Topographic guidance labels in a sensory projection to the forebrain
Topographic guidance labels in a sensory projection to the forebrain
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DOI：
10.1016/s0896-6273(00)80650-9
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发表时间：
1998-12-01
期刊：
影响因子：
16.2
通讯作者：
Flanagan, JG
中科院分区：
文献类型：
--
作者：
Feldheim, DA;Vanderhaeghen, P;Flanagan, JG
已知哺乳动物前脑的视觉连接是由神经活动形成的，但尚不清楚这种高级感觉投射的地图地形是否取决于轴突引导标签。在这里，我们展示了EphA5受体在小鼠视网膜及其配体ephrin-A2和ephrin-A5在多个视网膜靶点的互补表达和结合，包括主要的前脑靶点，背外侧膝状核（dLGN）。这些配体在体外可以作为哺乳动物视网膜轴突的地形特异性驱虫剂，并且是正常dLGN在体内定位所必需的。结果表明，通过重复使用相同的标签，将一个投射场映射到多个目标上，这是一种通用的、经济的大脑映射模块化机制。它们还表明了将感觉连接映射到前脑的坐标系统的本质。
Visual connections to the mammalian forebrain are known to be patterned by neural activity, but it remains unknown whether the map topography of such higher sensory projections depends on axon guidance labels. Here, we show complementary expression and binding for the receptor EphA5 in mouse retina and its ligands ephrin-A2 and ephrin-A5 in multiple retinal targets, including the major forebrain target, the dorsal lateral geniculate nucleus (dLGN). These ligands can act in vitro as topographically specific repellents for mammalian retinal axons and are necessary for normal dLGN mapping in vivo. The results suggest a general and economic modular mechanism for brain mapping whereby a projecting field is mapped onto multiple targets by repeated use of the same labels. They also indicate the nature of a coordinate system for the mapping of sensory connections to the forebrain.