Role of neurons in the control of immune defense.

Studies in recent years have strengthened the notion that neural mechanisms are involved in the control of immune responses. From initial studies that highlighted the vagus nerve control of inflammatory responses in vertebrates, many advances have been made, including the dissection of specific neural circuits that are involved in controlling immunity. Part of this has been facilitated by the use of a tractable model animal, Caenorhabditis elegans, in which individual neurons involved in sensing pathogens and controlling the immune response have been identified. Importantly, some of the underlying mechanisms involved in the neural control of immune pathways appear to be present in evolutionarily diverse species. This review focuses on some major developments in vertebrates and C. elegans, and how these discoveries may lead to advances in understanding neural-immune connections that govern inflammatory responses.