选择津白Ⅱ号大白鼠20只分成三组,即幼龄鼠组、成龄鼠组和老龄鼠组,用H-E染色、尼氏染色在光镜下观察及超薄切片在电镜下观察,比较三组动物的脊髓前角细胞、前角内及脊神经节内脊髓神经纤维衰老的形态学变化。光镜观察:幼龄鼠组和成龄鼠组的前角细胞密集,尼氏体分布均匀,核中 Twenty rats of Jinbai Ⅱ were selected and divided into three groups: young group, adult group and aging group. The rats were observed with HE staining, Nissl staining under light microscope and ultrathin section under electron microscope. Morphologic changes of spinal nerve fibers in spinal cord anterior horn cells, anterior horn and spinal ganglia of three groups of animals. Light microscopy: young mice and adult mice group anterior horn cells dense, uniform distribution of Nissl, the nucleus