摘要
HRP—CB标记结合sholl分析方法分析研究5、13、24月龄三个年龄组C57BL/6J小鼠脊髓前角α—运动神经元树突结构的可塑性变化,以及不同时间的长期适量运动(跑转笼)对运动神经元树突结构可塑性变化的可能作用。以同年龄对照组心重/体重比率均值的二倍标准差(X+2SD)做为运动有效标准。结果在三个年龄对照组中,老年鼠(对照组Ⅱ)神经元树突野缩小,树突分支数和总长度明显减少(P<0.05),以远离胞体的分支丢失为主。经过8和19个月运动训练后,脊髓前角运动神经元树突野扩大,分支数和树突总长度明显增加(P<0.01),甚至超过青年对照,以近胞体分支的增生更明显。结果表明,长期的适量运动能够延缓衰老过程中小鼠脊髓前角运动神经元树突的丢失,促进树突的可塑性增生。
The study was performed to analyse quantitatively the plastical changes in dendritic branching pattens of C57BL/6J mouse spinal motoneurons following prolonged training(running wheel)initiated at 4.5month of age.spinal α—motonerons were labelled with horseradish peroxidase conjugated to the β—subunit of cholera toxin(HRP—CB).We set the criterion for effective training in the trained mice such that the mean heart— to—body ratio should be at least 2 SD above the mean in the age—matched group.In three controls,dendritic field area was reduced,numbers of dendritic branchs and total dendritic length were significantly decreased dur- ing aging.Moreover,terminal tree situated farther from the neuronal soma more vulnerable to regression. After 8 months and 19 months physical training,dendritic field area increased,numbers of branchs and total dendritic length also increased significantly.Dendritic regrowth occurred in proximal regions of network.The data indicated that prolonged moderate training could modify the loss of dendrites of spinal α—motoneurons and stimulate the plastical regrowth of dendrites.
关键词
脊髓
运动神经元
树突
α—Motoneuron
Neuronal plasticity
Aging
Physical activity
