ELECTRON-MICROSCOPIC ANALYSIS OF POSTNATAL HISTOGENESIS IN CEREBELLAR CORTEX OF STAGGERER MUTANT MICE
ELECTRON-MICROSCOPIC ANALYSIS OF POSTNATAL HISTOGENESIS IN CEREBELLAR CORTEX OF STAGGERER MUTANT MICE
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DOI：
10.1002/cne.901790408
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发表时间：
1978-01-01
影响因子：
2.5
通讯作者：
SIDMAN, RL
中科院分区：
文献类型：
--
作者：
LANDIS, DMD;SIDMAN, RL
出生后小脑皮质的发育进行了比较，在staggerer突变和未受影响的同窝小鼠。从出生后第3天到第21天左右，蹒跚小鼠的外颗粒层厚度和面积减少，有丝分裂后颗粒细胞神经元的数量减少。这些颗粒细胞的产生似乎正常分化，与显着的例外，他们只形成原始连接与浦肯野细胞树突状轴。这些特化的连接不被正常的平行纤维（浦肯野棘突触）取代，并在第3周消失。浦肯野细胞胞体和树突在所有阶段都比正常小。树突不局限于矢状面，在正常的和，独特的突变体或其他动物中描述的日期，他们表现出几乎没有小枝刺。颗粒细胞和浦肯野细胞的所有其他皮质突触关系，包括攀缘纤维（浦肯野棘突触），在性质上似乎正常。到第28天，几乎所有的交错颗粒细胞都已退化。主要的遗传缺陷仍然未知，形态异常可能是由于颗粒细胞和浦肯野细胞之间的正常发育关系的块。小细胞大小和未能形成小枝棘表明，浦肯野细胞异常可能更接近突变基因的主要影响比更明显的发育不全和颗粒细胞神经元变性。
Postnatal development of the cerebellar cortex was compared in staggerer mutant and unaffected littermate mice. From postnatal day 3 to about day 21 the external granular layer in staggerer mice is decreased in thickness and area, and the number of postmitotic granule cell neurons is reduced. Those granule cells that are generated seem to differentiate normally, with the remarkable exception that they form only primitive junctions with Purkinje cell dendritic shafts. These specialized junctions are not superseded by the normal parallel fiber (Purkinje spine synapses) and disappear by the 3rd wk. Purkinje cell somata and dendrites are smaller than normal at all stages. The dendrites are not confined to the sagittal plane as in the normal and, unique among mutant or other animals described to date, they exhibit virtually no branchlet spines. All other cortical synaptic relations of granule and Purkinje cells, including climbing fiber (Purkinje spine synapses) appear qualitatively normal. By 28 days virtually all staggerer granule cells have degenerated. The primary genetic defect remains unknown; the morphological abnormalities may be attributable to a block in the normal developmental relationship between granule cells and Purkinje cells. The small cell size and failure to form branchlet spines suggest that the Purkinje cell abnormality may be closer to the primary effect of the mutant gene than the more flagrant hypoplasia and degeneration of granule cell neurons.