论文部分内容阅读
本工作采用酪氨酸羟化酶(HT)免疫细胞化学技术结合电镜技术,研究了大白鼠黑质多巴胺细胞发育早期的分化和分布的特征。最早的TH阳性细胞首先于胚胎13天在中脑吻端的腹侧出现;随后出现的TH阳性细胞从尾端和背侧逐渐加入早先出现的TH细胞。在染色程度和细胞形态上,黑质区域内存在一个腹—背和外—内方向上的梯度,即位于腹侧和外侧的细胞染色较深、细胞体较大、核小、突起明显;而位于背侧和内侧的TH阳性细胞染色较淡、细胞体小、核大、突起不明显。最早的黑质——纹状体纤维由位于中脑黑质外侧部分的TH细胞首先发出。电镜下,发育早期的TH阳性细胞中都能见到粗面内质网。随着发育进程,TH阳性反应加深,粗面内质网和其它细胞器也相应增加。结合前人有关黑质细胞发生和迁移的放射自显影研究结果,本工作提示,黑质多巴胺细胞在停止迁移后开始化学分化,化学分化与细胞形态分化同步,并存在一定的时空先后顺序,这一顺序可能由神经发生的先后顺序决定。
In this work, tyrosine hydroxylase (HT) immunocytochemistry was used in combination with electron microscopy to study the differentiation and distribution of dopamine in rat substantia nigra during early development. The earliest TH-positive cells first appeared on the ventral side of midbrain kisses on day 13 of the embryo; subsequent appearances of TH-positive cells gradually increased the appearance of pre-existing TH cells from the caudal and dorsal sides. In terms of the degree of staining and cell morphology, there is a gradient in the ventral-dorsal and lateral-medial directions in the substantia nigra region, ie the cells located ventral and lateral are deeply stained, the cell body is large, the nucleus is small, and the protrusions are conspicuous; while The dorsal and medial TH-positive cells stained lighter, small cell body, large nuclei, protrusions were not obvious. The earliest substantia nigra - striatum fibers were first emitted by TH cells located in the lateral portion of the mid substantia nigra. Under the electron microscope, the rough endoplasmic reticulum can be seen in the TH-positive cells in early development. As the developmental process, TH positive reaction deepened, rough endoplasmic reticulum and other organelles also increased accordingly. Combined with the previous studies on autoradiography of the occurrence and migration of nigral cells, this work suggests that the dopaminergic neurons in the substantia nigra begin to chemically differentiate after ceasing to migrate, and the chemical differentiation is synchronized with the morphological differentiation of cells, and there is a certain order of space-time A sequence may be determined by the sequence of neurogenesis.