Taste-potentiated odor aversion learning: role of the amygdaloid basolateral complex and central nucleus

The present study examined the relative contributions of the amygdaloid basolateral complex (ABL) and central nucleus (CN) to taste-potentiated odor aversion (TPOA) learning--an associative learning task that is dependent on information processing in two sensory modalities. In Experiment 1, rats with neurotoxic lesions of these systems were trained on the TPOA task by presenting a compound taste-odor conditioned stimulus, which was followed by LiCl administration. Results showed that ABL damage caused an impairment in potentiated odor aversion learning but no deficit in the conditioned taste aversion. In contrast, rats with CN damage learned both tasks. Experiment 2 examined the effects of ABL damage on TPOA and odor discrimination learning. The odor discrimination procedure used a place preference task to demonstrate normal processing of olfactory information. Results indicated that although ABL-lesioned animals were impaired on TPOA, there was no deficit in odor discrimination learning.