Augmented Accumbal Serotonin Levels Decrease the Preference for a Morphine Associated Environment During Withdrawal
Harris GC, Aston-Jones G
University of Pennsylvania,
VAMC 151 Rm A520,
University and Woodland Ave,
19104, Philadephia, PA, USA
Neuropsychopharmacology 2001 Jan 1; 24(1):75-85


Recent studies have found that acute morphine administration increases serotonin (5-HT) transmission within the nucleus accumbens and other forebrain regions. In contrast, 5-HT transmission is depressed during withdrawal from chronic morphine. We show that pharmacological agents that increase brain 5-HT levels (fluoxetine or 5-hydoxytryptophan, 5-HTP) abolish the preference of chronically morphine-treated, withdrawn rats for a morphine-associated environment. Similar results were seen when fluoxetine was microinjected into the nucleus accumbens. Conversely, rats given morphine acutely showed an enhanced preference for a morphine-associated environment when pretreated with these agents. Fluoxetine also decreased the heightened anxiety found in morphine withdrawn rats. The results of our study indicate that drugs that augment 5-HT levels may reduce the desire for morphine during withdrawal.
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