Stereotyped axon pruning via plexin signaling is associated with synaptic complex elimination in the hippocampus
Stereotyped axon pruning via plexin signaling is associated with synaptic complex elimination in the hippocampus
复制标题
通过丛神经信号传导的定型轴突修剪与海马突触复合体的消除有关
DOI：
10.1523/jneurosci.2648-05.2005
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发表时间：
2005-10-05
影响因子：
5.3
通讯作者：
Cheng, HJ
中科院分区：
文献类型：
--
作者：
Liu, XB;Low, LK;Cheng, HJ
脊椎动物中枢神经系统中长轴突侧支的定型修剪需要丛蛋白信号传导；然而，丛蛋白对定型修剪的细胞基础尚未确定。利用定量电子显微镜和免疫细胞化学，我们发现锥体下苔藓纤维轴突侧支与出生后早期小鼠海马 CA3 锥体细胞的基底树突形成瞬时突触复合物。在出生后的后期，这些突触复合体停止成熟，并在定型修剪之前通过不涉及轴突变性和神经胶质细胞吞噬的机制被去除。在缺乏 plexin-A3 信号传导的基因敲除小鼠中，突触复合体继续成熟，因此侧枝循环不会被修剪。因此，我们的结果表明，完整的 plexin-A3 信号传导有助于突触复合体的消除，这与刻板的轴突修剪有关。
Plexin signaling is required for stereotyped pruning of long axon collaterals in the vertebrate CNS; however, a cellular basis for plexins on stereotyped pruning has not been determined. Using quantitative electron microscopy and immunocytochemistry, we found that infra-pyramidal mossy fiber axon collaterals form transient synaptic complexes with basal dendrites of CA3 pyramidal cells in the early postnatal mouse hippocampus. At later postnatal ages, these synaptic complexes stop maturing and are removed before stereotyped pruning by a mechanism that does not involve axon degeneration and glial cell engulfment. In knock-out mice that lack plexin-A3 signaling, the synaptic complexes continue to mature, and, as a result, the collaterals are not pruned. Thus, our results suggest that intact plexin-A3 signaling contributes to synaptic complex elimination, which is associated with stereotyped axon pruning.