Pubdate: Wed, 03 Oct 2001 Source: Reuters (Wire) Copyright: 2001 Reuters Limited Author: Will Boggs, MD MARIJUANA, COCAINE SHARE BRAIN TARGETS NEW YORK (Reuters Health) - The same brain cell targets that respond to marijuana are involved in the craving faced by cocaine addicts trying to quit, scientists say. The finding may help doctors come up with ways stop cocaine addiction, according to researchers from the Netherlands and the US National Institute on Drug Abuse. Dr. Taco De Vries from Vrije Universiteit in Amsterdam and associates studied the role of the cannabinoid system--the parts of the brain involved in our response to marijuana--to determine whether marijuana-like drugs or their inactive mimics would affect cocaine-seeking behavior in rats. SR141716A, a marijuana mimic that blocks the cannabinoid targets in the brain, significantly blocked cocaine-seeking behavior brought on by re-exposure to cocaine and by re-exposure to the cues associated with cocaine use, the investigators found. The mimic did not, however, reduce the cocaine-seeking behavior brought on by stress, according to the report in the October issue of Nature Medicine. In contrast, the researchers note, HU210 (a marijuana-like drug) actually caused a return of cocaine-seeking behavior. "The biggest problem of a drug addict is not the fact that he is taking drugs, but what happens if he is not taking the drug--when he or she feels the urge to take drugs," De Vries told Reuters Health. "In our opinion," De Vries added, "medication should be directed to control the drug-seeking part and not drug-taking part of this behavior." But so far there is no such effective medication. "Even though there are many social and psychological factors that can facilitate relapse, an agent that 'takes the edge off' craving would provide an invaluable complement to behavioral therapy and psychotherapy," adds Dr. Danielle Piomelli from University of California, Irvine, in a related commentary. "By unraveling the mechanisms in the brain that play a role in the persistence of drug-seeking behavior, we will be able to develop medication that may cure drug addicts," De Vries said. SOURCE: Nature Medicine 2001;10:1099-1100, 1151-1154. - --- MAP posted-by: Beth