Vagal immune-to-brain communication: a visceral chemosensory pathway

• Published in: Autonomic Neuroscience: Basic and Clinical Vol. 85; no. 1; pp. 49 - 59
• Main Authors: Goehler, Lisa E., Gaykema, Ron P.A., Hansen, Michael K., Anderson, Karl, Maier, Steven F., Watkins, Linda R.
• Format: Book Review Conference Proceeding Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 20.12.2000; Elsevier
• Subjects: Acute phase; Animals; Biological and medical sciences; Brain - cytology; Brain - immunology; Chemoreceptor Cells - immunology; Cytokines; Fundamental and applied biological sciences. Psychology; Immunosensory; Neuroimmunomodulation - physiology; Neurons, Afferent - immunology; Primary afferents; Thermoregulation. Hibernation. Estivation. Ecophysiology and environmental effects; Vagus; Vagus Nerve - cytology; Vagus Nerve - immunology; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Primary afferents; Vagus; Cytokines; Acute phase; Immunosensory; Autonomic nervous system; Central nervous system; Cytokine; Chemosensitivity; Review; Vagus nerve; Parasympathetic nervous system; Chemoreceptor; Brain (vertebrata); Immune system
• ISSN: 1566-0702; 1872-7484
• DOI: 10.1016/S1566-0702(00)00219-8

The immune system operates as a diffuse sensory system, detecting the presence of specific chemical constituents associated with dangerous micro-organisms, and then signalling the brain. In this way, immunosensation constitutes a chemosensory system. Several submodalities of this sensory system function as pathways conveying immune-related information, and can be classified as either primarily brain barrier associated or neural. The vagus nerve provides the major neural pathway identified to date. The initial chemosensory transduction events occur in immune cells, which respond to specific chemical components expressed by dangerous micro-organisms. These immune chemosensory cells release mediators, such as cytokines, to activate neural elements, including primary afferent neurons of the vagal sensory ganglia. Primary afferent activation initiates local reflexes (e.g. cardiovascular and gastrointestinal) that support host defense. In addition, at least three parallel pathways of ascending immune-related information activate specific components of the illness response. In this way, immunosensory systems represent highly organized and coherent pathways for activating host defense against infection.