Time constraints and positional cues in the developing cerebellum regulate Purkinje cell placement in the cortical architecture
Time constraints and positional cues in the developing cerebellum regulate Purkinje cell placement in the cortical architecture
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DOI：
10.1016/j.ydbio.2008.02.005
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发表时间：
2008-05-01
影响因子：
2.7
通讯作者：
Rossi, Ferdinando
中科院分区：
文献类型：
--
作者：
Carletti, Barbara;Williams, Ian Martin;Rossi, Ferdinando
为了阐明调节小脑回路中神经元放置和整合的机制，我们评估了移植到胚胎、青少年和成年宿主的浦肯野细胞的命运，询问发育中皮层的结构变化如何影响它们的解剖整合。供体浦肯野细胞沿着其自然迁移路径或沿着不寻常的路线穿过宿主实质。在后一种情况下，供体神经元无法正确定向并建立皮质核投射。遵循生理途径的浦肯野细胞实现了典型的定向和连接，但如果它们到达受体皮层的时间被延迟，则最终会在分子层中移位。供体神经元的导航路线和最终定居随着宿主年龄的不同而变化，这取决于皮质分层的个体发育结构，特别是颗粒细胞的成熟。外部颗粒层消融或颗粒细胞产生的 reelin 信号中和后，移植的浦肯野细胞的迁移行为和归巢发生了改变。因此，尽管小脑环境即使在发育结束后仍能接受浦肯野细胞，但供体神经元的正确放置取决于它们迁移的时间，与小脑发育动力学和颗粒细胞分层有关。 (C) 2008 Elsevier Inc. 保留所有权利。
To elucidate the mechanisms that regulate neuronal placement and integration in the cerebellar circuitry, we assessed the fate of Purkinje cells transplanted to embryonic, juvenile and adult hosts, asking how architectural changes of the developing cortex influence their anatomical incorporation. Donor Purkinje cells navigate through the host parenchyma either along their natural migratory pathway or following unusual routes. In the latter case, donor neurons fail to orientate correctly and to establish the cortico-nuclear projection. Purkinje cells that follow the physiological route achieve the typical orientation and connectivity, but end displaced in the molecular layer if their arrival in the recipient cortex is delayed. Navigation routes and final settling of donor neurons vary with host age, depending on the ontogenetic construction of cortical layering, and particularly on the maturation of granule cells. The migratory behavior and homing of transplanted Purkinje cells is modified after external granular layer ablation, or neutralization of reelin signaling produced by granule cells. Therefore, although the cerebellar milieu remains receptive for Purkinje cells even after the end of development, correct placement of donor neurons depends on the timing of their migration, related to cerebellar developmental dynamics and granule cell layering. (C) 2008 Elsevier Inc. All rights reserved.