Many studies have demonstrated that ablation of the sympathetic nervous
system (SNS) alters subsequent immune responses. Researchers have
presumed 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 nervous
system (CNS). Activation of the CNS was determined by
immunocytochemical visualization of Fos protein in brains from male
C57BL/6 mice at 8, 24, and 48 h following denervation. A dramatic
induction of Fos protein was found in the paraventricular nucleus (PVN) of
the hypothalamus 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 hydroxylase, and adrenocorticotropin, do not coexpress Fos. Our
findings suggest an involvement of the CNS in sympathectomy-induced
alterations of immunity.
Central Nervous System Activation following Peripheral Chemical Sympathectomy: Implications for Neural–Immune Interactions
Brain, Behavior, and Immunity
Volume 12, Issue 3, September 1998, Pages 230-241