猫腰髓白质年龄相关的形态学变化

以青年成年猫(1-3龄,2-2．5 kg)和老年猫(12龄,3-3．5kg)L6段脊髓白质为研究对象,用 神经丝蛋白(NF)免疫染色显示神经纤维,用改良的Holzer结晶紫染色显示所有胶质细胞并用成年动物Golgi 法显示其形态,用胶质纤维酸性蛋白(GFAP)免疫染色显示星形胶质细胞。光镜下对青年猫与老年猫腰髓白质 中神经纤维和胶质细胞进行形态学观察和定量研究。与青年猫相比,老年猫腰髓白质中的神经纤维密度显著下 降(P

Age-related Morphological Changes in the White Matter of Cat Lumbar Spinal Cord

In order to investigate age-related morphological changes in the white matter of the lumbar spinal cord in young adult and old cats, several techniques were used. (1) Immunostaining of neurofilaments (NF) was used to identify nerve fibres; (2) modified Holzer crystal violet to show all the glial cells; (3) immunoreaction of glial fibrillary acid protein (GFAP) to exhibit the astrocytes; (4) the Golgi method to display the morphology of glial cells and astrocytes in the white matter. Under the microscope, the fibres and glial cells were observed and quantitatively studied. Compared with young cats, old cats showed significantly lower density of nerve fibres (P < 0.01) and weaker staining of the NF immunore-activity . However, the density of glial cells and astrocytes ( P < 0.01) in old cats is significantly greater than in young adult cats. In addition, astrocytes in old cats were more hypertrophic, with stronger immunoreactivity of GFAP substance than in young ones. This indicates that there is a loss of nerve fibres accompanied by an obvious glial hyperplasia in the white matter of the aging cat spinal cord. The above results suggest that the loss of nerve fibres in the white matter of old cats may be an important factor that underlies the functional decline of signal transmission and processing in the spinal cord during ageing. The activity enhancement of glial cells in old cats may provide a protective effect on surviving nerve fibers from further degradation during senescence.