Studies Find Rats Can Get Hooked on Drugs

[Guest guest]

> SSRI-Research

> Sun, 15 Aug 2004 15:58:49 -0400

 

> [sSRI-Research] Studies Find Rats Can Get

> Hooked on Drugs [or MORE ABUSE/CRUELTY TO ANIMALS]

>

> [-- *comments added below]

>

> Studies Find Rats Can Get Hooked on Drugs

>

> Fri Aug 13, 8:12 PM ET

>

> By LAURAN NEERGAARD, AP Medical Writer

>

> WASHINGTON - Rats can become drug addicts. That's

> important to know,

> scientists say, and has taken a long time to prove.

> Now two studies by

> French and British researchers show the animals

> exhibit the same compulsive drive

> [--not compulsive but dependent on for functionality]

> for cocaine [--and SSRI's]

as people do once they're truly hooked [-- have become

> adjusted to a chemical ].

>

> Only through experiments with addicted animals can

> scientists eventually

> learn what makes some people particularly vulnerable

> to addiction while

> others can quit at will, addiction specialists say.

>

> Addicted rats also could help uncover new anti-drug

> therapies [-- perhaps to

> get those of us addicted to an SSRI, off of one].

>

> Until now, scientists have been able to prove that

> rats will take drugs,

> even eagerly, but not that they're actually

> addicted. The new research was

> published Thursday in the journal Science.

>

> " What confers susceptibility to experimenting and

> trying drugs may be quite

> different than what changes your brain and leads to

> addiction, " explained

> Terry E. Robinson, a University of Michigan

> neuroscientist. " These articles

> provide us the approaches and the techniques to ask

> the latter. "

>

> " There's some fundamental shift " between casual drug

> use and addiction,

> added David Shurtleff, chief of basic neurological

> research at the U.S.

> National Institute on Drug Abuse. " Your brain has

> changed and that's

> manifest as a change in behavior. ... That's

> something new that's never

> really been nailed down in an animal model. "

>

> Among the ways to know when a rat's hooked: It keeps

> trying to get cocaine

> even when each hit comes with an electric shock.

>

> In the French study, rats poked their pointy noses

> through holes in their

> cages to trigger injections of cocaine. They were

> allowed access to the

> cocaine for three months, much longer than the 10-

> to 30-day drug-use

> studies normally done with animals.

> Compulsive drug-seeking even in the face of bad

> consequences is a measure of

> human addiction. So the researchers devised ways to

> measure that in animals:

> routinely cutting off the drug supply and measuring

> the rats' persistence at

> poking the supply trigger anyway, seeing how hard

> they worked to get the

> drug and noting whether they gave up when their feet

> were shocked.

>

> Intriguingly, 17 percent of the rats met all three

> measures and thus were

> considered addicted - while roughly 15 percent of

> human cocaine users become

> addicts [-- or 50% of all SSRI users], reported lead

> researcher Pier

> Vincenzo Piazza of INSERM, France's National

> Institute of Health and Medical

> Research.

>

> The British study focused just on the

> bad-consequences scenario. Rats who

> used cocaine for longer periods continued to do so

> even when their feet were

> shocked, reported Louk J.M.J. Vanderschuren, who led

> the study at the

> University of Cambridge. But rats who had used

> cocaine for a short period

> quit once they knew the punishment.

>

> Both studies concluded that extended exposure to

> cocaine is a key to

> addiction, but Piazza says that must be combined

> with some underlying

> genetic vulnerability - to explain why all the rats

> didn't succumb.

> " The huge question for the future, then, is what

> confers the

> susceptibility, " says Michigan's Robinson.

>

>

> 2004 The Associated Press. All rights

> reserved. The information

> contained in the AP News report may not be

> published, broadcast, rewritten

> or redistributed without the prior written authority

> of The Associated

> Press.

>