Canvassing for Opinion - aka "Blairs Brain on Cannabis"

IMHO prohibition sentiment requires inherent addiction to status quo, an incapacity to visualise beyond the here and now and a desperate desire to know others might feel the same... Reform is not revolutionary, rather it is evolutionary. Having survived banging your head against a brick wall the evolutionist relishes having stopped. / Blair

Saturday, October 15, 2005

Cannabinoids and neurogenesis [Eurodrug]

Predictably the media follows the story of the brain's cannabis and chemistry, the gradient of truth slopes towards reform daily - this time from our side of the ledger of benefits and harms.

The more we know, the more unjust this law becomes.

New Scientist, Globe and Mail (Canada) and Forbes all well worth a read, the spin "ours is 100 times more potent than your pot" pot is the gist of it, while logic and anecdote suggests the herb reliably reports efficacy at 1% on their data, or two orders of magnitude more powerful 'in effect' than its synthetic and all at near zero cost.

Could such a perfect pill exist?


-------- Original Message --------
Subject: [Eurodrug] WILD! Forthcoming study - cannabinoids and neurogenesis
Date: Fri, 14 Oct 2005
From: andria efthimiou

New Scientist

The Journal PDF.

Matt Paul Armentano wrote:
Expect to see some of the wires this afternoon/evening report on a preclinical study (to be published in the Journal of Clinical Investigationfinding that the administration of synthetic cannabinoids promotes embryonic and adult hippocampus neurogenesis in rats.

See also: Globe and Mail, Science and Health

Study Turns Pot Wisdom on Head By Dawn Walton Source: 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."
==================== ends ==================================

Forbes Magazine HealthDay News
Marijuana Compound Spurs Brain Cell Growth
By Alan Mozes, HealthDay Reporter

When it comes to the controversy surrounding medical marijuana, an international team of researchers is busy stirring the pot by releasing findings that suggest the drug helps promote brain cell growth while treating mood disorders. According to the study in rats, a super-potent synthetic version of the cannabinoid compound found in marijuana can reduce depression and anxiety when taken over an extended period of time. This mood boost seems to be the result of the drug's ability to promote the growth of new brain cells, something no other addictive drug appears able to do, the researchers say. The findings, which appear in the November issue of the Journal of Clinical Investigation, remain preliminary, however.

"Our results were obtained from rats, and there's a big difference between rats and humans," said study co-author Dr. Xia Zhang, of the neuropsychiatry research unit in the department of psychiatry at the University of Saskatchewan in Saskatoon, Canada. "So, I don't really don't know yet if our findings apply to humans. But our results indicate that the clinical use of marijuana could make people feel better by helping control anxiety and depression."

The new findings come on the heels of a U.S. Supreme Court ruling in June granting federal authorities the power to stop doctors from prescribing marijuana. That decision also bars individuals from cultivating the herb for medical purposes. The decision overrides laws currently on the books in 11 states which had legalized the use of marijuana for patients receiving a doctor's approval. According to the ruling, the Supreme Court justices made their decision on the basis of interstate commerce regulations rather than on an evaluation of the pros and cons of medical marijuana use.

But does medical marijuana work? To help settle that question, Zhang's team focused on the potential of a synthetic laboratory-produced form of the cannabinoid compound naturally found in the marijuana plant. Humans and other animals also naturally produce the compound, and are known to have cannabinoid receptors lying on the surface of cells in the nervous system and the immune system. Prior research has shown that, when exposed to cannabinoids, these receptors can provoke an anti-inflammatory and anti-convulsive response. They can also instigate a range of psychotropic effects such as euphoria. The current study focused on a particular formulation of synthetic cannabinoid known as HU210 -- a compound which Zhang described as the most powerful cannabinoid in the world.

The authors explored both the short-term and long-term effects of exposure to HU210 in rats. To measure the drug's short-term response, they gave adult rats a single injection of HU210. To study the same drug's effect over the longer term, the researchers gave a separate group of adult rats twice-daily injections of the cannabinoid over a two-week period. Autopsies revealed that by the end of the 10-day HU210 treatment regimen, new neurons had been generated and integrated into the circuitry of the hippocampus region of the rat's brains. This process, known as neurogenesis, was still in evidence a full month after treatment had been initiated.

Neurogenesis was not triggered in response to brain cells being killed through cannabinoid exposure, the researchers add. In fact, HU210 injections did not appear to prompt any loss of neurons in the hippocampus. Cannabinoid use appeared to boost mood, as well: According to the scientists, behavioral tests suggest that long-term treatment reduced the rodent's anxiety- and depression-linked behaviors. For example, one month post-treatment, treated rats deprived of food for 48 hours were quicker than similarly deprived, non-treated rats to begin eating food when it was finally offered to them in an unfamiliar environment.

The researchers believe treated rats may have been less anxious in the manner they handled this novel situation. They stress the results were not related to cannabinoids' appetite-stimulating effects, since the treated rats' eating behavior was similar to that of untreated rats when they were offered food in a familiar setting. Treated rats also responded in a less anxious manner to swimming and climbing tests, and displayed shorter periods of immobility compared with untreated rats. The latter finding was interpreted to mean that HU210 had an antidepressant effect on rats receiving the cannabinoid over the longer term.

However, while long-term administration of higher doses worked to reduce anxiety and depression, lower doses did not appear to have the same effect, the researchers added. Zhang and his associates credit cannabinoid-linked neurogenesis with the apparent mood shifts seen in the animals. The hippocampus area of the brain where the neuronal growth occurred is key to the regulation of stress and other mood disorders, Zhang's team point out. This region is also important to the control of cognitive processes such as learning and memory. Among the common addictive drugs, marijuana alone appears able to promote neurogenesis when used over time and in the right dosage, the researchers say.

In contrast, prior research has demonstrated that chronic administration of cocaine, opiates, alcohol and nicotine inhibits brain cell growth. "If our results can be confirmed in humans, we should anticipate the chronic use of marijuana as a medical treatment for anxiety and depression," Zhang said. However, he cautioned that "this treatment is not the same as smoking marijuana. Whether smoking marijuana can produce the same effect, we just don't know." Dr. Perry G. Fine, a professor of anesthesiology at the University of Utah School of Medicine Pain Research Center, said more than enough data has already been gathered to confirm medical marijuana's potential benefits. "It's great that there's new science, but to me this is no longer an epiphany," he said. "It's just proving what's been long-suspected. We're behind the curve with the cannabinoids largely because of the stigma of marijuana going years and years back." "I think most people with clinical expertise in the area of palliative medicine know that if patients had access to all the tools we currently have, we could certainly do a whole lot better to help people live with multiple chronic diseases," he added. "The social policies are way behind our technology, and that's where we need some catching up."

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