Vagal nerve stimulation attenuates IL-6 and TNFα expression in respiratory regions of the developing rat brainstem

Pre-term infants are at greater risk for systemic infection due to an underdeveloped immune system. Airway infection results in immune up-regulation of early pro-inflammatory cytokines interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF alpha) in the brainstem. Current treatment for neonatal infection involves antibiotic administration. We previously showed that LPS injected into the trachea of neonatal rats causes changes in breathing and in IL-1 beta expression in the nucleus tractus solitarii (NTS) and hypoglossal motor nucleus (XII). We hypothesize that lipopolysaccharide (LPS) instilled in the trachea also causes the up-regulation of IL-6 and TNF alpha in the brainstem autonomic control regions. To test this hypothesis we injected LPS into the trachea of rat pups (postnatal ages 10-12 days) and then assessed changes in IL-6 and TNF alpha. Vagal nerve stimulation has been used in the treatment of many inflammatory disorders, including sepsis. Our experiments show that VNS attenuates the upregulation of IL-6 and TNF alpha caused by LPS and may be a viable alternative to antibiotics. (C) 2016 Published by Elsevier B.V.