The duration-dependent and sex-specific effects of neonatal sevofiurane exposure on cognitive function in rats

Clinical studies have found that neonatal sevofiurane exposure can increase the risk of cognitive dysfunction. However, recent studies have found that it can exhibit neuroprotective effects in some situations. In this study, we aimed to explore the effects of sevofiurane neonatal exposure in rats. A total of 144 rat pups (72 males and 72 females) were assigned to six groups and separately according to sevofiurane exposure of different times on the seventh day after birth. Blood gas analysis and western blot detection in the hippocampus were conducted after exposure. The Morris water maze test was conducted on the 32nd to 38th days after birth. The expression of PSD95 and synaptophysin in the hippocampus was detected after the Morris water maze test. We found that neonatal exposure to sevofiurane promoted apoptosis in the hippocampus, and Bax and caspase-3 were increased in a dose-dependent manner. The 2-h exposure had the greatest effects on cognitive dysfunction. However, with the extension of exposure time to 6 h, the effects on cognitive function were partly compensated. In addition, sevofiurane exposure decreased synaptogenesis in the hippocampus. However, as the exposure time was extended, the suppression of synaptogenesis was attenuated. In conclusion, neonatal sevofiurane exposure exhibited duration-dependent effects on cognitive function via Bax-caspase-3-dependent apoptosis and bidirectional effects on synaptogenesis in rats.