POSTNATAL-DEVELOPMENT OF CEREBELLAR CORTEX IN RAT .2. PHASES IN MATURATION OF PURKINJE-CELLS AND OF MOLECULAR LAYER
POSTNATAL-DEVELOPMENT OF CEREBELLAR CORTEX IN RAT .2. PHASES IN MATURATION OF PURKINJE-CELLS AND OF MOLECULAR LAYER
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DOI：
10.1002/cne.901450402
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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：
--
作者：
ALTMAN, J
用组织学(含高尔基体)、组织化学、放射自显影和电子显微镜技术，对0、3、5、7、10、12、15、21和30日龄大鼠小脑皮质浦肯野细胞和分子层的生长和突触成熟进行了研究。浦肯野细胞的成熟分为五个阶段。在第一阶段，浦肯野细胞分散排列成单层，但仍很少或没有形成突触。接下来，出现了两种暂时性结构：由“网状”︁细胞质组成的肥大的顶锥，以及与攀援纤维建立明显不对称突触的外侧周突。在第三阶段，胞体周围突起消失；“网状”︁细胞质向上流入生长中的树突；胞体被篮状细胞组成的永久的、不明显的、对称的突触侵入；最后，胞体被胶质突起包围，标志着胞体突触成熟的结束。在第四阶段，平行纤维与分子层下半部的树突形成突触。在外生发层消失后的第五阶段，平行纤维与上层分子层的树突棘建立突触。分子层突触发生的进行曲︁自下而上表现为三个连续的事件：被覆小泡的出现和消失的初始梯度，预示着突触发生；随后突触形成的类似趋势；最后，浦肯野细胞树突和平行纤维之间同一胶质过程的插入，标志着突触发生的停止。
The growth and synaptic maturation of Purkinje cells and of the molecular layer were studied in the cerebellar cortex of rats aged 0, 3, 5, 7, 10, 12, 15, 21 and 30 days with histological (including Golgi), histochemical, autoradiographic and electron microscopic techniques. Five phases were distinguished in the maturation of Purkinje cells. During the first phase, Purkinje cells become dispersed and aligned in a monolayer but as yet few or no synapses are formed. Next, two transient structures appear: a hypertrophied apical cone composed of „reticular”︁ cytoplasm, and lateral perisomatic processes which establish conspicuous asymmetrical synapses with climbing fibers. During the third phase the perisomatic processes disappear; the „reticular”︁ cytoplasm streams upward into the growing dendrites; the soma is invaded by permanent inconspicuous, symmetrical synapses of basket cells; and, finally, it is surrounded by glial processes, which marks the end of the synaptic maturation of the soma. During the fourth phase parallel fibers form synapses with dendritritic spines in the lower half of the molecular layer. During the fifth phase, which occurs after the disappearance of the external germinal layer, parallel fibers establish synapses with dendritic spines in the upper molecular layer. The „march”︁ of synaptogenesis in the molecular layer from the bottom upward is characterized by three successive events: an initial gradient in the appearance and disappearance of coated vesicles, heralding synaptogenesis; a similar subsequent trend in the formation of synapses; and finally, the interposition in the same sequence of glial processes between Purkinje cell dendrities and parallel fibers, marking the cessation of synaptogenesis.