Figure 1.

Schematic representation of the neuroanatomical connections between the gastrointestinal (GI) tract and brainstem vagal nuclei involved in the regulation of food intake. Sensory information from the GI tract is relayed centrally via the afferent vagus which responds both directly (via neuropods) and indirectly (via paracrine signaling) to gastrointestinal stimulation. At the level of the dorsal hindbrain, afferent vagal inputs enter the brainstem via the tractus solitarius (TS) and terminate on neurons of the nucleus of the tractus solitarius (NTS). The integrated signal is relayed from the NTS to the adjacent dorsal motor nucleus of the vagus (DMV) via catecholaminergic, glutamatergic, and predominantly gamma aminobutyric acid (GABA)-ergic, synapses. The DMV contains preganglionic parasympathetic motoneurons that relayed the resulting output signal to the GI tract via the efferent motor vagus. EEC—enteroendocrine cells; CC—central canal.