Research teams from the Drug Abuse Program of the VU Medical Center in the Netherlands and the intramural laboratories of the National Institute on Drug Abuse (NIDA) have identified a process in the brain that may lead to a new generation of medications to prevent relapse to cocaine use.
In studies using rats, the scientists, led by Dr. Taco J. De Vries of VU Medical Center and Dr. Yavin Shaham of NIDA, found that the same system -- the cannabinoid system -- that governs the pharmacological actions of marijuana in the brain also plays an important role in the neuronal processes underlying relapse to cocaine use. By blocking cannabinoid receptor activity with chemical antagonists, the investigators prevented relapse to cocaine use induced by exposure to cocaine-associated cues or by cocaine itself.
NIDA Director Dr. Alan I. Leshner says, "This finding could open up a new avenue for the development of drugs to prevent relapse to cocaine use induced by environmental cues. Treatment of cocaine addiction has always been hampered by high rates of relapse, even after prolonged drug abstinence, and this research could be the first step in the development of a new medicinal approach to make it easier for a recovering addict to remain drug-free."
Dr. De Vries of the Dutch research team says that findings from this and other experiments indicate that the CB1 cannabinoid receptor is a promising target for a pharmacological intervention to prevent relapse to cocaine seeking. In this study, according to Dr. De Vries, the CB1 receptor antagonist, SR141716A, administered to the rats reduced relapse to cocaine-seeking behavior in two of the three most common conditions associated with relapse: exposure to stimuli or environmental cues previously associated with cocaine use and exposure to cocaine itself. It had no effect on relapse triggered by stress.
The study is published in the October 1 issue of Nature-Medicine.