Conditioned taste aversion induced by toluene administration in rats.

Effect of toluene as unconditioned stimulus in the conditioned taste aversion (CTA) learning in rats was investigated for a behavioral assessment of toluene toxicity. Intraperitoneal (200-800 mg/kg B.W.) and intravenous (20-40 mg/kg B.W.) administration of toluene induced dose-dependent CTA. Inhalation exposure to toluene at 1650-3300 ppm for 4 hr also induced moderate CTA. These results suggest that toluene functions as a "behaviorally aversive" stimulus and that the required dose for the conditioning varies with the route of administration. In addition, the interference effect of toluene vapor odor on the taste stimulus, which would reduce the strength of CTA, was examined but not revealed.