ABSTRACT
The vagus nerve, as its name implies, is the largest and most extensively ramifying nerve of the autonomic nervous system; it is involved in conveying information to and from most of the viscera of the thorax and abdomen as well as many structures of the head and neck. This chapter reviews the literature pertaining to the latter question and speculates on how the vagus nerve can interact with other brain nuclei to effect coordinated control of so many visceral structures. In a recent review of the central connections of the vagus nerve, Sawchenko recognized four levels of organization of the outputs from the nucleus tractus solitarius and area postrema. The dorsal motor nucleus and the nucleus ambiguus have broadly similar central connections and in general, regions which receive an input from the vagal sensory nuclei project back to both the motor nuclei. An initial flurry of research activity yielded a large amount of fresh information in a relatively short time.
