miscellaneous bits and pieces from the past week or so…
By DAWN WALTON
Friday, October 14, 2005
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.”
and, almost exactly the same article from UPI:
By STEVE MITCHELL
Senior Medical Correspondent
WASHINGTON, Oct. 13 (UPI) — Scientists said Thursday that marijuana appears to promote the development of new brain cells in rats and have anti-anxiety and anti-depressant effects, a finding that could have an impact on the national debate over medical uses of the drug.
Other illegal and legal drugs, including opiates, alcohol, nicotine and cocaine, have been shown to suppress the formation of new brain cells when used chronically, but marijuana’s effect on that process was uncertain.
Now, a team led by Xia Zhang of the department of psychiatry at the University of Saskatchewan in Saskatoon may have found evidence the drug spurs new brain cells to form in a region of the brain called the hippocampus, and this in turn reduces anxiety and depression.
Marijuana appears “to be the only illicit drug whose capacity to produce increased … neurons is positively correlated with its (anti-anxiety) and anti-depressant-like effects,” Zhang and colleagues wrote in the November issue of the Journal of Clinical Investigation. The paper was posted online Thursday.
In the study, rats were given injections of HU210 — a synthesized version of a cannabinoid chemical found in marijuana — twice per day for 10 days.
Zhang told United Press International this would be “a high dose” of smoked marijuana, but he added he is not certain how many equivalent joints it would take or whether patients now using the drug typically would be getting this much HU210.
Although HU210 was injected, Zhang said there would be no difference if it was obtained by smoking marijuana.
The rats showed evidence of new neurons in the hippocampus dentate gyrus, a region of the brain that plays a role in developing memories.
Zhang’s team suspected the new brain cells also might be associated with a reduction in anxiety and depression, because previous studies had indicated medications used to treat anxiety and depression achieve their effect this way.
To find out, they treated rats with HU210 for 10 days and then tested them one month later. When placed in a new environment, the rats were quicker to eat their food than rats that did not receive the compound, which suggested there was a reduction in anxiety behaviors.
Another group of rats treated with HU210 showed a reduction in the duration of immobility in a forced swimming test, which is an indication the compound had an anti-depressant effect.
Asked how he thought the findings might impact the debate over using marijuana to treat medical conditions, Zhang said, “Our results indicate cannabinoids could be used for the treatment of anxiety and depression.”
He added that his view is “marijuana should be used as alcohol or nicotine,” noting “it has been used for treating various diseases for years in other countries.”
Last June the U.S. Supreme Court voted 6-3 that the federal ban on marijuana supersedes the laws of certain states that allow the substance to be used for medicinal purposes, such as the treatment of pain, nausea in cancer patients and glaucoma. Eleven states have passed laws legalizing marijuana use by patients with a doctor’s approval, including California, Alaska, Colorado, Hawaii, Maine, Montana, Nevada, Oregon, Vermont and Washington.
The Bush administration, through the Department of Justice’s Drug Enforcement Agency, began conducting raids in California in 2001 on patients using marijuana. Two of those arrested by the DEA — Angel Raich, who suffers from brain cancer, and Diane Monson, who used the drug to help alleviate chronic back pain — sued Attorney General John Ashcroft, requesting a court order to be allowed to grow and smoke marijuana, which led to the Supreme Court decision.
Paul Armentano, senior policy analyst with the National Organization for the Reform of Marijuana Laws, told UPI he thought the findings “would have a positive impact on moving forward this debate, because it is giving … a scientific explanation that further supports long-observed anecdotal evidence, and further lends itself to the notion that marijuana, unlike so many other prescription drugs and controlled substances, appears to have incredibly low toxicity and as a result lacks potential harm to the brain that many of these drugs have.”
The DEA Web site, however, contends that “marijuana is a dangerous, addictive drug that poses significant health threats to users,” including cancer and impaired mental functioning.
Armentano said this is a distortion of what scientific studies actually show. Studies in animals indicate marijuana actually may protect against many forms of cancer, rather than cause the disease, he said. In addition, studies in marijuana smokers have found little evidence of cognitive deficits, and even when they do, the defects disappear if the person stops smoking for 30 days.
Tri-Lamb Material 69% Nerd, 43% Geek, 65% Dork |
For The Record:
A Nerd is someone who is passionate about learning/being smart/academia. The classic, “80’s” nerd, you are what most people think of when they think “nerd,” largely due to 80’s movies like Revenge of the Nerds and TV shows like Head of the Class. You’re exceptionally bright and smart, and partly because of that have never quite fit in with your peers or social groups. Perhaps you’re realized, or will someday, that it is possible to retain all of the things that you like about being brilliant and still make peace with the social cliques around you. Or maybe you won’t–it’s really not necessary. As the brothers of Lambda Lambda Lambda discovered, you’re fine just the way you are and can take pride in that. I mean, who wants to be like Ogre, right!? Congratulations! |
Link: The Nerd? Geek? or Dork? Test written by donathos. |
You Are Likely an Only Child |
At work and school, you do best when you’re organizing. When you love someone, you tend to worry about them. In friendship, you are emotional and sympathetic. |
nope, i’m the oldest of four kids…
there’s another project that goes along with the performance of ORGAN2/ASLSP, sort of, which is The Clock of The Long Now, a mechanical clock that is designed to run for 10,000 years…
finally, Original Pussy Beer… i have in mind