人胎黑质神经元发育的初步观察

Preliminary observation of the neuronal development in the human fetsl substantia nigra

应用尼氏染色方法,观察第3～10月人胎黑质神经元的分布、数量和形态学发育变化。结果如下:①在人胎第3～10月,黑质神经元位于中脑腹侧大脑脚底与红核之间,并可区分为腹侧细胞稀疏的网状部和背则细胞密集的致密部。致密部在第3～4月为连续的细胞带,第5月以后渐变间断而形成明显的细胞群。②随着胎龄增加,每张中脑横切片上黑质神经元的数目略有减少,神经元的密度逐渐降低,尤以第8～10月最明显。③从胎龄第3～10月,黑质神经元胞体逐渐增大,胞质逐渐增多,神经元的形态从胎龄早期无明显突起的小圆形细胞为主,逐渐发育为胎龄晚期的锥形和梭形细胞为主,并带有一个或多个胞质突起。结果提示:人胎黑质神经元的细胞形态学发育在胎龄3～4月时尚不成熟,而第9～10月时已接近成人。

The distribution,number and morphology of the neurons of substantia nigra in the human fetusesof 3 to 10 months were observed with Nissl stained method. The results are as follows. ①The substan-tia nigra lies in the ventral portion of the midbrain,between the crus cerebri and the red nucleus. It isdivided into the pars reticulata,a cell-poor region close to the crus cerebri and pars compacta,a cell-rich region of the fetal age of 3 to 10 months. The cell band of the pars compacta is successive in the3rd and 4th months, while it is disconnected gradually and becomes some obvious cell groupe after the5th month. ②The number and density of the neurons of substantia nigra decreases gradually in eachtransversal section with the development of the fetal age and the most remarkable decrease is seen fromthe fetal age of 8 to 10 months. ③From the fetal age of 3 to 10 months,the volume of the neuronsand the number of the cytoplasma increase gradually and the feature of the neurons has changed froma small round perikarya to a distinctly pyramidal and spindle appearance with long thin cytoplasmicprocesses. The above mentioned data suggest that the cellular development of the human fetal substantianigra might be morphologically immature in 3 to 4 months and close to the adult in 9 to 10 months.