Role for the cervical sympathetic trunk in regulating anaphylactic and endotoxic shock

This study tests the hypothesis that spinal nerves projecting down the cervical sympathetic trunk contribute to the regulation of systemic immune responses. Decentralization or ablation (ganglionectomy) of the superior cervical ganglia (SCG), which receive innervation from spinal segments C8-T8, were found to reduce the pulmonary inflammatory response consequent to induction of anaphylaxis in rats sensitized to the nematode Nippostrongylus brasiliensis. Furthermore, the hypotensive responses to IV endotoxin were attenuated in sensitized rats by these operations, whereas decentralization without ganglionectomy protected against endotoxic shock in normal (unsensitized) rats. These results suggest that systemic inflammatory events are regulated by the cervical sympathetic nervous system at a level superior to the superior cervical ganglia. Further studies are warranted to investigate the role of the cervical and thoracic sympathetic nerves in the regulation of systemic immunological function.