The L1 cell adhesion molecule is essential for topographic mapping of retinal axons
The L1 cell adhesion molecule is essential for topographic mapping of retinal axons
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DOI：
10.1523/jneurosci.23-02-00530.2003
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发表时间：
2003-01-15
影响因子：
5.3
通讯作者：
Maness, PF
中科院分区：
文献类型：
--
作者：
Demyanenko, GP;Maness, PF
视网膜丘投射是研究哺乳动物中枢神经系统突触靶向分子机制的首选轴突导向通路。在这里，我们确定了以前未被认识到的作用，L1细胞粘附分子在视网膜神经节细胞（RGC）轴突的地形图在小鼠上级丘（SC）的目标。L1在轴突生长和定位过程中在RGC轴突上瞬时表达。视网膜轴突的DiI标记显示，L1-minus小鼠的颞侧轴突绕过了前SC中的正确目标位置，在不正确的后部部位形成终止区，这些部位通常沿沿着中外侧轴偏斜。在发展过程中的retinotopic mapL 1-减颞轴突延伸穿过前后轴的SC像野生型轴突，但未能arborize在正常的前目标网站。L1-负RGC轴突表现出正常的交叉在视交叉和视神经束。结果表明，视网膜轴突需要L1的功能，除了排斥EphA指导受体，以实现适当的地形图。
The retinocollicular projection is a preferred axon guidance pathway for investigating molecular mechanisms of synaptic targeting in the mammalian CNS. Here we identify a previously unrecognized role of the L1 cell adhesion molecule in topographic mapping of retinal ganglion cell (RGC) axons to their targets in the mouse superior colliculus (SC). L1 was transiently expressed on RGC axons during axon growth and targeting. DiI labeling of retinal axons revealed that temporal axons of L1-minus mice bypassed correct target locations in the anterior SC, forming termination zones at incorrect posterior sites, which were often skewed along the mediolateral axis. During development of the retinotopic mapL1-minus temporal axons extended across the anteroposterior axis of the SC like wild-type axons but failed to arborize at normal anterior target sites. L1-minus RGC axons exhibited normal crossing at the optic chiasm and fasciculation of the optic nerve. Results suggest that retinal axons require the function of L1 in addition to repellent EphA guidance receptors to achieve proper topographic mapping.