Bilateral electrolytic lesions of the nucleus of the solitary tract (NST) or ibotenic acid lesions of the pontine parabrachial nuclei (PBN) failed to disrupt retention of a preoperatively acquired conditioned taste aversion (CTA) to 0.3 M alanine. For both sham- and NST-lesioned rats, the CTA persisted following 3 nonreinforced conditioned stimulus (CS) presentations. For PBN-lesioned rats, retention was more labile. The preoperatively acquired CTA was extinguished by the 3rd nonreinforced CS exposure. When assessed postoperatively using a novel CS, NST-lesioned rats acquired a new CTA, although they were rendered anosmic with zinc sulfate (P. S. Grigson, T. Shimura and R. Norgren, 1997). Rats with PBN lesions, however, failed to acquire a second CTA postoperatively. Thus, the PBN is essential for the acquisition of a CTA, but neither of the brainstem gustatory nuclei need be intact for the retention of a preoperatively acquired CTA.
All Science Journal Classification (ASJC) codes
- Behavioral Neuroscience