Source: Independent, The (UK)
Contact:  http://www.independent.co.uk/
Pubdate: Sun, 19 Jul 1998
Author: Vanessa Thorpe

CHEMICALS HELP BRAIN DAMAGE AFTER A STROKE

Scientists at the United States National Institute of Mental Health
released research results last week which show that taking cannabis could
protect the brain from the damage inflicted by a stroke.

The chemicals examined, known as cannabinoids, are believed to work
independently of the more widely advertised euphoric effects of the
cannabis plant. After experimenting in the laboratory on the brains of
foetal rats, Aiden Hampson and his colleagues at the Washington-based
federal institute found that some of the cannabinoids acted as a useful
block to other more dangerous chemicals in the brain.

These toxic neurochemicals are the ones which systematically kill cells if
the oxygen supply is cut off, as, for example, the result of a blood clot
leading to a stroke.

Brain cells which are starved of oxygen release large amounts of glutamate,
a neurotransmitter or message-carrying chemical. This overstimulates nerve
cells and quickly kills them.

It has already been medically established for some time that other
chemicals in the group known as antioxidants can also counter this damaging
activity in the brain, but Hampson's team is now suspecting that
cannabinoids might prove just as, or even more, effective.

The two cannabinoids which were tested on the brains of rats were
cannabidiol and THC, the active ingredient in the drug that causes its
psychoactive effects.

It was the former, cannabidiol, which gave the scientists most cause for
hope. Unlike THC, it does not cause a "high" in the patient. "This is a
better candidate," said Mr Hampson, who suggests that, in the test tube at
least, the substance seemed to be both potent and protective. The federal
scientists' research was published in Tuesday's edition of the journal
Proceedings Of The National Academy of Sciences, and the article made it
clear that it is still too early to tell to what extent cannabidiol will be
able to help humans.

The scientists involved were also unable to confirm the idea that simply
taking the drug recreationally would afford some kind of protection against
brain damage in the event of a stroke.

Meanwhile, less authoritative research in the States is beginning to
indicate that some of the properties of cannabis might be used to help
people withdraw from addictions to cocaine and heroin. Veteran American
pro-cannabis campaigner Dana Beal is calling for more research to clarify
the positive uses of cannabis.

"This is further proof that the government has been consistently wrong to
connect cannabis use with those of harder drugs. Its effects are entirely
different and it may actually be possible to use it as part of a recovery
from addiction," he told the Independent on Sunday.

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Checked-by: (Joel W. Johnson)