自愿转轮运动对抑郁模型大鼠学习记忆能力及海马齿状回一氧化氮合酶表达的影响

目的：观察4周自愿转轮运动对慢性应激致抑郁大鼠绝望行为及空间学习记忆能力和海马DG区nNOS表达的影响.方法：30只SD大鼠随机分为对照组、应激模型组及应激运动组,应激模型组及应激运动组大鼠建立慢性不可预见性应激（chronic unpredictable mild stress,CUMS）抑郁模型,同时应激运动组大鼠进行4周自愿转轮运动.运动及应激结束后通过强迫游泳实验及八臂迷宫实验等方法测试大鼠行为学指标变化,免疫组织化学法检测大鼠海马DG区nNOS神经元的表达.结果：（1）与对照组相比,慢性应激致抑郁大鼠强迫游泳实验中大鼠不动时间延长,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DG区nNOS表达显著增强.（2）与应激模型组比较,应激运动组大鼠强迫游泳实验中大鼠不动时间缩短,八臂迷宫实验中应激运动组大鼠完成八臂迷宫时间显著缩短,参考记忆错误次数及总记忆错误次数均显著减少,海马DG区nNOS表达减弱.结论：自愿转轮运动可改善抑郁模型大鼠的绝望行为、提高大鼠学习记忆能力,机理可能与长期自愿转轮运动减弱抑郁大鼠海马DG区nNOS表达导致NO神经毒性减弱有关.

Effects of Voluntary Wheeling Exercise on Learning and Memory and nNOS Expression within Hippocampus DG in the Depressive Model Rats

Objective：To explore the effects of the 4 - weekvoluntary wheeling exercise on the despair behavior andlearning and memory and nNOS expression within Hippo-campus DG in the depressive model rats induced by Chro-nic 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）. All rats except the C group are exposed to CUMSand SE group rats received 4 - week voluntary wheelingexercise at the same time. The behavioral changes wereconducted by forced swimming test and eight-arm radialmaze test,and nNOS expression within Hippocampus DGwere tested with an immunohistochemical method. Re-sults：（1） Compared with the C group,immobility timesprolonged in the forced swimming test,the time of comple-ting 8 - arms radial maze prolonged and working memoryerror （ WME）, reference memory error （ RME）, totalememory error（TE） significantly increased in the eight-arm radial maze test in the SM group,nNOS expressionenhanced pressive rats,and its mechanism might be that voluntarywheeling exercise reduces the nNOS expression and weak-ens NO neurotoxicity within Hippocampus DG.