, enzymes and receptor sites. If you want to talk about a drug that kills brain cells look no further than alcohol.

*As an aside, I'm not saying that cannabis is completely harmless, there are other effects, such as from inhalation of smoke, that are harmful. However, to the brain itself, I have yet to read any current articles that say any long term neurological effects exist. When someone is "high" or going through a long period of cannabis use, they will have obvious cognitive function problems, but these wear off over time.

I'd also like to say that alcohol is one of the few drugs (along with barbituates) that can actually cause death from withdrawl. That alone should tell you the impact that alcohol can have in relation to illegal marijuana.

Posted by Trancer-X on Oct-15-2005 23:34:

quote:
Originally posted by digitul punk
Have a source? I wanna read this.

There were several studies done that debunked the myth. I'll find and post a few links. In the meantime...

quote:
MYTH: MARIJUANA KILLS BRAIN CELLS. Used over time, marijuana permanently alters brain structure and function, causing memory loss, cognitive impairment, personality deterioration, and reduced productivity.

FACT: None of the medical tests currently used to detect brain damage in humans have found harm from marijuana, even from long term high-dose use. An early study reported brain damage in rhesus monkeys after six months exposure to high concentrations of marijuana smoke. In a recent, more carefully conducted study, researchers found no evidence of brain abnormality in monkeys that were forced to inhale the equivalent of four to five marijuana cigarettes every day for a year. The claim that marijuana kills brain cells is based on a speculative report dating back a quarter of a century that has never been supported by any scientific study.

http://www.lindesmith.org/marijuana/factsmyths/

http://aje.oxfordjournals.org/cgi/c...y=4UzcqoQxcZdtY

http://www.pnas.org/cgi/content/full/95/14/8268

http://www.newscientist.com/channel/info-tech/dn7298

http://news.bbc.co.uk/1/hi/health/4286435.stm

There was also a good study done by Dr. William Slikker, Jr., but I still have to find it's contents.

Here's a link to a list of several more studies which I haven't had time to further delve into:

http://www.druglibrary.org/olsen/MEDICAL/paule.html

Posted by NebulousQ on Oct-16-2005 03:22:

^^^^^^

Hmmm. Did not know this. I learned something new.

Posted by Trancer-X on Oct-16-2005 06:26:

quote:
Originally posted

Here's a link to a list...

http://www.druglibrary.org/olsen/MEDICAL/paule.html

This is too funny.

From that list,

quote:
Chronic exposure to Delta-9-tetrahydrocannabinol fails to irreversibly alter brain cannabinoid receptors, by Tracy M. Westlake, Allyn C. Howlett, Syed F. Ali, Merle G. Paule, Andrew C. Scallet and William Slikker, Jr. Brain Research, Vol. 544

In other words, a group of scientists got together to see if they could shed their tolerances after quitting for little while.