Stimulus properties of the selective 5-HT reuptake inhibitor fluvoxamine in conditioned taste aversion procedures

Previous attempts to train pigeons and rats to discriminate between the ant idepressant fluvoxamine and its vehicle as assessed in a drug discriminatio n paradigm have been without success. The present experiments were, therefo re, designed to assess in a conditioned taste aversion procedure (CTA) whet her or not fluvoxamine possesses stimulus properties. Rats were exposed to a conditioned taste aversion (CTA) procedure. In Experiment I, subjects wer e given 15 mg/kg fluvoxamine PO or vehicle after drinking a novel tasting s accharin solution. In Experiment II, a comparison was made between the effe cts of 15 mg/kg fluvoxamine IF, 30 mg/kg fluvoxamine IF, NaCl, and lithiumc hloride (LiCl). In Experiment III, subjects were treated with either 10 mg/ kg fluoxetine IF, 30 mg/kg fluvoxamine IF, or LiCl. CTA was observed after treatment with LiCl, but never after treatment with fluvoxamine or fluoxeti ne, suggesting that fluvoxamine does not have clear stimulus properties, wh ich can serve as a discriminative stimulus in operant procedures. In a cros sfamiliarization CTA procedure in mice, however, fluvoxamine elicited a rel iable CTA, suggesting that under certain conditions (species, dose?) select ive serotonin reuptake inhibitors (SSRIs) may lead to certain discriminable effects. It is as yet unclear why SSRIs apparently produce such weak and s pecies or situation-dependent discriminable. effects. (C) 1999 Elsevier Sci ence Inc.