Experimental reorganization of the cerebellar cortex. II. Effects of elimination of most microneurons with prolonged x‐irradiation started at four days
Experimental reorganization of the cerebellar cortex. II. Effects of elimination of most microneurons with prolonged x‐irradiation started at four days
复制标题
小脑皮质的实验性重组 II. 长时间 X 射线照射消除大多数微神经元的效果从四天开始。
DOI：
10.1002/cne.901490202
复制
发表时间：
1973
影响因子：
2.5
通讯作者：
W. J. Anderson
中科院分区：
文献类型：
--
作者：
J. Altman;W. J. Anderson
Long - Evans大鼠的头部从出生后第4天开始接受重复剂量的低水平x射线照射，这基本上阻止了篮状细胞、星形细胞和颗粒细胞的形成，除了最早形成的小叶（结节和小叶）。在30天大的动物中，用光镜和电子显微镜检查了这种治疗的形态发生和突触发生作用，特别注意了锥体。虽然浦肯野细胞在开始照射时呈单层结构，顶极向上，但照射后细胞分散，树突方向随机。这种继发性定向障碍归因于在被阻滞的小脑中没有足够的空间来容纳快速扩张的浦肯野细胞。虽然篮状细胞终末缺乏，但篮状终末在浦肯野细胞的体细胞上形成，显然是由这些细胞的轴突侧枝反复形成的。浦肯野树突棘上最常见的突触是由攀爬纤维形成的，但包括神经胶质过程在内的其他成分也与棘上的突触后位点接触。许多长满苔藓的纤维终端到达表面。在平行纤维存在的地方，它们通常比未受辐射的动物更粗，并且含有神经丝。在这些小脑中未见病理改变，可能除了许多浦肯野细胞的细胞核过度分叶化。
The heads of Long‐Evans rats were irradiated from the fourth day after birth with a schedule of repeated doses of low‐level x‐ray which essentially prevented the formation of basket, stellate and granule cells in all except the earliest‐forming lobules (nodulus and uvula). The morphogenic and synaptogenic effects of this treatment were examined with light and electron microscopy in 30 day old animals, with particular attention paid to the pyramis. Although when irradiation was started the Purkinje cells formed a monolayer and had upward oriented apical poles, they became scattered later and had randomly oriented dendrites. This secondary disorientation was attributed to insufficient space available in the arrested cerebellum for the rapidly expanding Purkinje cells. Although basket cell terminals were scarce, basket cell‐like terminals were formed on the somata of Purkinje cells, apparently by recurrent axon collaterals of these cells. The most common synapses with the thorns of Purkinje dendrites were formed by climbing fibers but other elements, including glial processes, were also in contact with postsynaptic loci on the thorns. Many mossy fiber terminals reached the surface. Where parallel fibers were present they were often thicker than in unirradiated animals and contained neurofilaments. No pathological changes were seen in these cerebella, with the possible exception of excessive lobulation of the nuclei of many Purkinje cells.