Taste and olfactory status in a gourmand with a right amygdala lesion

Gray matter volumes of early sensory regions are associated with individual differences in sensory processing

Sensory processing (i.e., the manner in which the nervous system receives, modulates, integrates, and organizes sensory stimuli) is critical when humans are deciding how to react to environmental demands. Although behavioral studies have shown that there are stable individual differences in sensory processing, the neural substrates that implement such differences remain unknown. To investigate this issue, structural magnetic resonance imaging scans were acquired from 51 healthy adults and individual differences in sensory processing were assessed using the Sensory Profile questionnaire (Brown et al.: Am J Occup Ther 55 (2001) 75-82). There were positive relationships between the Sensory Profile modality-specific subscales and gray matter volumes in the primary or secondary sensory areas for the visual, auditory, touch, and taste/smell modalities. Thus, the present results suggest that individual differences in sensory processing are implemented by the early sensory regions. Hum Brain Mapp 38:6206-6217, 2017. © 2017 Wiley Periodicals, Inc.

Effects of lesions in different nuclei of the amygdala on conditioned taste aversion

Conditioned taste aversion (CTA) is an adaptive learning that depends on brain mechanisms not completely identified. The amygdala is one of the structures that make up these mechanisms, but the involvement of its nuclei in the acquisition of CTA is unclear. Lesion studies suggest that the basolateral complex of the amygdala, including the basolateral and lateral amygdala, could be involved in CTA. The central amygdala has also been considered as an important nucleus for the acquisition of CTA in some studies. However, to the best of our knowledge, the effect of lesions of the basolateral complex of the amygdala on the acquisition of CTA has not been directly compared with the effect of lesions of the central and medial nuclei of the amygdala. The aim of this study is to compare the effect of lesions of different nuclei of the amygdala (the central and medial amygdala and the basolateral complex) on the acquisition of taste aversion in male Wistar rats. The results indicate that lesions of the basolateral complex of the amygdala reduce the magnitude of the CTA when compared with lesions of the other nuclei and with animals without lesions. These findings suggest that the involvement of the amygdala in the acquisition of CTA seems to depend particularly on the integrity of the basolateral complex of the amygdala.