The Nucleus of the Solitary Tract: Processing Information from Viscerosensory Afferents

The nucleus of the solitary tract (NTS) is the first location within the central nervous system for the integration and modulation of cardiovascular afferent as well as other viscerosensory input. The NTS is therefore a pivotal structure for maintaining homeostasis. This chapter examines the fundamental cellular and molecular building blocks of NTS pathways. It discusses NTS neurotransmitters, (glutamate and ϒ-amino-butyric acid, GABA) and the baroreceptor reflex, the mechanisms regulating afferent information transfer to sites beyond the NTS and the mechanisms by which two major modulators, angiotensin II and nitric oxide, transform afferent information related to cardiovascular regulation. Particular consideration is given to emerging views on the nature and role of heterogeneity in afferents and NTS neurons and their projection targets outside the NTS. The chapter also considers the impact of new signaling molecules in the endothelial interface between the bloodstream and brain on neural control of the circulation.