跑台运动对抑郁模型大鼠学习记忆及海马CA1区BDNF表达的影响

目的：观察4周跑台运动对慢性应激致抑郁大鼠空间学习记忆能力,血浆皮质醇（Cortisol,cort）含量和海马CA1区脑源性神经营养因子（Brain Derived Neurotrophic Factor,BDNF）表达的影响.方法：30只SD大鼠随机分为正常对照组、应激模型组及应激运动组,制作慢性不可预见性应激模型,用八臂迷宫实验观察各组大鼠学习记忆等行为学指标的变化,放射免疫法测试大鼠血浆cort含量,免疫组织化学结合图像半定量方法对海马CA1区BDNF神经元的数量及面积进行测量和分析.结果：慢性应激致抑郁大鼠血浆cort含量增加,八臂迷宫实验中应激大鼠完成八臂迷宫时间显著延长,工作记忆错误次数、参考记忆错误次数及总记忆错误次数均显著增加,海马CA1区BDNF表达减弱.而长期跑台运动可以显著改善抑郁模型大鼠的学习记忆能力,血浆cort含量降低,海马CA1区BDNF表达增强.结论：跑台运动可改善抑郁模型大鼠的学习记忆能力,机理可能与长期运动降低抑郁大鼠的血浆cort水平、拮抗HPA轴功能亢进及增强海马CA1区BDNF的表达有关.

Effects of Treadmill Exercise on the Learning and Memory of Depressed Rats and Their BDNF Expression within Hippocampus CA1

Objetive：To explore the effects of a 4 - weektreadmill exercise on depressed rats＇ learning and memoryand blood plasma cort content,and their BDNF expressionwithin Hippocampus CA1. The depression was induced by Chronic Unpredictable Stress（CUMS）. Methods：30 male SDrats were randomly allocated to 3 groups,control group（C）,stress model group（SM） and stress exercise group（SE）. Allrats except those of Group C were exposed to a chronic un-predictable stress（CUMS）. The learning and memory abilityof the rats were tested with an eight-arm radial maze test,thecort content was tested by radioimmunoassay and BDNF ex-pression within Hippocampus CA1 was detected and analy-sised by using ABC immunohistochemical technique andsemiquan-titative. Results：Compared with Group C,the bloodplasma cort content increased in the SM group,the time forcompleting 8 -arms radial maze shortened and WME（work-ing memory error）,RME（reference memory error） and TE（total memory error） significantly increased in eight-arm ra-dial maze test,BDNF expression within Hippocampus CA1decreased in the SM group rats compared with Group C. Theresults showed that treadmill exercise significantly improvedlearning and memory of the depressed rats,that the bloodplasma cort content decreased and that BDNF expression en-hanced within Hippocampus CA1 in the SE group rats. Con-clusion：The treadmill exercise may enhance the learning andmemory ability of depressed rats,the mechanism of whichmight be that treadmill exercise decreases the blood plasmacort content,overactive HPA axis antagonism and reducesthe BDNF expression within Hippocampus CA1.