Regulation of axonal transport by local interaction with myelin

为了阐明髓鞘在轴突运输中的作用，对髓鞘突变小鼠的中枢和外周神经系统进行了免疫组织学和生化分析。在这些小鼠中，结旁轴突连接(AGJ)被破坏，但致密的髓鞘被保留。目前的结果表明，AGJ的破坏导致了含有各种轴突成分的局部轴突肿胀和轴突运输相关分子的变化。提示局部钙离子变化可能参与了这一过程。局灶性轴索肿胀最早见于髓鞘形成的早期，并随着年龄的增长而逐渐加重。轴突变性在老年小鼠中变得更加明显。因此，副阳极处的轴突-神经胶质相互作用对局部轴突内环境的稳定是重要的。

In order to elucidate the role of myelin on axonal transport, immunohistological and biochemical analyses were performed in the central and peripheral nervous systems of myelin mutant mice. In these mice, paranodal axo-glial junctions(AGJ) were disrupted but compact myelin was preserved. The present results demonstrated that disruption of AGJ caused local axonal swellings containing various axonal components and changes of axonal transport-related molecules. Involvement of local calcium change was suggested. Focal axonal swellings were first observed at early stage of myelination and progressive with age. Axonal degeneration became more prominent in aged mice. Thus, the axo-glial interaction at the paranode is important for local axonal homeostasis.