CENTRAL NERVOUS SYSTEM-IMMUNE SYSTEM INTERACTIONS - PSYCHONEUROENDOCRINOLOGY OF STRESS AND ITS IMMUNE CONSEQUENCES

Psychoneuroimmunology is a relatively new discipline which deals with CNS-immune system interactions. The evidence for such interactions was reviewed, as was the neuroendocrinologic response to stress. Recent e vidence indicates that the behavioral, nervous system, and neuroendocr ine responses to stress are mediated by hypothalamic CRF, which acts o n both the sympathetic nervous system and the HPA axis, resulting in i ncreased levels of corticosteroids, catecholamines, and certain opiate s, substances which are generally immunosuppressive. Concentrations of growth hormone and prolactin, which are immunoenhancing, are elevated early during the response to stress but are later suppressed. Althoug h several other neuromediators may also be released with stress, the n et effect of a variety of acute stressors is down regulation of the im mune system function. In the following minireview, I consider whether stress alters the resistance of the host to infection as well as the i mmunomodulatory effects of released immune system mediators on the bra in (6).