Vagal circuitry mediating cephalic-phase responses to food

The dorsal vagal complex in the medulla oblongata is the hub of the central nervous system network that produces vagal cephalic-phase reflexes. The pr eganglionic motor neurons controlling these cephalic responses of digestion and metabolism are organized topographically in longitudinal columnar subn uclei in the dorsal motor nucleus of the vagus. Gustatory and other viscera l afferent inputs project into different subnuclei of thee nucleus of the s olitary tract capping the dorsal motor nucleus. Descending projections from more rostral stations of the neuroaxis project to the nuclei of the dorsal vagal complex, providing input both from exteroceptive senses, such as olf action and vision, and from forebrain areas that modulate reflex strength. Recent structural analyses of the dorsal vagal complex, as well as characte rizations of the region's inputs and neurochemistry, have provided a more c omplete understanding of the neural basis of cephalic-phase responses.