Within-event learning in rats with lesions of the basolateral amygdala

▸ We examine BLA- and sham-lesioned rats’ ability to form sensory–sensory associations. ▸ BLA-lesioned rats can acquire sensory preconditioning. ▸ BLA-lesioned rats are impaired at taste-potentiated odor aversion. ▸ BLA needed for learning sensory properties of motivationally significant stimuli. Rats with neurotoxic lesions of the basolateral amygdala were trained in procedures designed to assess the formation of within-event, taste–odor associations. In Experiments 1 and 2 the animals were given initial exposure to a taste–odor compound; the value of the taste was then modified, and the consequent change in responding to the odor was taken to indicate that an odor–taste association had been formed. In Experiment 1 the value of the taste (saline) was enhanced by means of salt-depletion procedure; in Experiment 2 the taste was devalued by aversive conditioning. In neither procedure did lesioned animals differ from sham-operated controls. Experiment 3 confirmed, however, that taste-potentiation of odor aversion learning (an effect thought to depend on the formation of a taste–odor association) is abolished by the lesion. Implications for the view that the amygdala is necessary for sensory–sensory associations between events in different modalities are considered.