【摘要】 目的:观察有氧运动对D-半乳糖诱导的脑衰老过程中大鼠学习记忆及海马PSD-95表达的影响,探讨有氧运动延缓脑衰老过程中学习记忆能力下降的潜在机制。方法:30只SD雄性大鼠随机分成对照组(Y组)、衰老模型组(D组)和衰老过程中运动组(DS组),每组10只。每日给予D组、DS组大鼠1次D-半乳糖(100mg/kg/d)腹腔注射,持续6周;同期,DS组大鼠每日进行1次1h/d)有氧游泳运动。6周后,利用Morris水迷宫评估大鼠学习与记忆能力;再采用Real Time-PCR、Western Blot、免疫荧光分别检测海马组织PSD-95mRNA和PSD-95蛋白表达。结果:在水迷宫定位航行训练中,3组大鼠平均逃避潜伏期、逃避路程在训练开始时无显著性差异,从第3天开始至结束,D组平均逃避潜伏期、逃避路程均显著性长于Y组(P<0.05),DS组则比D组显著缩短(P<0.05);在空间探索实验中,D组在原有平台所在区域进行搜索的时间显著性少于Y组(P<0.01),DS组则比D组显著性增加(P<0.01)。D组大鼠海马组织PSD-95mRNA和PSD-95蛋白的表达水平均显著性低于Y组(P<0.05;P<0.01),DS组表达水平则明显高于D组大鼠(P<0.05;P<0.01)。结论:有氧游泳运动干预可以延缓D-半乳糖诱导的脑衰老过程中大鼠学习记忆能力的下降,而促进海马PSD-95蛋白表达水平上调可能是其神经机制之一。更多还原

【Abstract】 This study aimed to study the effect of aerobic exercise on expression of PSD-95 in hippocampus of brain aging rats induced by D-galactose and to illustrate the mechanisms underlying that aerobic exercise attenuate the declining of learning and memory abilities in brain aging process.30 healthy male Sprague-Dawley rats(weight 390-430g)were divided randomly into 3groups:young control group(group Y,N=10),the aging model group(group D,N=10)and the aerobic exercise group(group DS,N=10),The rats in both group D and group DS had been injected D- galactose(100mg/kg/d)into the abdominal cavity daily for 6weeks.At the same time,the rats in group DS had performed aerobic swimming for 1hour daily.Subsequently,the Morris Water Maze(MWM)was used to assess rats’ learning?and?memory abilities,and the real time PCR,western blotting technologies and immunofluorescenc were applied to detect the expression of PSD-95 mRNA and PSD-95 protein in rats’ hippocampi?respectively.In MWM’ navigation training,the mean escape latency and the path length of every rats in three groups were gradually shorting with training times increase,but since the third day of training,those of group Y were longer obviously than group Y and DS(P<0.05).In MWM’ space explore test,rats in both group Y and DS had longer time in 60 seconds to stay in the original plat-form quadrant than group D(P<0.01,P<0.01).The expression levels of PSD-95 mRNA and PSD-95 protein in rats’ hippocampi in group D were significantly lower than group Y(P<0.01;P<0.05),while compared to group D,the levels of PSD-95 mRNA and PSD-95 protein were apparently increased(P<0.05;P<0.01).These results suggest that aerobic exercise might attenuate the decline of learning and memory abilities of brain aging rat induced by D-galactose.Promoting transcription and translation of PSD-95 gene in hippocampi’ neurons to make expression levels of PSD-95 protein in hippocampus increase might be one of the neural mechanisms underlying that aerobic exercise attenuate the decline of learning and memory abilities during aging brain.更多还原