Early events of peripheral nerve regeneration
Early events of peripheral nerve regeneration
复制标题
DOI：
10.1017/s1740925x05000347
复制
发表时间：
2006-01-01
影响因子：
--
通讯作者：
Zochodne, Douglas
中科院分区：
文献类型：
--
作者：
Mcdonald, David;Cheng, Chu;Zochodne, Douglas
受损周围神经的早期再生涉及一系列事件，这些事件对于最终重新连接的成功至关重要。在许多神经损伤中，例如具有间隙的横断，轴突和雪旺细胞（SC）渗透到新的微环境中，而不涉及沃勒变性区。我们研究了未开发的轴突SC的相互作用采样新形成的连接，通过硅胶导管横跨横断大鼠坐骨周围神经间隙。通过光学显微镜、电子显微镜和双标记免疫组织化学（包括共聚焦成像）研究了轴突和SC参与桥形成的情况，并确定了几个不太受重视的早期再生方面。轴突和SC早期和广泛再生为最初由结缔组织和血管形成的桥存在局限性。再生是“交错”的，只有一小部分的父轴突采样早期的桥梁。SC和轴突的延伸之间存在着密切的、几乎不变的关系，这挑战了轴突引导和SC跟随的概念。“裸”轴突是罕见的，范围有限。轴突没有寻求和坚持血管层粘连蛋白，但密切关注层粘连蛋白沉积与并列的SC。通过标记β III微管蛋白、PGP（9.5）和GAP（43/）B（50）鉴定的生长锥是复杂的，这意味着它们的再生长暂停，并且在近端残端-再生桥界面处最突出。对于轴突局部再生为新形成的周围神经桥，存在着令人惊讶的和实质性的敌意。早期轴突生长，与并置的雪旺氏细胞过程，是高度限制，即使没有暴露于相邻的髓鞘和沃勒变性的产品。
Early regeneration of injured peripheral nerves involves a series of events that are important in the success of eventual reconnection. In many nerve injuries, such as transections with gaps, axons and Schwann cells (SCs) penetrate into new microenvironments de nova, not involving zones of Wallerian degeneration. We studied unexplored axon-SC interactions by sampling of newly forming connections through a silicone conduit across transected rat sciatic peripheral nerve gaps. Axon and SC-participation in bridge formation was addressed by light microscopy, electron microscopy and by double-labeling immunohistochemistry, including confocal imaging, and several, less appreciated aspects of early regrowth were identified. There are limitations to early and widespread regeneration of axons and SCs into bridges initially formed from connective tissue and blood vessels. Regrowth is 'staggered' such that only a small percentage of parent axons sampled the early bridge. There is an intimate, almost invariable relationship between SCs and extension of axons, which challenges the concept that axons lead and SCs follow. 'Naked' axons were infrequent and limited in scope. Axons did not seek out and adhere to vascular laminin but intimately followed laminin deposits associated with apposed SCs. Growth cones identified by labeling of beta III tubulin, PGP(9.5) and GAP(43/)B(50) were complex, implying a pause in their regrowth, and were most prominent at the proximal stump-regenerative bridge interface. There is surprising and substantial hostility to local regrowth of axons into newly forming peripheral nerve bridges. Early axon outgrowth, associated with apposed Schwann cell processes, is highly constrained even when not exposed to adjacent myelin and products of Wallerian degeneration.