Figure 1.

Parasympathetic and sympathetic nervous systems regulate inflammation of internal organs. Sympathetic and parasympathetic systems innervate almost all internal organs. Current studies have confirmed that the vagus nerve can sense inflammatory signals and transmit them to the Nucleus Tractus Solitarius (NTS) of the Medullary Visceral Zone (MVZ). In MVZ, NTS links to the Rostral Ventrolateral Medulla (RVLM) and Vagus Dorsal Motor Nucleus (VDMN) to process the incoming information. On the other hand, MVZ connects the hypothalamus, basal forebrain (BF), and forebrain upwards and connects the locus coeruleus downwards so that the sympathetic and vagus systems, the autonomic nervous system, and the neuroendocrine regulation system can cooperate to regulate inflammation and immunity. (a) The regulation of Cholinergic Anti-inflammatory Pathways (CAP) on systemic inflammation. After the efferent vagus fibers from the Vagus Dorsal Motor Nucleus (VDMN) shift neurons in the upper abdominal cavity mesenteric ganglion complex, their postganglionic fibers enter the spleen and release norepinephrine which acts on the T lymphocytes to facilitate synthesizing ACh, and the latter activate α7nAChRs on the monocytes to inhibit releasing proinflammatory cytokines. (b) The central regulation pathway of the cholinergic system. After the inflammatory information from NTS is modified by BF, the postganglionic fibers of BF release ACh which bind to the M1AChRs on the cholinergic neuron of the forebrain to regulate the systemic inflammation and immunity through MVZ.