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

Abstract

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-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNFα) 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-1β 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 TNFα 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 TNFα. 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 TNFα caused by LPS and may be a viable alternative to antibiotics.