Regional differences in the developing cerebral cortex revealed by ephrin-A5 expression
Regional differences in the developing cerebral cortex revealed by ephrin-A5 expression
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DOI：
10.1093/cercor/9.6.601
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发表时间：
1999-09-01
期刊：
影响因子：
3.7
通讯作者：
McConnell, SK
中科院分区：
文献类型：
--
作者：
Mackarehtschian, K;Lau, CK;McConnell, SK
丘脑核团和它们的皮质靶区之间的轴突连接的发展以高度特异性的方式发生。为了探讨丘脑皮质轴突寻路的机制，我们研究了前脑中ephrin和Eph基因家族的几个成员的表达。Eph配体ephrin-A5在端脑发育过程中以三种不同的梯度表达。第一个梯度发生在皮质脑室区，并建立ephrin-A5作为区分前皮质神经上皮细胞和后皮质神经上皮细胞的最早标志物之一。第二个梯度在亚板中是明显的，并且在空间上与低亲和力NGF受体p75的明显梯度相反。这一发现揭示了早期亚板的不同区域是分子异质性的。第三，我们证实ephrin-A5在皮质板中以双向梯度表达，在躯体运动皮质中具有最高的revels。肝配蛋白A5的三种推定受体-EphA 3、EphA 4和EphA 5在发育中的丘脑中表现出不同的表达模式。ephrin-A5在发育中的基板和皮质中的分级分布及其受体在丘脑中的表达与Eph配体及其受体可能在丘脑轴突到特定皮质区域的地形图绘制中起作用的概念一致。
The development of axonal connections between thalamic nuclei and their cortical target areas occurs in a highly specific manner. To explore the mechanisms of thalamocortical axon pathfinding, we investigated the expression of several members of the ephrin and Eph gene families in the forebrain. The Eph ligand ephrin-A5 was expressed in three distinct gradients during the development of the telencephalon. The first gradient occurred in the cortical Ventricular zone and established ephrin-A5 as one of the earliest markers distinguishing cells residing in the anterior Versus posterior cortical neuroepithelium. The second gradient was apparent in the subplate and occurred in spatial opposition to a distinct gradient for the low-affinity NGF receptor p75. This finding reveals that different regions of the early subplate are molecularly heterogeneous. Third, we confirmed that ephrin-A5 is expressed in a bi-directional gradient in the cortical plate, with highest revels in the somatomotor cortex. Three putative receptors far ephrin-A5 - EphA3, EphA4 and EphA5 showed distinct expression patterns in the developing thalamus. The graded distributions of ephrin-A5 in the developing subplate and cortex and the expression of its receptors in the thalamus are consistent with the notion that the Eph ligands and their receptors may function in the topographic mapping of thalamic axons to specific cortical areas.