Glial cells in transected optic nerves of immature rats .1. An analysis of individual cells by intracellular dye-injection
Glial cells in transected optic nerves of immature rats .1. An analysis of individual cells by intracellular dye-injection
复制标题
DOI：
10.1007/bf02284808
复制
发表时间：
1996-06-01
期刊：
影响因子：
--
通讯作者：
Colquhoun, K
中科院分区：
文献类型：
--
作者：
Butt, AM;Colquhoun, K
在21日龄的未成熟大鼠（P21）中，研究了单侧眼球摘除后视神经中神经胶质对沃勒变性的反应。在完整的神经，在postenucleation第21天，并在未处理的P21大鼠的正常神经，通过相关的激光扫描共聚焦显微镜和照相机的单细胞清晰图纸的三维形态的染料填充的神经胶质细胞。在正常和横断神经中，大多数充满染料的细胞与星形胶质细胞结合（分别为54%和65%）。在正常的P21神经，占主导地位的星形胶质细胞形式有一个复杂的星状形态，并有一个位于中央的细胞体，从分支过程随机延伸。另外两种不同的形式是横向和纵向星形胶质细胞，它们分别在垂直或平行于神经长轴的平面上具有极化过程延伸。这些形式在横断神经中也被识别，但横断神经中的星形胶质细胞总体上具有简单的形态，并且延伸很少，密集的突起很少分支。星形胶质细胞形态的定量分析证实，个别星形胶质细胞进行了相当大的重塑响应沃勒变性。一个突出的反应是星形胶质细胞撤回放射状突起，并沿纵向延伸更大比例的突起，平行于神经的长轴和沿着退化轴突的路线。横切神经的另一个显著特征是新的纵向形式和肥大的星形胶质细胞的发展。这些结果表明，所有的星形胶质细胞成为反应后，去核和胶质瘢痕的形成不是一个单一的星形胶质细胞亚型的功能。横切神经中的少突胶质细胞失去了髓鞘，表现为具有许多放射状延伸的分叉突起的小细胞，但也识别出少量少突胶质细胞，它们显然支持髓鞘（9%，而正常神经中为40%）。此外，在横断神经中有大量的不确定细胞（26%，而正常神经中为6%），尽管其中一些被鉴定为小胶质细胞/巨噬细胞，但得出的结论是，许多可能是去分化的少突胶质细胞。
The glial response to Wallerian degeneration was studied in optic nerves following unilateral enucleation in immature rats, aged 21 days old (P21). The three-dimensional morphology of dye-filled glia was determined in intact nerves, at postenucleation day 21 and in normal nerves from untreated P21 rats, by correlating laser scanning confocal microscopy and camera lucida drawings of single cells. In normal and transected nerves, the majority of dye-filled cells comprized astrocytes (54% and 65%, respectively). In normal P21 nerves, the predominant astrocyte form had a complex stellate morphology and had a centrally-located cell body from which branching processes extended randomly. Two other distinct forms were transverse and longitudinal astrocytes, which had a polarized process extension in a plane perpendicular or parallel to the long axis of the nerve, respectively. These forms were recognized in transected nerves also, but astrocytes in transected nerves had a simple morphology on the whole, and extended few, dense processes which branched infrequently. Quantitative analysis of astrocyte morphology confirmed that individual astrocytes underwent considerable remodelling in response to Wallerian degeneration. A prominent reaction was that astrocytes had withdrawn radial processes and extended a greater proportion of processes longitudinally, parallel to the long axis of the nerve and along the course of degenerated axons. A further, notable feature of transected nerves was the development of novel longitudinal forms and of hypertrophic astroglia. These results indicated that all astrocytes became reactive following enucleation and that glial scar formation was not the function of a single astrocyte subtype. Oligodendrocytes in transected nerves had lost their myelin sheaths and appeared as small cells with numerous bifurcating processes which extended radially, but a small number of oligodendrocytes were recognized which apparently supported myelin sheaths (9%, compared to 40% in normal nerves). In addition, there was a significant population of indeterminate cells in transected nerves (26%, compared to 6% in normal nerves) and, although some of these were identified as microglia/macrophages, it was concluded that many were likely to be dedifferentiated oligodendrocytes.