Effects of benzodiazepines on taste aversions in a two-bottle choice paradigm

Diazepam (DZ) and chlordiazepoxide (CDP) were tested for their ability to antagonize LiCl-established conditioned taste aversions (CTAs) to saccharin in a two-bottle free-choice paradigm. CTAs to saccharin were established in male Sprague-Dawley rats on a chronic fluid-deprivation schedule by the administration of LiCl (3 mEq/kg, IP) following a forced-choice exposure to a novel saccharin solution (0.1%, w/v). Three days later, rats were provided with a two-bottle choice presentation of saccharin and distilled water. Conditioned rats drank distilled water almost exclusively while unconditioned animals preferred saccharin. Pretreatment with DZ (6, 9, 12 mg/kg, IP) and CDP (12 mg/kg, IP) significantly increased the saccharin intake of conditioned rats indicating an attenuation of the manifestation of the CTA. While these results are consistent with the known disinhibitory effects of benzodiazepines, alternative mechanisms involving polydipsia or interactions with the taste characteristics of saccharin could not be excluded. Both hypertonic saline (16%, w/v NaCl) and Barbital Sodium (100 mg/kg) produced polydipsia without attenuating CTAs suggesting that the two-bottle procedure is capable of distinguishing between polydipsic effects and anti-aversion effects for these drugs.