In plying rats with cocaine, researchers have come together to define the boundary between drug use and addiction. Their study, published in tomorrow's issue of Science , shows that rats are looking more and more cocaine that if offered the drug for several hours.
George Koob, Professor of Neuropharmacology at The Scripps Research Institute in La Jolla, California, was intrigued by a study showing that some rats --- when offered as much cocaine they wanted for 3:00 - gradually increased their doses, while others remained stable. Seeking to crystallize the difference in doping styles and question the importance of the availability of cocaine, Koob and postdoctoral Serge Ahmed divided dozens of rats into two groups: one that could receive cocaine for 6 hours per day, another who had only an hour to get high. The rats had a lever they could support to receive a cocaine infusion painless intravenously.
Over a period of about 2 weeks, the rats of Group 6 hours gradually escalating cocaine use, until they are themselves both doses as often - about every 3 minutes - the rats of group 1 hour were. The results suggest that rats with restricted access to the drug were better able to control their use of it, while those with freer access abused. "There is a biological change that occurs somewhere in an animal that has access to the drug for a long period of time," says Koob, who believes that his animal model accurately describes the transition from drug use addiction
experts applaud the study while warning that the results may not apply to people. "I'm very impressed," said Klaus Miczek, professor of pharmacology at Tufts University in Medford, Massachusetts. However, he adds, "this is a rat model, not a primate model."
0 Komentar