The effects of sevoflurane anesthesia on rat hippocampus: a genomic expression analysis

Recent studies have shown that general anesthesia induces memory impairment. Sevoflurane, an inhalation anesthetic, is widely used in clinical practice, increasing pieces of evidence suggest that sevoflurane impairs memory processes due to changing gene expression in hippocampus. However, little is known about genome-widely analyzing the expression change induced by sevoflurane in hippocampus. In this study, we profiled the changes of hippocampal gene expression by microarray analysis. Six-week-old male Sprague-Dawley rats were anesthetized for 4h with 2.5% sevoflurane (n = 6) and were sacrificed 48 h later. RNA was extracted from the hippocampus for gene expression profile. Compared to control group, 417 genes, including up-regulated 67 and down-regulated 350, were significantly changed (> 2.0 or < -2.0 fold) (P < 0.05). Of these, there are 45 named genes, which are most involved in metabolism, development, biosynthesis, life material binding, location, signal transduction and communication, structural and vesicular processes. We randomly chose 6 differential genes to verify the microarray result. We also selected seven most differential genes, including 3 up-regulated genes (RMCP-1, Slc6a3, and Pitx2) and 4 down-regulated genes (VN7, AVP, IP10, and OT), to investigate whether there is a dose- or time-dependent effect of sevoflurane on gene expression. The result indicated that the microarray profile is reliable; there is no obvious dose-dependent effect of sevoflurane on gene expression. These results suggested that sevoflurane induced long-term (at least 2 days) expression change of the numerous genes in hippocampus, which may be related to the memory impairment or the other neural disorders.