ABSTRACT
This chapter provides an overview of the ascending projections from the solitary tract nucleus to demonstrate that the nucleus tractus solitarius (NTS) participates in neuronal networks capable of producing widespread orofacial, autonomic, neuroendocrine, and behavioral responses. The solitary tract nucleus has three major subdivisions, the rostral gustatory, intermediate, and caudal autonomic parts. The caudal part of the nucleus tractus solitarius receives afferent innervation from all major organs in the body and, as such, it is the major visceral sensory relay group in the brain. Efferent fibers from the NTS which originate in the caudal and intermediate subdivisions first take an ascending course within the nucleus of the solitary tract. Projections from the rostral, gustatory NTS are found in the caudomedial parts of the parabrachial nuclear complex complex, in the “waist” area, and the medial, external medial, ventral, and centrolateral parabrachial subnuclei.
