Crossing the floor plate triggers sharp turning of commissural axons
Crossing the floor plate triggers sharp turning of commissural axons
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DOI：
10.1006/dbio.2001.0321
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发表时间：
2001-08-01
影响因子：
2.7
通讯作者：
Murakami, F
中科院分区：
文献类型：
--
作者：
Shirasaki, R;Murakami, F
在脊椎动物中枢神经系统的发育过程中，连合轴突最初向腹侧中线底板方向生长。穿过底板后，它们的轨迹突然从圆周向纵轴改变。尽管最近的研究已经解开了控制这些轴突沿周轴导航的机制，但那些导致从周向轨迹向纵向轨迹转变的机制仍不清楚。在这里，我们使用大鼠后脑的体外标本，研究了与底板的相互作用是否是启动连合轴突轨迹转换的先决条件。我们发现，后脑中的连合轴突一旦穿过底板，就会急剧转向纵向生长。相反，在去除底板的准备中延伸的轴突继续沿圆周生长，忽略了假设的转折点。这些结果表明，连接轴突与底板细胞的预先相互作用是这些轴突激活导航程序所需的关键步骤，以使它们的轴突轨迹从圆周向纵轴改变。(C)2001年学术出版社。
During development of the vertebrate CNS, commissural axons initially grow circumferentially toward the ventral midline floor plate. After crossing the floor plate, they abruptly change their trajectory from the circumferential to the longitudinal axis. Although recent studies have unraveled the mechanisms that control navigation of these axons along the circumferential axis those that result in the transition from circumferential to longitudinal trajectory remain unknown. Here, we examined whether an interaction with the floor plate is a prerequisite for the initiation of trajectory transition of commissural axons, using in vitro preparations of the rat metencephalon. We found that commissural axons in the metencephalon, once having crossed the floor plate, turned sharply to grow longitudinally. In contrast, axons extending in floor plate-deleted preparations, continued to grow circumferentially, ignoring the hypothetical turning point. These results suggest that a prior interaction of commissural axons with floor plate cells is a key step for these axons to activate a navigation program required for their change in axonal trajectory from the circumferential to the longitudinal axis. (C) 2001 Academic Press.