Tangential networks of precocious neurons and early axonal outgrowth in the embryonic human forebrain
Tangential networks of precocious neurons and early axonal outgrowth in the embryonic human forebrain
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DOI：
10.1523/jneurosci.4770-04.2005
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发表时间：
2005-03-16
影响因子：
5.3
通讯作者：
Blakemore, C
中科院分区：
文献类型：
--
作者：
Bystron, I;Molnár, Z;Blakemore, C
我们采用免疫组织化学和碳青素染色示踪相结合的方法，研究了受孕后4-7周、突触发生前的人胚胎前脑神经元及其过程。在皮质板出现和丘脑皮质连接建立之前，我们发现了一个广泛的早熟MAP2（微管相关蛋白2）免疫反应细胞网络，具有长而非轴突的过程。染料示踪显示，这些早熟细胞的过程在丘脑、神经节隆起、下丘脑和皮质前板的中间区域之间形成切向联系。皮层前板中早熟神经元的时空分布和形态表明它们是在脑壁外产生的，而不是在局部心室区。在第一个皮质板神经元到达之前，第一个丘脑皮质轴突和前板细胞的轴突跨越间脑-端脑和纹状皮质边界。早熟细胞可能提供了胚胎脑各分支之间的初始通信，以及为生长的轴突导航和/或横向神经元迁移提供了指导线索。
We used a combination of immunohistochemistry and carbocyanine dye tracing to study neurons and their processes in the human embryonic forebrain, 4-7 weeks after conception, before the onset of synaptogenesis. We discovered a widespread network of precocious MAP2 (microtubule-associated protein 2)-immunoreactive cells, with long, nonaxonal processes, before the appearance of the cortical plate and the establishment of thalamocortical connectivity. Dye tracing revealed that the processes of these precocious cells form tangential links between intermediate zones of the thalamus, ganglionic eminence, hypothalamus, and cortical preplate. The spatiotemporal distribution and morphology of the precocious neurons in the cortical preplate suggest that they are generated outside the cerebral wall rather than in the local ventricular zone. The first thalamocortical axons and axons of preplate cells extend across diencephalo-telencephalic and striatocortical boundaries before the arrival of the first cortical plate neurons. Precocious cells may provide initial communication between subdivisions of the embryonic brain as well as guidance cues for navigation of growing axons and/or transverse neuronal migration.