BACKGROUND Glial cell ensheathment of specific components of neuronal circuits is essential for nervous system function. Although ensheathment of axonal segments of differentiated neurons has been investigated, ensheathment of neuronal cell somas, especially during early development when neurons are extending processes and progenitor populations are expanding, is still largely unknown. METHODS To address this, we used time-lapse imaging in zebrafish during the initial formation of the dorsal root ganglia (DRG). RESULTS Our results show that DRG neurons are ensheathed throughout their entire lifespan by a progenitor population. These ensheathing cells dynamically remodel during development to ensure axons can extend away from the neuronal cell soma into the CNS and out to the skin. As a population, ensheathing cells tile each DRG neuron to ensure neurons are tightly encased. In development and in experimental cell ablation paradigms, the oval shape of DRG neurons dynamically changes during partial unensheathment. During longer extended unensheathment neuronal soma shifting is observed. We further show the intimate relationship of these ensheathing cells with the neurons leads to immediate and choreographed responses to distal axonal damage to the neuron. CONCLUSION We propose that the ensheathing cells dynamically contribute to the shape and position of neurons in the DRG by their remodeling activity during development and are primed to dynamically respond to injury of the neuron.

中文翻译：

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早在神经元分化时，鞘细胞在发育和损伤中利用神经元胞体的动态平铺。

背景技术神经元回路的特定成分的神经胶质细胞鞘对神经系统功能是必不可少的。尽管已经研究了分化神经元的轴突节段的鞘，但神经元细胞胞体的鞘，特别是在神经元扩展过程和祖细胞群扩大的早期发育期间，仍然很大程度上是未知的。方法 为了解决这个问题，我们在斑马鱼背根神经节 (DRG) 的初始形成过程中使用了延时成像。结果 我们的结果表明，DRG 神经元在其整个生命周期中都被祖细胞群包裹着。这些鞘细胞在发育过程中动态重塑，以确保轴突可以从神经元细胞体延伸到 CNS 并延伸到皮肤。作为一个人口，鞘细胞平铺每个 DRG 神经元，以确保神经元被紧密包裹。在开发和实验性细胞消融范例中，DRG 神经元的椭圆形在部分脱鞘期间动态变化。在更长的延长未鞘化期间，观察到神经元胞体转移。我们进一步表明这些鞘细胞与神经元的密切关系导致对神经元远端轴突损伤的即时和精心设计的反应。结论 我们提出，鞘细胞通过它们在发育过程中的重塑活动动态地对背根神经节中神经元的形状和位置做出贡献，并准备好对神经元的损伤做出动态反应。DRG 神经元的椭圆形状在部分脱鞘期间动态变化。在更长的延长未鞘化期间，观察到神经元胞体转移。我们进一步表明这些鞘细胞与神经元的密切关系导致对神经元远端轴突损伤的即时和精心设计的反应。结论 我们提出，鞘细胞通过它们在发育过程中的重塑活动动态地对背根神经节中神经元的形状和位置做出贡献，并准备好对神经元的损伤做出动态反应。DRG 神经元的椭圆形状在部分脱鞘期间动态变化。在更长的延长未鞘化期间，观察到神经元胞体转移。我们进一步表明这些鞘细胞与神经元的密切关系导致对神经元远端轴突损伤的即时和精心设计的反应。结论 我们提出，鞘细胞通过它们在发育过程中的重塑活动动态地对背根神经节中神经元的形状和位置做出贡献，并准备好对神经元的损伤做出动态反应。