Buzzby

Adolescent Rats More Rattled By Marijuana
Paul Bonner | The Herald-Sun | 06/16/2006

DURHAM -- Marijuana may inhibit memory and learning -- at least temporarily -- to a greater degree in adolescents than in adults, according to a study by researchers at Duke University and the Durham Veterans Affairs Medical Center.

The research findings, published last week in the print edition of the journal Pharmacology, Biochemistry and Behavior and in an advance online edition in March, reported effects of tetrahydrocannabinol, the active ingredient in marijuana, in a series of experiments last year using rats.

Half of the nearly 200 rats were adolescent and half adult. All were male. When given THC, the adolescent rats took longer than the adults to remember where to swim in a shallow pool about 4 feet across to a small submerged platform.

When the platform was moved to a new location and raised above the water where the rats could see it, the younger ones still took longer to reach it.

In the memory test, adolescent rats took 64 percent longer than their elders to reach the platform. At higher concentrations of THC, the age difference in performance fell to 47 percent, as all the rats became more disoriented, the researchers said.

The effect disappeared when the rats were no longer under the influence of THC. Control rats that were not given THC learned to swim to the platform easily, said Young Ma Cha, the study's lead author.

An area of the brain similar in both rats and humans called the hippocampus is associated with spatial learning and memory. The researchers hypothesize that the effect of THC on it may be similar, said Scott Swartzwelder, a professor of psychiatry at Duke and the Durham Veterans Affairs Medical Center who was the study's senior author.

"The whole goal of this research program is to better inform the public, to have as a point of discussion something more than a slogan or scare tactics," he said.

(BuzzNote: That's because no one has ever guessed that people are forgetful when they're high. )

People's brains continue to develop and change throughout life, but young people's learning is foundational, the researchers said.

"I think the important thing is not to go too far in the sense of looking at 'How many joints is my son or daughter going to smoke before he or she becomes seriously impaired at studying?' " said Cha. "The idea is to look at the overall picture. Our younger rats, who model human adolescents, are showing serious impairment. That should definitely send a red flag to anyone who's thinking of using THC."

A representative of the National Organization for the Reform of Marijuana Laws in Washington, D.C., said the study appeared to turn little if any new ground, since the effect of THC on cognitive performance and even brain scans of human subjects including adolescents has been researched extensively for decades.

Those studies consistently have found no significant long-term impairment, said Paul Armentano, a senior policy analyst with NORML.

"Certainly, NORML does not believe, as any responsible organization, that the use of intoxicating substances, including marijuana, is a good idea for children to engage in," Armentano added.

Neither would the organization dispute that marijuana affects memory and learning while people are under its effect, he said.

Other researchers participating in the study include Duke and VA researchers Aaron White, Cynthia Kuhn and Wilkie A. Wilson.

Now they're doing similar experiments with female rats, Cha and Swartzwelder said.

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nerphroll

That's an interesting logical connection. Not quite sure how that one holds up to any test of validity, regardless of the researh results.

walstmonky

Maybe the young rodents were merely enjoying the water more than their elders.

casketfour

i hypothesis that everything happens for a reason and while short term memory is temporarily to some degree disabled while under the influence of thc (cannabis) that it cannot be without good cause perhaps this cause is something based emotionally such as teaching someone to get over some kind of trauma based deep in the subconscience I know I have experienced this first hand

I also find it funny that Duke was actually able to recive permission from the FDA to do research with the drug

dedbr

have been released if they were any other way but this?

I doubt it.....


some where in ded land....

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Though my soul may set in darkness,
It will rise in perfect light.
I have loved the stars too fondly,
To be fearful of the night." Sarah Williams

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Mamabudz

I love Rat experiments ...

But this one is as bogus as most!

...these are not happy rats...

They don't live in Rat Park

Then again...we don't live in Utopian Paradise either...but we can ...

Which brings us back to the Biblical aspects of our study.

chinbean

I wonder how the rats (young, old or middle aged) would perom under the influence of alchohol...

Mamabudz

these are not happy rats

...these are young gregarious and intelligent animals locked up in cages with other older males...stoned and then dumped into water.

And they did this again and again to test their reactions.

No hope of escape. No women.

Sort of sounds like Rat Gitmo.

Certainly no Rat Park.

And these were teen age males...

...I would say their survival instincts proved pretty strong to keep choosing to eventually return to the platform and continual torture rather than drown through "learned helplessness."

...I would like to imagine they were all properly thanked and retired t Rat Park but I know better...

...let's have a cookie and ponder that...

Tolerance4all

Did they use synthetic THC?

How much THC were the rats given?

They used THC only. How can they call this a valid study of Cannabis effects?
What about the other 399 chemicals? Could not these regulate or ameliorate the effects of THC on memory?

"The effect disappeared when the rats were no longer under the influence of THC"

So whats the point? Don't try to learn how to swim to a platform after smoking a fatty?

Buzzby

The pool at Gitmo has been closed for repairs. I understand that the hot tub is still available.

Rats are great swimmers. The young ones were probably more interested in paddling around than picking up the Rat Snacks™ on the island.