Stanfield B B, Cowan W M
J Comp Neurol. 1979 Jun 1;185(3):393-422. doi: 10.1002/cne.901850302.
The morphology of the hippocampus and dentate gyrus in normal and reeler mice has been studied in Nissl, myelin, Golgi, Timm's sulfide silver and gold chloride-sublimate preparations. It is evident from both cell-and fiber-stained sections that despite the obvious defect in the positioning of the hippocampal pyramidal and dentate granule cells in the reeler mouse within the radial dimension, the hippocampal formation as a whole shows a normal and consistent progression of cytoarchitectonic fields along its transverse axis, and a normal and consistent progression of changes in the structure of the hippocampus and dentate gyrus along their longitudinal axes. Thus, at least in these structures, the reeler gene seems to exert its effect only in the radial dimension. Cell counts in the area dentata indicate that the number of dentate granule cells in the reeler mouse is reduced compared to that found in normal or heterozygous animals. Although it has been known for some time that the number of granule cells in the reeler cerebellar cortex is markedly reduced, this appears to be the first evidence for a reduction in cell number in a forebrain structure. All the major cell types normally found in the hippocampus and the dentate gyrus are recognizable in Golgi-stained preparations from the brains of reeler mutants. However, in both regions there are a number of abnormalities in the appearance of the cells which seem to be related to the cellular ectopia. Thus, whereas most of the pyramidal and granule cells which attain a normal position in the mutant usually have normal, or near-normal dendritic arbors, the dendrites of nearly all ectopic cells are severely distorted, both in their orientation and general configuration. In preparations stained by the Timm's sulfide silver technique it is evident that the general lamination pattern seen in normal mice is retained in the reeler hippocampus and dentate gyrus despite the gross malpositioning of many of the relevant neurons. However, although the overall laminar arrangement is preserved, there are some fairly consistent abnormalities; for example, the normal trilaminar staining pattern seen in the stratum moleculare of the dentate gyrus is replaced in the reeler by a bilaminar pattern. In gold chloride-sublimate impregnated preparations there is no obvious alignment of the astrocytes in the stratum moleculare of the dentate gyrus in either normal or reeler mice. Moreover, the distribution of the astrocytes within this zone is fairly normal in the reeler mouse, although, in general, these cells appear to be more consistently stellate in form than in normal animals.
我们采用尼氏染色、髓鞘染色、高尔基染色、蒂姆硫化银染色及氯化金升汞染色制片法，研究了正常小鼠和reeler小鼠海马体及齿状回的形态。从细胞染色和纤维染色切片中均可以明显看出，尽管reeler小鼠海马锥体细胞和齿状颗粒细胞在径向维度上的定位存在明显缺陷，但整个海马结构在横轴上的细胞构筑区域呈现出正常且一致的进展，在纵轴上，海马体和齿状回的结构变化也呈现出正常且一致的进展。因此，至少在这些结构中，reeler基因似乎仅在径向维度上发挥作用。齿状回区域的细胞计数表明，与正常或杂合动物相比，reeler小鼠的齿状颗粒细胞数量减少。虽然人们早就知道reeler小鼠小脑皮质中的颗粒细胞数量明显减少，但这似乎是首次有证据表明前脑结构中的细胞数量减少。在reeler突变体小鼠大脑的高尔基染色制片中，可以识别出海马体和齿状回中所有正常存在的主要细胞类型。然而，在这两个区域中，细胞外观存在许多异常，这些异常似乎与细胞异位有关。因此，尽管大多数在突变体中位置正常的锥体细胞和颗粒细胞通常具有正常或接近正常的树突分支，但几乎所有异位细胞的树突在方向和总体形态上都严重扭曲。在蒂姆硫化银技术染色的制片中可以明显看出，尽管许多相关神经元的位置严重错位，但正常小鼠中可见的一般分层模式在reeler小鼠的海马体和齿状回中得以保留。然而，尽管整体分层排列得以保留，但仍存在一些相当一致的异常情况；例如，齿状回分子层中正常的三层染色模式在reeler小鼠中被两层模式所取代。在氯化金升汞浸渍制片中，无论是正常小鼠还是reeler小鼠，齿状回分子层中的星形胶质细胞都没有明显的排列。此外，在reeler小鼠中，该区域内星形胶质细胞的分布相当正常，不过，总体而言，这些细胞的形态似乎比正常动物中的细胞更一致地呈星形。
