POSTNATAL-DEVELOPMENT OF CEREBELLAR CORTEX IN RAT .1. EXTERNAL GERMINAL LAYER AND TRANSITIONAL MOLECULAR LAYER
POSTNATAL-DEVELOPMENT OF CEREBELLAR CORTEX IN RAT .1. EXTERNAL GERMINAL LAYER AND TRANSITIONAL MOLECULAR LAYER
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DOI：
10.1002/cne.901450305
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发表时间：
1972-01-01
影响因子：
2.5
通讯作者：
ALTMAN, J
中科院分区：
文献类型：
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作者：
ALTMAN, J
应用组织学、组织化学、放射自显影和电镜技术，研究了0、3、5、7、10、12、15、21和30日龄大鼠小脑皮质外胚层增殖区细胞的增殖和篮状细胞、星状细胞和颗粒细胞分化的早期阶段。在0-9天之间，增殖区具有恒定的4 - 5个细胞的深度;在此期间，在下面的前迁移区中的双极细胞的深度从0-6个细胞增加。此后，两个区域的细胞深度都有所下降。在预迁移区有一个梯度的长度挤压过程的双极细胞（浓度的这种配置文件），未来的平行纤维。当细胞达到最后长度时，细胞体向下迁移，平行纤维成为分子层上部区域的一部分，这样，通过堆积过程，平行纤维从下向上在其他平行纤维的表面上不断形成，结果，外部的胚芽层不断被向上推。这种设计使得组装水平取向的平行纤维的非常长、薄和直的梁的矩阵成为可能，这些梁根据它们的年龄垂直地堆积。当突触发生在第二周开始在分子层扩大的连接过程中产生的这一层的生长spurt. Basketcells在6-7天形成的锥体被逮捕在形成的分子层，因为他们的突起是在一个直角的平行纤维床的基础。因此，分子层的细胞也从底部向上堆叠，作为其分化开始的时间的函数。平行纤维突触可以看到分化的篮细胞早在第七天，形成与这些抑制性中间神经元之前，他们与浦肯野细胞的棘突触的连接。
The multiplication of cells in the proliferative zone of the external germinal layer and the early steps in the differentiation of basket, stellate and granule cells were studied in the cerebellar cortex of rats aged 0, 3, 5, 7, 10, 12, 15, 21 and 30 days with histological, histochemical, autoradiographic and electron microscopic techniques. Between 0–9 days the proliferative zone has a constant depth of four to five cells; the bipolar cells in the underlying premigratory zone increase in depth during this period from 0–6 cells. Thereafter, there is a decline in the cell depth of both zones. In the premigratory zone there is a gradient in the length of the extruded processes of the bipolar cells (concentration of such profiles), the future parallel fibers. Presumably when the latter reach their final length, the cell body migrates downward and the parallel fiber becomes part of the upper zone of the molecular layer.Thus, parallel fibers are progessively formed on the surface of others from the bottom upward by a stacking process and the external germinal layer, as a consequence, is continually pushed upward. This design makes possible the assembly of a matrix of very long, thin and straight beams of horizontally oriented parallel fibers which pile up vertically according to their age. When synaptogenesis starts during the second week in the molecular layer the enlarging junctional processes produce a spurt in the growth of this layer.Basket cells which are formed in the pyramis on days 6–7 are arrested in the formative molecular layer because their processes are oriented at a right angle to the underlying bed of parallel fibers. Therefore, there is also a stacking of the cells of the molecular layer from the bottom upward as a function of time of onset of their differentiation. Parallel fiber synapses may be seen on differentiating basket cells as early as the seventh day, forming connections with these inhibitory interneurons before they synapse with spines of Purkinje cells.