跑步锻炼对抑郁症模型大鼠大脑白质及白质内有髓神经纤维影响的体视学研究

The stereological studies of the effects of exercise on the white matter and the myelinated fibers of the white matter in depressied rats

目的运用无偏体视学方法定量研究慢性不可预见性应激(CUS)所致的抑郁模型大鼠大脑白质及白质内有髓神经纤维的改变及跑步锻炼对其改变的影响。方法雄性SD大鼠,适应环境1w,筛选出符合条件的40只大鼠将其随机分为空白对照组(10只)和抑郁模型组(30只)。从第2w开始模型组动物采用慢性不可预见性应激的方法建立抑郁症大鼠模型,为期4w。选取建模成功的大鼠20只,随机等分为模型对照组和模型跑步组,模型跑步组大鼠进行4w的跑步锻炼。采用糖水偏好试验、强迫游泳试验及旷场试验进行行为学检测;利用体视学方法测定白质的总体积及白质内有髓神经纤维的总长度。结果应激第4w末,与空白对照组相比,抑郁模型组大鼠体重、糖水偏好百分比、旷场得分均降低,强迫游泳不动时间增加,差异具有统计学意义(P<0.05);跑步锻炼四周后,模型跑步组糖水偏好百分比显著性高于模型对照组(P<0.05)。模型对照组大鼠大脑白质总体积、有髓神经纤维总长度均显著性低于空白对照组(P<0.01);与模型对照组相比,模型跑步组大鼠大脑白质总体积及有髓神经纤维总长度显著性增加(P<0.05);与空白对照组相比,模型跑步组大鼠大脑白质总体积无显著性差异(P>0.05),白质内有髓神经纤维总长度显著性降低(P<0.05)。结论跑步锻炼对抑郁症模型大鼠大脑白质内有髓神经纤维改变具有积极保护作用,这可能是跑步锻炼治疗抑郁症的重要结构基础之一。

Objective To investigate the changes of the white matter and the myelinated fibers in the white matter of chronic unpredicted stress(CUS)depression model rats and the effects of running exercise on those changes with the stereological method.Methods Male SD rats were adapted to the environment for one week.Then male SD rats were randomly divided into the control group(10rats)and depression model group(30rats).From the second week,the depression model was made by giving rats the chronic unpredicted stress for four weeks.20 successfully made depression model rats were randomly divided into the control depression group(10rats)without running and the running depression group(10rats).The running lusted four weeks.The behavior was tested with the sucrose preference test,forced swimming test and open-field test.The white matter volume and the total length of the myelinated fibers in the white matter were estimated using the stereological methods.Results After 4-week stress,when compared to those of the control group,the body weight,sucrose preference and the scores on the open-field test were significantly decreased,and the immobility time in the forced swimming was significantly increased in thedepression model group(P<0.05).After 4-week running exercise,the sucrose preference was significantly increased in the running depression group rats when compared to that of the control depression rats.The total white matter volume and the total length of the myelinated fibers in the white matter of the control depression group were significantly less than those of the control group(p < 0.01).When compared to those of the control depression group,the total white matter volume and the total length of the myelinated fibers in the white matter were significantly increased in the running depression group(P<0.05).The total white matter volume was not significantly different between the running depression group and the control group(P>0.05),but the total length of the myelinated fibers in the white matter of the running depression group was significantly decreased when compared to that of the control group(P< 0.05).Conclusion Running exercise was protective effects on the white matter and the myelinated fibers of the white matter in depressed rats,which might be one of the important structural bases for running exercise induced treatment of depression.