POTHEAD RATS STILL SMART

Study May Point Way To Ease Pain

Some St. Francis Xavier University lab rats have been getting high and
feeling no pain, all in the name of science.

John McKenna, a psychology professor at the Antigonish university, hopes
soon to publish a study showing rodents feel less pain after receiving a
marijuana-mimicking substance, while maintaining some other abilities.

"They don't look stoned at all," he said. "It's quite an exciting discovery."

Mr. McKenna, who heard Thursday his lab is getting more than $100,000 in
federal and provincial funding, started his study more than a year ago.

Although early testing shows results, he's careful about calling the
experiment a success.

"That's part of the scientific process. If you think that you found
something then you try and disprove it. If you can't disprove, then you go
ahead and publish your results."

He hopes to publish his findings in September.

What he's looking for is a painkilling compound that doesn't impair the
rats. He noted that morphine or other opiates block pain, but have harmful
side effects, such as slower heart rates or reduced motor skills.

In this experiment, he drills holes into drugged rats' skulls, inserts a
tube and, a week later, tests how they respond to pain while on a drug that
mimics marijuana.

The compound he uses is WIN-55,212 - an experimental substance supplied by
a British pharmaceutical company. He said it's more stable than THC, the
active ingredient in marijuana.

"I'm licensed to import the active ingredient," he said.

Mr. McKenna places rats under observation and uses tubes to inject
WIN-55,212. Then he applies a painful stimulus - akin to a bee sting - to
their feet.

Later, using infrared beams, he monitors how much the rats move around. A
snack placed inside the cage provides another incentive to move about.

"Do they move around in this environment and sniff it and investigate it or
. . . (get) stoned to the point they can't move?"

He's finding the rats' pain isn't stopping them from investigating while
under the influence. The study also tests to see whether the drug makes
rats overly active.

Mr. McKenna said the test might show something he finds quite exciting. "We
think we've discovered a new area of the brain that produces analgesia
(absence of pain)."

He said all mammals have similar brain structures, so the information will
likely be useful in fighting human pain.

Ottawa "seems to have a dire need for good scientific information about the
whole cannabis-medical marijuana issue. These findings can help."

John Cook, director of the Halifax branch of the Cannabis Buyers Club of
Canada, is hopeful the study leads to government action, but he's doubtful.

"Anything that convinces the government" to make it easier for those in
pain to get marijuana is good, he said. "The problem seems to be there are
studies for and studies against."