1. Department of Anesthesiology, the Fourth Medical Center of Chinese PLA General Hospital, Beijing 100048, China; 2. Trauma Repairment and Tissue Regeneration Center, Department of Medical Innovation Study, Chinese PLA General Hospital, Beijing 100053, China; 3. Department of Gynecology and Obstetrics, the Sixth Medical Center of Chinese PLA General Hospital, Beijing 100142, China
Abstract：Objective To investigate the effects of physical activity on spatial cognition and molecular mechanism of postnatal isoflurane exposure in rats of different genders. Methods A total of 110 SD rats were randomly divided into four groups at postnatal 7 days (7 d): group Naive(n=28), Naive+PA(n=30), Iso(n=26) and Iso+PA(n=26). Iso and Iso+PA were exposed to isoflurane for 2 hours in P7, P9 and P11. The rats were separated by genders at 21st day after birth. For groups of Naive+PA and Iso+PA, physical activity was conducted. After 6 weeks, behavioral tests were conducted including radial maze (RAM) and Morris water maze (MWM). After those tests, brain of adult rats was harvested and used to examine the expression of BDNF, Ki-67 by immunohistochemistry and Western blot. Results The total time of each group during the training phase of RAM showed a significant decline with training; compared with group Iso, the performance of adult rats in group Naive was significantly more stable; there was significantly different in PA groups versus non-PA ones. Compared with group Naive, reference memory errors and total time increased in the Iso group, especially in female rats (P<0.05); the reference memory errors of Naive+PA group were significantly less than those of non-PA males (P<0.05); the total time in the PA males was also reduced with a significant difference (group Naive versus Iso in males: P<0.05); Compared with Iso male group, the total time of group Iso+PA became lower significantly (P<0.05). In the water maze test, the duration of target quadrant was significantly reduced in group Iso of females (P<0.05). Compared with group Naive, expressions of BDNF and Ki-67 in the hippocampus of Iso significantly decreased, and expression of Ki-67 increased in the PA male group. Compared with Iso, expression of BDNF in Iso+PA group were higher than group Iso,particularly in females (P<0.05). Conclusions Repeated isoflurane exposure has certain effect on spatial cognition. Spatial memory impairment in males is manifested in long-term memory (reference memory), while females are in short-term memory (working memory). It is also found that physical activity can enhance learning ability and spatial cognitive function,particularly in males.
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2022, Vol. 33 
