Reelin promotes neuronal orientation and dendritogenesis during preplate splitting.
Reelin promotes neuronal orientation and dendritogenesis during preplate splitting.
复制标题
DOI：
10.1093/cercor/bhp303
复制
发表时间：
2010-09
期刊：
影响因子：
3.7
通讯作者：
A. Nichols;E. Olson
中科院分区：
文献类型：
--
作者：
A. Nichols;E. Olson
分泌的配体Reelin被认为可以调节前体第6层（L6）神经元的移位和定位到预板，预板是覆盖在心室区的神经元丛。我们检查了野生型和缺乏reelin的皮质，发现在板前分裂和初始皮质板（CP）形成期间，L6神经元在pia下的位置相同。在这个发育时间点，“卷轴”皮层中没有可检测到的L6异位，这表明在预板分裂过程中，reelin信号传导可能不会调节L6神经元的迁移或总体定位。为了探讨L6神经元对Reelin的急性反应，我们向缺乏Reelin的外植体下注射Reelin。Reelin注射使L6神经元的细胞核向pia方向定向，高尔基体向pia方向极化，同时在4小时内启动旺盛的树突（MAP2+）生长。这种快速的依赖Reelin的神经元定向和排列产生了cp样的组织学，而L6神经元群体的平均位置没有明显变化。相反，注射后，基底细胞和硫酸软骨素蛋白多糖的免疫反应性在距基底表面较深的位置，表明Reelin在4小时内部分地恢复了板前分裂。因此，Reelin在板前分裂过程中促进L6神经元的快速形态分化和定向有直接作用。
The secreted ligand Reelin is thought to regulate the translocation and positioning of prospective layer 6 (L6) neurons into the preplate, a plexus of neurons overlying the ventricular zone. We examined wild type and Reelin-deficient cortices and found that L6 neurons were equivalently positioned beneath the pia during the period of preplate splitting and initial cortical plate (CP) formation. The absence of detectable L6 ectopia in "reeler" cortices at this developmental time point indicates that Reelin-signaling might not regulate L6 neuron migration or gross positioning during preplate splitting. To explore the acute response of L6 neurons to Reelin, subpial injections of Reelin were made into Reelin-deficient explants. Reelin injection caused L6 neurons to orient their nuclei and polarize their Golgi toward the pia while initiating exuberant dendritic (MAP2+) outgrowth within 4 h. This rapid Reelin-dependent neuronal orientation and alignment created CP-like histology without any significant change in the mean position of the population of L6 neurons. Conversely, subplate cells and chondroitin sulfate proteoglycan immunoreactivity were found at significantly deeper positions from the pial surface after injection, suggesting that Reelin partially rescues preplate splitting within 4 h. Thus, Reelin has a direct role in promoting rapid morphological differentation and orientation of L6 neurons during preplate splitting.