Differential effects of amygdaloid lesions on conditioned taste aversion learning by rats

Rats with electrolytic lesions placed in either the basolateral or corticomedial divisions of the amygdala acquired a conditioned taste aversion to sucrose. Comparisons with a surgical control group indicated that damage to the corticomedial amygdala did not alter the animals' performance, while damage in the basolateral nuclei resulted in a small but significant attenuation of the aversion. Furthermore, these amygdaloid lesions did not alter the acceptability of two quinine hydrochloride solutions (0.01% and 0.001%). The daily drinking behavior of the rats with basolateral amygdaloid lesions appeared consistent with the hypothesis that this lesion affected the animals' appreciation of the novelty of the sucrose solution, and hence attenuated the subsequent aversion.