CENTRAL-NERVOUS-SYSTEM ACTIVATION FOLLOWING PERIPHERAL CHEMICAL SYMPATHECTOMY - IMPLICATIONS FOR NEURAL-IMMUNE INTERACTIONS

Many studies have demonstrated that ablation of the sympathetic nervou s system (SNS) alters subsequent immune responses. Researchers have pr esumed that the altered immune responses are predominantly the result of the peripheral phenomenon of denervation. We, however, hypothesized that chemical sympathectomy will signal and activate the central nerv ous system (CNS). Activation of the CNS was determined by immunocytoch emical visualization of Fos protein in brains from male C57BL/6 mice a t 8, 24, and 48 h following denervation. A dramatic induction of Fos p rotein was found in the paraventricular nucleus (PVN) of the hypothala mus and other specific brain regions at 8 and 24 h compared to vehicle control mice. Dual-antigen labeling demonstrates that corticotrophin releasing factor (CRF)-containing neurons in the PVN are activated by chemical sympathectomy; however, neurons containing neurotransmitters which may modulate CRF neurons, such as vasopressin, tyrosine hydroxyl ase, and adrenocorticotropin, do not coexpress Fos. Our findings sugge st an involvement of the CNS in sympathectomy-induced alterations of i mmunity. (C) 1998 Academic Press.