Effects of isoflurane anesthesia on inflammatory responses and long-term cognitive function in hippocampi of neonatal rats

Objective To evaluate the effects of isoflurane anesthesia on inflammatory responses and long-term cognitive function in the hippocampi of neonatal rats .Methods Forty-six Sprague-Dawley rats of both sexes , aged 7 days ,weighing 12-17 g ,were randomly divided into 2 groups （n=23 each）：control group （group C） and isoflurane anesthesia group （group I ） .In group I ,the rats were exposed to 2.5% isoflurane for 3 min to induce anesthesia and then exposed to 1.5% isoflurane for 4 h to maintain anesthesia ,while in group C the rats were only exposed to air for 4 h .Eight rats in each group were sacrificed and hippocampi were removed for determination of the levels of interleukin-6 ,interleukin-1βand tumor necrosis factor-α.Open field and Morris water maze tests were carried out three weeks later in the left rats .Results Compared with group C ,the escape latency was significantly prolonged ,the time of staying at the central region was shortened ,the time of staying at the border region was prolonged ,the total distance was reduced , and the contents of interleukin-1β and tumor necrosis factor-αwere increased in group I （ P〈0.05） .Conclusion Isoflurane anesthesia results in decreased cognitive function ,which may be related to promotion of inflammatory responses in the hippocampi of neonatal rats . Key words: Isoflurane; Infant,newborn; Cognition disorders; Hippocampus; Inflammation