The morphology of growth cones of regenerating optic nerve axons
The morphology of growth cones of regenerating optic nerve axons
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再生视神经轴突生长锥的形态
DOI：
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发表时间：
1985
期刊：
影响因子：
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通讯作者：
Dan E. Matsumoto
中科院分区：
文献类型：
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作者：
F. Scalia;Dan E. Matsumoto
在再生的早期和后期，使用辣根过氧化物酶（HRP）纤维填充方法，通过光学和电子显微镜检查成年青蛙（Rana pipiens）再生视神经轴突生长锥的形态。通过挤压眼眶中的视神经单侧启动视神经再生。通过在 24-48 小时内切断靠近眼睛的受影响神经来完成纤维填充。在牺牲并将 HRP 应用于中央树桩之前。在视神经、视交叉、视束、顶盖前神经毡和视顶盖中观察到再生轴突及其生长锥。正常轴突的生长锥形状和大小各不相同。在顶盖前神经毡和视顶盖中观察到类似于体外常见的扁平叶状生长锥。在所有检查阶段的整个视神经通路中都观察到其他具有蠕虫状、披针形、匙形和球根状的生长锥，尽管较长（长达 70 μm）的蠕虫状结构仅在生长早期出现在视束中。 8周时，对侧视顶盖中的两个生长锥获得了几乎完整的连续切片重建。再生时间。一个被薄薄地压平（某些地方为 30-50 nm）并广泛延伸（直径 8 μm）与神经元周围核接触。另一个在切断的、不可再生的有髓鞘轴突的盲端上形成了一个罩子，除了其末端在生长锥的范围内之外，轴突的外观正常。生长锥之间的形态变化与其他描述性体内研究和有关生长锥运动的观点进行了讨论。
The morphology of growth cones of regenerating optic nerve axons was examined by light and electron microscopy in adult frogs (Rana pipiens), using a horseradish peroxidase (HRP) fiber‐filling method, during early and later phases of regeneration. Optic nerve regeneration was initiated unilaterally by crushing the optic nerve in mid‐orbit. Fiber filling was accomplished by severing the affected nerve closer to the eye 24–48 hrs. prior to sacrifice and applying HRP to the central stump. Regenerating axons and their growth cones were observed in the optic nerves, chiasma, tract, pretectal neuropil, and optic tectum. Growth cones of normal‐appearing axons varied in shape and size. Flattened, foliate growth cones similar to those commonly described in vitro were observed in the pretectal neuropil and optic tectum. Other growth cones having vermiform, lanceolate, spatulate, and bulbous forms were observed throughout the optic pathway at all stages examined, although the longer (up to 70 μm) wormlike structures appeared only in the optic tract during the early period of outgrowth. Nearly complete serial‐section reconstructions were obtained for two growth cones in the contralateral optic tectum at 8 wks. regeneration time. One was thinly flattened (to 30–50 nm in places) and extended broadly (8 μm in diameter) in contact with a nouronal perikaryon. The other formed a hood over the blind end of a severed, nonregenerating myelinated axon, which was normal‐appearing except at its end within the confines of the growth cone. Morphological variation among the growth cones is discussed in relation to other descriptive in vivo studies and views concerning growth cone motility.