Abstract: AIM: To investigate the changes of neuroapoptosis in brain and learning ability after neonatal mice exposed to inhaled sevoflurane or isoflurane.METHODS: Ninety postnatal day(P)7 Wistar rats were randomly divided into 5 groups : group A sham anesthesia,group B 3.6% sevoflurane for 2 h, group C 3.6% sevoflurane for 6 h, group D 2.3% isoflurane for 2 h and group E 2.3% isoflurane for 6 h. Animals from each group were perfused transcardially with 0.1 mol phosphate buffer containing 4% paraformaldehyde 6 h after the end of anesthesia, and then the brains were exposed for immunohisochemistry, caspase-3 positive cells were detected. Behavioral studies with Morris water maze test were performed separately when the rats were 5-week-old and 14-week-old.RESULTS: The amounts of caspase-3 positive cells in the rats brain of Group B, C,D and E were greater than that in Group A, and the amount in group C was greater than that in gourp B, in group E more than that in group B(P<0.05). When face the spatial reference memory task or space exploration task, rats from different groups make it uniformly. Anesthetic rats and control rats performed similarly in terms of path length when learning to swim to the platform during locating trials. No rats showed significantly higher levels of retention during the probe trials in terms of target quadrant time, platform crossings and platform location time(P>0.05),but the number of platform crossings in group B,C,D and E was significantly higher than that in gourp A(P<0.05).CONCLUSION: Exposure to the concentration of 3.6% sevoflurane or 2.3% isoflurane could cause brain cell apoptosis of newborn rats. Isoflurane could cause more insults to brain than sevoflurane at an equivalent concentration. The memory ability to pessimal stimulation is decreased as the anesthesia mice 5 weeks old, such changes recede along with the growth of rats. Exposure to sevoflurane and isoflurane does not affect the spatial reference memory of newborn rat during their growth.

Key words: Sevoflurane, Isoflurane, Newborn rats, caspase-3, Spatial reference memory