大鼠中枢神经系统衰老的形态学研究Ⅳ.大脑皮质锥体细胞树突棘的数量变化

用6、12与31个月的雄性Wistar大鼠的大脑Krieg 2、3区皮质,对其V层大锥体细胞的五段50μm长度内的树突棘做形态学定量研究。在Golgi法的切片中共计数了三个年龄组的151个细胞的725段树突的棘密度。结果表明,老年大鼠比成年和青年大鼠的棘密度普遍下降。其中以基树突与侧树突棘度下降最显著(减少24％左右),顶树突只中段有明显减少。老年大鼠锥体细胞还常出现胞体、树突及其分支的明显形态改变。

MORPHOLOGIC STUDIES ON THE AGING CHANGES IN CENTRAL NERVOUS SYSTEM OF RAT. VI. QUANTITATIVE CHANGES OF DENDRITIC SPINES OF PYRAMIDAL NEURONS IN CEREBRAL CORTEX.

The cerebral cortices of Krieg's 2, J areas in young, adult and senescent Wistar rats were observed with Golgi method. In each age group, 10 large pyramidal neurons in layer V were selected in every animal to calculate the number of spines on 50 microns length taking from five segments of different dendrirtes. In these three groups of animals, there were 151 cells and 725 dendritic segments to be counted by virtue of micrometer. The data demonstrated that the density of spines in senescent rats decreased when compared with those of the young and adult groups. Among the five segments, the same obvious decrease of spine occurred at basal and oblique dendrites (about 24% of mean decline in each), and a less decrasing amount occurred at middle apical segment. Some distinct morphologic changes occurred frequently in cell body, dendritic shape and dendritic branch pattern in senescent rats.The presumptive roles of the loss of denddritic spinces and it's correlation with the neuro-nal loss were discussed.