Separate neurophysiological experiments have shown that neurons responsive to taste and smell stimulation are coextensive within a circumscribed area of the orbitofrontal cortex. Other experiments have shown that this area receives substantial projections from established gustatory and olfactory areas of the brain. Because these previous neurophysiological studies did not test both gustatory and olfactory stimuli, it is not known whether functional integration of taste and smell occurs in the orbitofrontal cortex. This project will use electrophysiological and anatomical techniques to address the following issues: (1) Do the chemosensory neurons in the orbitofrontal cortex comprise a single convergent population, a mosaic of independent olfactory and gustatory elements, or two contiguous, but functionally distinct areas, and (2) Which areas of the brain project to the chemosensory area(s) within the orbitofrontal cortex? These experiments will contribute important information about the functional organization of orbitofrontal cortex, an area of the forebrain that may be relevant to certain pathological types of ingestive behavior (e.g. anorexia nervosa and bulimia) that require cortical involvement.
