摘要目的 探讨模拟单一与复合航天特因环境下大鼠在Morrs水迷宫(Morris water maze,MWM)实验中的学习记忆能力差异,为建立航天特因环境下稳定的认知功能障碍动物模型提供参考.方法 48只SD大鼠采用随机数字表法分为假尾吊组(Sham)、尾吊组(tail suspension,TS)、尾吊复合隔离组(tail suspension+isolation,TS+I),每组16只.造模2周、4周后每组取8只分别依次进行定位航行实验(5d)、空间搜索实验(1 d)和工作记忆实验(3 d)检测其学习记忆能力.假尾吊组作为对照.结果 在定航实验中,2周后复合组的潜伏期最长[(59.63±3.55)s],其次是尾吊组[(38.02±3.21)s],假尾吊组潜伏期最短[(20.85±3.22)s].各组之间比较差异有统计学意义(P＜0.05,P＜0.01).4周后的结果与2周类似.空间探索实验中,2周后复合组的实台象限时间比最少(0.29±0.04),其次是尾吊组(0.38±0.03),假尾吊组的实台象限时间比最多(0.42±0.03),各组之间比较差异有统计学意义(P＜0.05,P＜0.01).工作记忆实验中,2周后假尾吊组大鼠的潜伏期最短[(23.05±7.39)s],其次是尾吊组[(41.01±6.74)s],复合组大鼠潜伏期最长[(60.05±11.61)s],各组之间比较差异有统计学意义(P＜0.05,P＜0.01).4周后的结果类似于2周(P＜0.05,P＜0.01).结论 模拟复合航天特因环境较单一尾吊对大鼠认知功能损伤更为严重.

abstractsObjective To investigate the learning and memory abilities of rats in the Morris water maze (MWM) test under the different simulated environment of space flight.Methods Forty-eight SD rats were randomly divided into Sham group,TS group and TS+I group,with sixteen animals in each group.Place navigation,spatial probe and working memory tests were performed to determine the learning and memory abilities for each group after 2 weeks and 4 weeks respectively.The Sham group served as controls.Results In the place navigation test after simulated 2 weeks,the latency was the longest ((59.63 ± 3.55) s) in the rats of TS + I group,shorter ((38.02±3.21) s) in the TS group,the shortest ((20.85±3.22) s) in the Sham group.Results after simulated 4 weeks were similar to the results after simulated 2 weeks to rats.In the spatial probe test in the MWM test after simulated 2 weeks,the ratio of time spent in target quadrant was the least (0.29±0.04) in the rats in the TS+I group,more (0.38±0.03) in the TS group,and the most (0.42±0.03) in the TS+I group.In the working memory test in the MWM test,after simulated 2 weeks,compared with the Sham group ((23.05±7.39)s),the latency was longer in the TS group ((41.01±6.74)s) and TS+I group ((60.05±11.61)s).All these differences were significant (P＜0.05,P＜0.01).Conclusion More serious cognitive impairment will occur in the tail suspension plus isolation rather than the single tail suspension in rats.