[HenryVI]

Study turns pot wisdom on head
By DAWN WALTON
Friday, October 14, 2005 Posted at 3:57 AM EDT
From Friday's Globe and Mail

Calgary — Forget the stereotype about dopey potheads. It seems marijuana could be good for your brain.

While other studies have shown that periodic use of marijuana can cause memory loss and impair learning and a host of other health problems down the road, new research suggests the drug could have some benefits when administered regularly in a highly potent form.

Most "drugs of abuse" such as alcohol, heroin, cocaine and nicotine suppress growth of new brain cells. However, researchers found that cannabinoids promoted generation of new neurons in rats' hippocampuses.

Hippocampuses are the part of the brain responsible for learning and memory, and the study held true for either plant-derived or the synthetic version of cannabinoids.

"This is quite a surprise," said Xia Zhang, an associate professor with the Neuropsychiatry Research Unit at the University of Saskatchewan in Saskatoon.

"Chronic use of marijuana may actually improve learning memory when the new neurons in the hippocampus can mature in two or three months," he added.

The research by Dr. Zhang and a team of international researchers is to be published in the November issue of the Journal of Clinical Investigation, but their findings are on-line now.

The scientists also noticed that cannabinoids curbed depression and anxiety, which Dr. Zhang says, suggests a correlation between neurogenesis and mood swings. (Or, it at least partly explains the feelings of relaxation and euphoria of a pot-induced high.)

Other scientists have suggested that depression is triggered when too few new brain cells are created in the hippocampus. One researcher of neuropharmacology said he was "puzzled" by the findings.

As enthusiastic as Dr. Zhang is about the potential health benefits, he warns against running out for a toke in a bid to beef up brain power or calm nerves.

The team injected laboratory rats with a synthetic substance called HU-210, which is similar, but 100 times as potent as THC (delta-9-tetrahydrocannabinol), the compound responsible for giving marijuana users a high.

They found that the rats treated regularly with a high dose of HU-210 -- twice a day for 10 days -- showed growth of neurons in the hippocampus. The researchers don't know if pot, which isn't as pure as the lab-produced version, would have the same effect.

"There's a big gap between rats and humans," Dr. Zhang points out.

But there is a lot of interest -- and controversy -- around the use of cannabinoids to improve human health.

Cannabinoids, such as marijuana and hashish, have been used to address pain, nausea, vomiting, seizures caused by epilepsy, ischemic stroke, cerebral trauma, tumours, multiple sclerosis and a host of other maladies.

There are herbal cannabinoids, which come from the cannabis plant, and the bodies of humans and animals produce endogenous cannabinoids. The substance can also be designed in the lab.

Cannabinoids can trigger the body's two cannabinoid receptors, which control the activity of various cells in the body.

One receptor, known as CB1, is found primarily in the brain. The other receptor, CB2, was thought to be found only in the immune system.

However, in a separate study to be published today in the journal Science, a group of international researchers have located the CB2 receptor in the brain stems of rats, mice and ferrets.

The brain stem is responsible for basic body function such as breathing and the gastrointestinal tract. If stimulated in a certain way, CB2 could be harnessed to eliminate the nausea and vomiting associated with post-operative analgesics or cancer and AIDS treatments, according to the researchers.

"Ultimately, new therapies could be developed as a result of these findings," said Keith Sharkey, a gastrointestinal neuroscientist at the University of Calgary, lead author of the study.

(Scientists are trying to find ways to block CB1 as a way to decrease food cravings and limit dependence on tobacco.)

When asked whether his findings explain why some swear by pot as a way to avoid the queasy feeling of a hangover, Dr. Sharkey paused and replied: "It does not explain the effects of smoked or inhaled or ingested substances."

[Chicon]

There are a lot of different molecules in vegetals and some of them are 'good' for the brain. I guess there must be 'good' molecules in marijuana as in cocoa, spinash, tomato, ...

[Stoner]

Big Surprise!

LINK

Long-term marijuana use may fog the brain
excerpt>>>>>>

“It definitely fogs your brain,” says Lambros Messinis, who led the study at the University Hospital of Patras in Greece.

Messinis and colleagues tested the mental abilities of 20 long-term users who had taken marijuana heavily – smoking at least four joints a week – for an average of 15 years. Their brains were rustier than those of 20 short-term users – who had averaged seven years of use – and 24 controls who had used the drug sporadically or not at all.

“Importantly, we don’t know if it’s reversible,”

Like we didn't already know

[dugq]

Originally Posted by Stoner

Big Surprise!

LINK

Long-term marijuana use may fog the brain
excerpt>>>>>>






Like we didn't already know

What a pointless study. The participants were only given 24 hours without weed before testing. Theres little doubt that there is a detrimental effect in this short time period, however the vast majority of studies have shown the effect to be non-existent or negligible after 30 days of abstinence (I posted these studies in the other marijuana thread, can't be bothered posting them again). These researchers should have spent more time reading the existing literature.

As for weed making you smarter. I don't know, the study sounds a bit removed from everyday human cannabis use to be particularly valid

[Stoner]

What a pointless study.

You forgot the 'IMHO'

[valley]

I dont care what the study shows...I've known people who smoked pot for years and they clearly lost a bit of their sharpness, for lack of a better word. The ONLY benefits to pot smoking that I can see would be using it for certain illnesses.

side story....when I was sick and throwing up during my pregnancy, someone actually suggested to me that I try to smoke some pot...that it would settle my stomach! Forget about the fact that I have asthma and the fact that it might not be good for the baby. Apparently the desire to get rid of some temporary morning sickness was supposed to void all of the risks to myself and my unborn child! Some people!!!

[Stoner]

The ONLY benefits to pot smoking that I can see would be using it for certain illnesses.

Agree.

[Guyzer]

Originally Posted by dugq

What a pointless study. The participants were only given 24 hours without weed before testing. Theres little doubt that there is a detrimental effect in this short time period, however the vast majority of studies have shown the effect to be non-existent or negligible after 30 days of abstinence (I posted these studies in the other marijuana thread, can't be bothered posting them again). These researchers should have spent more time reading the existing literature.

As for weed making you smarter. I don't know, the study sounds a bit removed from everyday human cannabis use to be particularly valid

[Stoner]

I guess would be considered an opinion........ but are you humble?....

[Wiskycoo]

"There's a big gap between rats and humans," Dr. Zhang points out.

Thats the most important fact of that article. The fact that it is coming out of Calgary the biggest pothead province in Canada is another story all together. They are just looking for more reasons to make it legal. It should only be legal to people with serious illnesses like cancer.

It numbs your brain and for the most part are never again able to regain some of the quick response time you had, such as when speaking become unable to find certain words that before trying pot would not have been a problem.

[Guyzer]

Originally Posted by Stoner

I guess would be considered an opinion........ but are you humble?....

Humble... yes that's me. Study after study proves nada. It depends what side of the fence one is on.

Speaking from past experience smoke by itself causes no ill long term effects. I haven't done it in 25 years but bet your last peso I would if it were legal, studies be damned. Never seen anyone beat his wife or kids after smoking a joint. Also know lots of smart people in high places that smoked for years. Bet you know a few as well. BTW I don't drink either. Unless you want to count the beer I had last June after I mowed the lawn for the last time. I could tell you stories about the long term effects of booze but I won't as it's already been beat to death.

[Stoner]

Well, Wimpy...I have known people that have used alcohol, pot, various drugs...and even nothing, and been violent......but that's not what this thread is about.
The title of this thread: Marijuana good for the brain?????

And I posted a recent study that shows a different view than the thread starter.
You can counter it, as I did Henry's or agree, or post opinions.


you posted:

Also know lots of smart people in high places that smoked for years. Bet you know a few as well.

Yes, and the Mid East is facing a crisis because of that man's judgement.
Of course, I suspect it was more than pot, but I presume he had to start somewhere

I haven't done it in 25 years but bet your last peso I would if it were legal, studies be damned.

Thread's not about legalities .....studies..yes

Your opinion on the topic: "Speaking from past experience smoke by itself causes no ill long term effects. "


But....that's hardly scientific.
How do you know what your mental abilities or physical condition would be if never having used?

Maybe you could of been Prime Minister of Canada

[brindle]

I too have not smoked for twenty-five years and sure would be putting down the oil if only it was legal. Again I know some well off folks that smoke and they didn't become well off because they are brain dead, so much for clinical studies IMO.

"Yes, and the Mid East is facing a crisis because of that man's judgement.
Of course, I suspect it was more than pot, but I presume he had to start somewhere"

that's more about an addictive personality.

"How do you know what your mental abilities or physical condition would be if never having used?"
One person I know that smokes runs everyday and is a year round hiker. We should all be as fit.
Good enough for me.

[Wino]

If pot makes you brain dead, I would have automatically become a republican years ago.

[Gabriel]

It always made me paranoid...and I don't mean paranoid I was gonna get caught. Real paranoia. Like that people could see all my inner intent and thoughts...or like I was being followed and could never get away from the follower. Ugly stuff like that. YUK
I don't think it is good for my brain.