EFFECTS OF SEVOFLURANE AND ISOFLURANE ANAESTHESIA ON LONG-TERM COGNITIVE FUNCTION AND HIPPOCAMPAL INFLAMMATORY RESPONSE IN NEONATAL MICE

Objective: To investigate the effects of sevoflurane and isoflurane anaesthesia on long- term cognitive function and hippocampal inflammatory response in neonatal mice. Methods: A total of 57 healthy SD mice were randomly divided into three groups: a control group, an isoflurane group, and a sevoflurane group, with 19 mice in each group. Control group mice inhaled normal air, while mice in the isoflurane group inhaled 2% isoflurane, mice in the sevoflurane group inhaled 2% sevoflurane, mice in the isoflurane group and sevoflurane group inhaled air with an oxygen concentration of 30%, and the three groups of mice inhaled gas for five hours. The levels of hippocampal inflammatory factors (interleukin-1beta [IL-1beta], interleukin-6 [IL-6], tumour necrosis factor- alpha [TNF-alpha]) and the indexes of the Morris water maze test (escape latency time, exploration time of plateau area and times of crossing the original plateau, residence time in central area, residence time in peripheral area, average velocity) were observed in each group. DNF and Syn-1 levels were also measured. Results: The levels of IL-1beta and TNF- alpha in the sevoflurane group and the isoflurane group were significantly higher than those in the control group (P<0.05). The levels of IL-6 in the sevoflurane group and the isoflurane group were higher than those in the control group, but there was no significant difference (P>0.05). Compared with the control group, the escape latency time of mice in the sevoflurane group and the isoflurane group increased significantly, and the exploration time of platform area and the times of crossing the original platform decreased significantly (P<0.05), but there was no significant difference between the sevoflurane group and the isoflurane group in escape latency, platform area exploration time and the time taken crossing the original platform (P>0.05). Compared with the control group, the central and peripheral residence time of the sevoflurane group and the isoflurane group decreased significantly, and the difference was statistically significant (P<0.05). The average speed of mice in each group had no significant difference (P>0.05). Compared with the control group, the levels of brain-derived neurotrophic factor (BDNF) and Syn-1 in the sevoflurane group and the isoflurane group were significantly lower (P<0.05), but the levels of BDNF and Syn-1 in the sevoflurane group and the isoflurane group were not significantly different (P>0.05). Conclusion: Sevoflurane and isoflurane anaesthesia can impair the long- term cognitive function of neonatal mice and promote an inflammatory response in the hippocampus.