title: Orosensory and Homeostatic Functions of the Insular Taste Cortex.
abstract: The gustatory aspect of the insular cortex is part of the brain circuit that controls ingestive behaviors based on chemosensory inputs. However, the sensory properties of foods are not restricted to taste and should also include salient features such as odor, texture, temperature, and appearance. Therefore, it is reasonable to hypothesize that specialized circuits within the central taste pathways must be involved in representing several other oral sensory modalities in addition to taste. In this review, we evaluate current evidence indicating that the insular gustatory cortex functions as an integrative circuit, with taste-responsive regions also showing heightened sensitivity to olfactory, somatosensory, and even visual stimulation. We also review evidence for modulation of taste-responsive insular areas by changes in physiological state, with taste-elicited neuronal responses varying according to the nutritional state of the organism. We then examine experimental support for a functional map within the insular cortex that might reflect the various sensory and homeostatic roles associated with this region. Finally, we evaluate the potential role of the taste insular cortex in weight-gain susceptibility. Taken together, the current experimental evidence favors the view that the insular gustatory cortex functions as an orosensory integrative system that not only enables the formation of complex flavor representations but also mediates their modulation by the internal state of the body, playing therefore a central role in food intake regulation.
authors.affiliation: The John B. Pierce Laboratory, School of Medicine, Yale University, 290 Congress Avenue, New Haven, CT 06519, USA. Department of Psychiatry, School of Medicine, Yale University, 300 George Street, Suite 901, New Haven, CT 06511, USA.
authors.forename: Ivan E
authors.initials: IE
authors.lastname: de Araujo
authors.affiliation: The John B. Pierce Laboratory, School of Medicine, Yale University, 290 Congress Avenue, New Haven, CT 06519, USA. Department of Psychiatry, School of Medicine, Yale University, 300 George Street, Suite 901, New Haven, CT 06511, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Geha
authors.affiliation: The John B. Pierce Laboratory, School of Medicine, Yale University, 290 Congress Avenue, New Haven, CT 06519, USA. Department of Psychiatry, School of Medicine, Yale University, 300 George Street, Suite 901, New Haven, CT 06511, USA.
authors.forename: Dana M
authors.initials: DM
authors.lastname: Small
keywords: Energy homeostasis; Feeding; Flavor; Insular cortex; Multisensory integration; Orosensation; Taste