Recognition by Rats of Binary Taste Solutions and Their Components

• Published in: Chemical senses Vol. 41; no. 9; pp. 795 - 801
• Main Authors: Katagawa, Yoshihisa, Yasuo, Toshiaki, Suwabe, Takeshi, Yamamura, Tomoki, Gen, Keika, Sako, Noritaka
• Format: Journal Article
• Language: English
• Published: England 01.11.2016
• Subjects: conditioned taste aversion; 2 bottle preference test; binary taste mixtures; lick test
• ISSN: 0379-864X; 1464-3553
• DOI: 10.1093/chemse/bjw093

This behavioral study investigated how rats conditioned to binary mixtures of preferred and aversive taste stimuli, respectively, responded to the individual components in a conditioned taste aversion (CTA) paradigm. The preference of stimuli was determined based on the initial results of 2 bottle preference test. The preferred stimuli included 5mM sodium saccharin (Sacc), 0.03M NaCl (Na), 0.1M Na, 5mM Sacc + 0.03M Na, and 5mM Sacc + 0.2mM quinine hydrochloride (Q), whereas the aversive stimuli tested were 1.0M Na, 0.2mM Q, 0.3mM Q, 5mM Sacc + 1.0M Na, and 5mM Sacc + 0.3mM Q. In CTA tests where LiCl was the unconditioned stimulus, the number of licks to the preferred binary mixtures and to all tested preferred components were significantly less than in control rats. No significant difference resulted between the number of licks to the aversive binary mixtures or to all tested aversive components. However, when rats pre-exposed to the aversive components contained of the aversive binary mixtures were conditioned to these mixtures, the number of licks to all the tested stimuli was significantly less than in controls. Rats conditioned to components of the aversive binary mixtures generalized to the binary mixtures containing those components. These results suggest that rats recognize and remember preferred and aversive taste mixtures as well as the preferred and aversive components of the binary mixtures, and that pre-exposure before CTA is an available method to study the recognition of aversive taste stimuli.