MRC Centre for Developmental Neurobiology, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK.
Semin Cell Dev Biol. 2012 Feb;23(1):1-6. doi: 10.1016/j.semcdb.2011.10.015. Epub 2011 Oct 21.
In the classical view of axon guidance, neurons send out axons which are endowed with guidance receptors enabling them to find their (distant) target areas by an interaction with their ligands expressed in specific spatio-temporal patterns along their pathways and in their target area. However, this view has recently been confounded by more detailed analyses of, for example, the expression patterns of EphAs and ephrinAs in the retinotectal projection. Here ephrinA 'ligands' are expressed not only in the target area but also on the projecting RGC axons, and EphA 'receptors' not only on retinal ganglion cell (RGC) axons but also in the target area itself. This review describes the on-going functional characterisation of the surprising co-expression of ephrinAs and EphAs on retinal ganglion cell (RGC) axons and other cell types. It also investigates the function of ephrinAs as receptors and describes their interaction with co-receptors involved in mediating this function.
在经典的轴突导向观点中，神经元发出轴突，这些轴突被赋予导向受体，使它们能够通过与沿其路径和在目标区域中以特定时空模式表达的配体相互作用来找到它们的（遥远）靶区。然而，最近对例如视网膜-顶盖投射中 EphAs 和 ephrinAs 的表达模式的更详细分析使这种观点变得复杂。在这里， EphrinA“配体”不仅在靶区表达，而且在投射的 RGC 轴突上表达，而 EphA“受体”不仅在视网膜神经节细胞（RGC）轴突上表达，而且在靶区本身也表达。这篇综述描述了 EphrinAs 和 EphAs 在视网膜神经节细胞（RGC）轴突和其他细胞类型上令人惊讶的共表达的正在进行的功能特征。它还研究了 EphrinAs 作为受体的功能，并描述了它们与参与介导此功能的共受体的相互作用。
