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Abstract

A combination of functional and anatomical methods was used to help localize the representation of gustatory and interoceptive processes in the macaque cortex. Under anesthesia, neuroimaging (fMRI) and electrophysiology experiments were conducted during a series of functional stimulation paradigms, which included the application of different tastants (sour, sweet and salt) and distention of the lower gastrointestinal tract. The resulting BOLD activity in key subcortical (e.g. PAG, PbN, thalamus, amygdala) and cortical (e.g. insula, cingulate, SFG) structures was examined in an effort to delineate the sensory afferent relays and elucidate the connectivity between the primary cortical recipient of visceral and gustatory information – the insular cortex – and associated regions involved in the maintenance of homeostasis and the manifestation of emotional and cognitive percepts related to the elicited bodily sensations. Whole-brain fMRI analyses eventually developed into a more refined sampling of the insular cortex by electrophysiology, which identified neuronal population activities underlying such functional processes.