摘要
目的研究慢性低压低氧环境暴露对大鼠学习记忆能力的影响,以及神经元形态学和凋亡水平的变化。方法选择雄性SD大鼠60只,根据不同海拔自然环境随机分为高海拔组(青海省玛多县4300 m)、中海拔组(青海省西宁市2260 m)、平原组(陕西省西安市450 m),每组20只。连续饲养8周,Morris水迷宫实验比较3组大鼠空间学习记忆能力。行为学实验结束后,制作脑切片,行苏木精-尹红染色、Nissl染色,观察神经元形态学变化特征;TUNEL染色观察凋亡神经元;电镜观察神经元超微结构;免疫荧光双标检测神经元特异核蛋白(Neun)抗体和半胱氨酸天冬氨酸蛋白酶3(Caspase-3)表达。结果高海拔组开始训练第3、4天平均逃避潜伏期较中海拔组和平原组明显延长,穿越平台次数、穿越目标象限时间百分比比较中海拔组和平原组明显减少[(0.53±0.21)次vs(0.95±0.50)次、(1.00±0.63)次,(29.12±10.58)%vs(35.18±12.45)%、(37.74±9.13)%,P<0.05]。与中海拔组和平原组比较,高海拔组尼氏小体明显减少(P<0.05,P<0.01)。与平原组比较,中海拔组和高海拔组海马细胞凋亡率明显升高,高海拔组皮质细胞凋亡率明显升高(P<0.05,P<0.01);与中海拔组比较,高海拔组海马和皮质细胞凋亡率明显升高(P<0.01)。免疫荧光双染可见,与平原组比较,高海拔组海马和皮质Caspase-3表达明显升高,海马Neun表达明显降低(P<0.05)。结论高海拔慢性低压低氧环境暴露可导致大鼠认知功能损害。
Objective To study the effect of chronic exposure to hypobaric hypoxia on learning,memory,neuronal morphology and apoptosis.Methods Sixty male SD rats were randomly divided into high altitude group,medium altitude group,plain group(20 in each group).The animals in different groups were bred for 8 weeks.Their learning and memory were compared in Morris water maze experiment.The brain tissue sections were prepared after behavioral experiment to observe the morphology of neurons with HE staining and Nissl staining.The apoptosis of neurons was assyed with TUNEL staining.The ultrastructure of neurons was detected by electron microscopy.The expressions of neuron-specific nuclear protein antibody and Caspase-3 were detected with immunofluoresce double staining.Results The average escape incubation period was significantly longer in high altitude group than in medium altitude group and plain group on days 3 and 4 after training(P<0.05)while the number of crossing platform was significantly smaller and the ratio of crossing target quadrant was significantly lower in high altitude group than in medium altitude group and plain group on days 3 and 4 after training(0.53±0.21 vs 0.95±0.50,1.00±0.63,29.12%±10.58%vs 35.18%±12.45%,37.74%±9.13%,P<0.05).The number of Nissl bodies was significantly smaller in high altitude group than in medium altitude group and plain group(P<0.05,P<0.01).The apoptosis rate of hippocampal cells was significantly higher in medium altitude group and high altitude group than in plain group,that of cortical cells was significantly higher in high altitude group than in plain group(P<0.05,P<0.01)and that of hippocampal and cortical cells was significantly higher in high altitude group than in medium altitude group(P<0.01).Immunofluo rescence double staining showed that the expression level of Caspase-3 was significantly higher while that of neuron-specific nuclear protein antibody was significantly lower in high altitude group than in plain group(P<0.05).Conclusion Chronic exposure to hypobaric hypoxia can lead to cognitive impairment in rats.
作者
吉维忠
张亚清
格日力
Ji Weizhong;Zhang Yaqing;Ge Rili(Research Center for High Altitude Medicine,Qinghai University,Xining 810001,Qinghai Province,China)
出处
《中华老年心脑血管病杂志》
北大核心
2021年第3期301-305,共5页
Chinese Journal of Geriatric Heart,Brain and Vessel Diseases
基金
青海省科技计划项目(2020-ZJ-757)。
