Measures of the Aversive Effects of Drugs: A Comparison of Conditioned Taste and Place Aversions

Rationale. The present experiments directly compared the ability of the conditioned taste and place aversion designs (CTA and CPA, respectively) to measure the aversive effects of lithium chloride (LiCl) in male Sprague–Dawley rats. Methods. In the CTA assessment (Experiment 1), rats were given one of two novel tastes paired with LiCl (0, 0.18, 0.32, 0.56 or 1 mEq/kg) and the alternate novel taste paired with vehicle the next day. This was repeated three times, followed by a final two-bottle test. In the CPA assessment (Experiment 2), rats were given LiCl at the same doses and placed on one side of an unbiased two-chambered apparatus, followed by vehicle injection and placement on the opposite side on alternating days. This was repeated three times followed by free access to both sides in an assessment of relative preference. Results. LiCl induced robust, dose-dependent taste aversions with rats receiving 0.32 mEq/kg or greater consuming a smaller percentage of the drug-paired taste than that of controls. LiCl did not induce place aversions at any dose with LiCl- and vehicle-treated subjects displaying comparable preferences for the drug-paired side. The basis for the differences of the two designs in indexing LiCl's aversive effects was discussed.