COCAINE WITHDRAWAL REDUCES DOPAMINE TRANSPORTER BINDING IN THE SHELL OF THE NUCLEUS-ACCUMBENS

We have previously shown that withdrawal from repeated, intermittent i nfusions of cocaine in Lewis rats results in a long-lasting reduction in dopamine transporter levels in the nucleus accumbens. The reduction is dose-dependent, requires multiple injections as well as about a 10 -day withdrawal period. In this investigation, we show that the decrea se (34%) occurs in the shell rather than in the core of the nucleus ac cumbens, and that a second cycle of cocaine administration and withdra wal has no additional effect. Also, there were no changes in transport er binding in the caudate putamen, the olfactory tubercle or the ventr al tegmental area. These results indicate that the limbic portions of the nucleus accumbens are involved in neurochemical adaptations during withdrawal from cocaine. (C) 1996 Wiley-Liss, Inc.