Bhat M A, Rios J C, Lu Y, Garcia-Fresco G P, Ching W, St Martin M, Li J, Einheber S, Chesler M, Rosenbluth J, Salzer J L, Bellen H J
Cardiovascular Research Institute, Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA.
Neuron. 2001 May;30(2):369-83. doi: 10.1016/s0896-6273(01)00294-x.
Myelinated fibers are organized into distinct domains that are necessary for saltatory conduction. These domains include the nodes of Ranvier and the flanking paranodal regions where glial cells closely appose and form specialized septate-like junctions with axons. These junctions contain a Drosophila Neurexin IV-related protein, Caspr/Paranodin (NCP1). Mice that lack NCP1 exhibit tremor, ataxia, and significant motor paresis. In the absence of NCP1, normal paranodal junctions fail to form, and the organization of the paranodal loops is disrupted. Contactin is undetectable in the paranodes, and K(+) channels are displaced from the juxtaparanodal into the paranodal domains. Loss of NCP1 also results in a severe decrease in peripheral nerve conduction velocity. These results show a critical role for NCP1 in the delineation of specific axonal domains and the axon-glia interactions required for normal saltatory conduction.
有髓纤维被组织成不同的区域，这些区域对于跳跃式传导是必需的。这些区域包括郎飞结和相邻的旁结区域，在旁结区域，神经胶质细胞紧密贴附并与轴突形成特殊的类隔膜连接。这些连接包含一种与果蝇神经细胞粘附分子IV相关的蛋白质，Caspr/Paranodin（NCP1）。缺乏NCP1的小鼠表现出震颤、共济失调和明显的运动性麻痹。在没有NCP1的情况下，正常的旁结连接无法形成，旁结环的组织结构被破坏。在旁结中检测不到Contactin，并且钾离子通道从毗邻旁结区域移位到旁结区域。NCP1的缺失还导致外周神经传导速度严重下降。这些结果表明NCP1在特定轴突区域的界定以及正常跳跃式传导所需的轴突-神经胶质细胞相互作用中起关键作用。
