Pubdate: Fri, 20 Jun 2003
Source: Athens Banner-Herald (GA)
Copyright: 2003 Athens Newspapers Inc
Contact:  http://www.onlineathens.com/
Details: http://www.mapinc.org/media/1535
Author: Kate Carter
Bookmark: http://www.mapinc.org/pot.htm (Cannabis)

RAT STUDY SHOWS USING DOPE KILLS BRAIN CELLS

University of Georgia research

Learn a lesson from rats: don't smoke dope and drive.

University of Georgia researchers have unveiled a study suggesting that
someone smoking marijuana might be able to do a task briefly, but could
experience serious long-term attention-span problems that interfere with the
successful completion of the task.

While this might not be a shocking revelation to some, said Jonathon
Crystal, a UGA assistant professor in psychology and the research leader,
the study shows that many tasks - like driving a car - can seem do-able for
someone under the influence of marijuana, when actually they are not.

"We gave the animals these marijuana-like compounds and it had a profound
effect on their ability to keep track of time. Before the drugs, they were
very good at the task - they were virtually perfect. While they were on the
drugs, their performance dropped substantially," said Crystal.

"... Probably the most telling part (of the study) is sustained attention.
Someone might think they could operate a car, and then it turns out they
can't."

The research was conducted on rats, but rather than coaxing the rats to
smoke a joint, the scientists injected the 300-gram subjects with a
synthetic, potent substance that is similar to tetrahydrocannabinol (THC),
the active ingredient in marijuana. The rats were trained to push levers
that corresponded with short and long noises in exchange for tasty morsels
of "rat chow." When they were under the influence, they forgot to pay
attention, and could no longer discriminate between long noises and short
bursts.

While the rats don't experience major physical changes when under the
influence, "they can look a little zoned, that's for sure," said Andrea
Hohmann, a UGA assistant professor of psychology who worked on the study.
She said the only real evidence of the rats' impairment was their inability
to complete the task they had been trained to do.

"Individuals might think they can write a term paper, for example, but in
actuality, they won't be able to do it," she said.

The study, funded by a federal grant of approximately $140,000 from the
National Institute on Drug Abuse, will be published soon in the journal
Behavioural Brain Research. One of the co-authors, Kenneth Maxwell, a UGA
research coordinator, said that when he tells strangers what his occupation
is, they almost never believe him.

"If I just say, 'I inject rats with drugs,' they say, 'No, you don't. Tell
me what you really do,'" he laughed.

Likewise, Hohmann said her students "get a laugh" out of the picture of "a
brain on drugs," and are generally surprised to hear that a human brain has
many cannabinoid receptors, which allow the body to produce its own
marijuana-like substance, helping to soothe pain.
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