The Long-term Effects Of Sevoflurane Given By Different Concentration And Time Course On Cognitive Function In Neonate Rats And Its Possible Mechanisms

Objective to investigate the long-term effects of sevoflurane given by different concentration and time course on cognitive function and expressions of BDNF,ERK and Fos in the hippocampus of ratsMethods 80 SD rats,seven-day-old, were randomly divided into 4 groups:Ⅰonly inhaled 60%O2(group C);group II,groupⅢand groupⅢinhaled sevoflurane at 5.1% ,for 1.3 h(group S)at 3.4% for 2 h(group M)and at 1.7% for 4 h(group L).Open field test ,novel obiect recognition test ,water maze were used to assess the cognitive function of the rats at 28-day-old。The animals were killed after the tests and measurede the expressions of BDNF , p-ERK and Fos using immuno-histochemistry , BDNFmRNA, ERK1mRNA and ERK2mRNA usingreverse transcriptive polymerase chain reaction in hippocampus respectively. Results No matter the tests of cognitive function or expressions of BDNF, ERK and Fos in hippocampus,there was no significant change between S group and C group。Group M didn't not exhibit significant difference in comparison with group control in every item of the open field test.Compared to the controls,in the novel obiect recognition test, M group showed significantly more time to explore novel obiect in 24 h hour.In water maze,group M showed more times the rats going into the dead end than the controls.we found the number of pyramidal cells decreased in hippocampus ,but which had no sense in statistics. The expressions of BDNF,p-ERK and Fos in hippocampus were all significantly lower in group M than in control C. In all tests,each index of group L was worse than group C。Conclusion sevoflurane can induce forward cognitive decline in neonate rat。The time of inhaleing sevoflurane longer,the more serious cognitive dyfunction made,that may be because of decreasing the expression of BDNF , ERK and Fos in hippocampus.