Gao P P, Yue Y, Cerretti D P, Dreyfus C, Zhou R
Laboratory for Cancer Research, Department of Chemical Biology, College of Pharmacy, Rutgers University, Piscataway, NJ 08854, USA.
Proc Natl Acad Sci U S A. 1999 Mar 30;96(7):4073-7. doi: 10.1073/pnas.96.7.4073.
Neuronal connections are arranged topographically such that the spatial organization of neurons is preserved by their termini in the targets. During the development of topographic projections, axons initially explore areas much wider than the final targets, and mistargeted axons are pruned later. The molecules regulating these processes are not known. We report here that the ligands of the Eph family tyrosine kinase receptors may regulate both the initial outgrowth and the subsequent pruning of axons. In the presence of ephrins, the outgrowth and branching of the receptor-positive hippocampal axons are enhanced. However, these axons are induced later to degenerate. These observations suggest that the ephrins and their receptors may regulate topographic map formation by stimulating axonal arborization and by pruning mistargeted axons.
神经元连接呈拓扑排列，使得神经元的空间组织通过其在靶标的终末得以保留。在拓扑投射的发育过程中，轴突最初探索的区域比最终靶标要宽得多，之后错误靶向的轴突会被修剪。调节这些过程的分子尚不清楚。我们在此报告，Eph家族酪氨酸激酶受体的配体可能同时调节轴突的初始生长和随后的修剪。在有ephrin存在的情况下，受体阳性的海马轴突的生长和分支会增强。然而，这些轴突随后会被诱导退化。这些观察结果表明，ephrin及其受体可能通过刺激轴突分支和修剪错误靶向的轴突来调节拓扑图谱的形成。
