Neurofilaments (NFs) are the most abundant cytoskeletal filaments undergoing 'slow axonal transport' in axons, and the population of NFs determines the axonal morphology. Both in vitro and ex-vivo experimental evidences show that the caliber of node is much thinner and the number of NFs in the node is much lower than the internode. Based on the Continuity equation, lower population of NFs indicates faster transport velocity. We propose that the local acceleration of NFs transport at node may result from the higher on-track rate [Formula: see text] or higher transition rate [Formula: see text] from pausing to running. We construct a segment of axon including both node and internode, and inject NFs by a fixed flux into it continuously. By upregulating transition rate of either [Formula: see text] or [Formula: see text] locally at the Node of Ranvier in the '6-state'model, we successfully accelerate NFs velocity and reproduce constriction of nodes. Our work demonstrates that local modulation of NF kinetics can change NFs distribution and shape the morphology of Node of Ranvier.

中文翻译：

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Ranvier节点处神经丝运输的局部调节

神经丝 (NFs) 是在轴突中经历“缓慢轴突运输”的最丰富的细胞骨架丝，并且 NFs 的数量决定了轴突的形态。体外和离体实验证据表明，节点的口径要细得多，节点内的NFs数量远低于节间。根据连续性方程，NFs 的数量越少表明传输速度越快。我们提出，节点处 NFs 传输的局部加速可能是由于较高的在轨率 [公式：见文本] 或更高的转换率 [公式：见文本] 从暂停到运行。我们构建了一段轴突，包括节点和节间，并通过固定通量将 NFs 连续注入其中。通过上调 [公式：见正文] 或 [公式：见文本] 在“6 态”模型中的 Ranvier 节点上，我们成功地加速了 NF 的速度并重现了节点的收缩。我们的工作表明，NF 动力学的局部调制可以改变 NFs 分布并塑造 Ranvier 节点的形态。