MARIJUANA COMPOUND SPURS BRAIN CELL GROWTH

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."

For more on the medical marijuana debate, check out the
MedicalMarijuanaProCon.org