POT'S THC MAY WORSEN SEIZURES, DOCTOR SAYS

Finding in rats at odds with '80s research into epileptic grand mals

SASKATOON -- Marijuana researchers have found that a component of pot may
intensify the severity of the most common type of epileptic seizures.

The finding was a surprise for research leader Dr. Michael Corcoran at the
University of Saskatchewan, who said this week he expected findings would
support older research that had suggested high doses of THC, the
psychoactive ingredient of cannabis, could suppress grand-mal type seizures.

Now Corcoran suspects the effects of THC or its synthetic form, known as
cannabinoids, may depend on the part of the brain where the seizure occurs.

Corcoran's experiments on rats have shown seizures starting in the temporal
lobes of the brain appear to last longer and be more severe after
cannabinoids are administered.

He thinks studies conducted in the 1980s, which suggested some seizures may
be suppressed by marijuana, may have had a greater concentration of a THC
component that acts on a different part of the brain, the brain stem, where
grand-mal seizures originate.

Research conducted in the past decade has found that there are at least two,
and possibly three, different types of receptors on cellular membranes for
marijuana-like compounds, including some on nerve cells.

These "cannabinoid receptors" are normally acted upon by various naturally
occurring marijuana-like substances called "endogenous cannabinoids."

One of them has been aptly labelled andomide, a term derived from the
Sanskrit word meaning bliss, Corcoran said.

He added that identifying and cloning the receptor allowed researchers to
design artificial drugs that act selectively at that receptor to turn it on
or block the action of cannabinoids.

The results of the studies conducted in the 1980s were not particularly
impressive because they required such high doses that side effects resulted,
Corcoran said.

However, the view persisted that marijuana has potential as an
anti-epileptic agent that could be used in therapy. Though research on the
subject died out, some epileptics who cannot tolerate the normal
anti-convulsant drugs use marijuana to control seizures and with no
previously identified side effects.

While Corcoran is not prepared to dismiss the possibility that marijuana may
help control epilepsy, it is also possible users are experiencing a placebo
effect, he said.

"Our species is remarkably adept at kidding ourselves," he said.