Hierarchical cortical control of neuroimmunomodulatory pathways.

The central nervous system and the immune system are both stimulus response systems with sophisticated memories mediating defence and adaptation to external and internal threats. There is mounting evidence that these two systems share their information in a bidirectional flow of cytokines, steroids, and neuropeptides. This review examines the influence of higher cognitive centres on immunity and highlights the central role played by the hypothalamus in enabling these two systems to function as an integrated unit to maintain homeostasis. The search for novel compounds that are capable of enhancing immunity by regulating these brain-immune feedback loops offers one of the most exciting areas for future neurobiological research.