Ephrin-A5 modulates the topographic mapping and connectivity of commissural axons in murine hippocampus
Ephrin-A5 modulates the topographic mapping and connectivity of commissural axons in murine hippocampus
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DOI：
10.1016/j.neuroscience.2006.03.052
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发表时间：
2006-01-01
期刊：
影响因子：
3.3
通讯作者：
Martinez, A.
中科院分区：
文献类型：
--
作者：
Otal, R.;Burgaya, F.;Martinez, A.
内嗅和连合/联合投影显示海马体和齿状回的非重叠分布。 Ephrins 及其 Eph 受体在发育中的海马体中的表达表明该轴突引导分子家族可能调节这些连接的形成。在这里，我们重点关注肝配蛋白 A5 配体在主要海马传入神经发育中的作用。原位杂交显示，在整个出生后发育过程中，ephrin-A5 mRNA 主要在海马本身的主细胞和齿状回中检测到。免疫细胞化学分析显示，EphA3 受体（肝配蛋白 A5 的推定受体）在发育中海马的主要细胞和神经毡中显着表达。肝配蛋白-A5(-/-)小鼠的示踪实验表明，海马体的连合投射在P5时发生了短暂改变，但在齿状回的出生后发育过程中它们的定位是错误的。抗钙结合蛋白抗体的免疫细胞化学显示，肝配蛋白-A5(-/-)小鼠的齿状苔藓纤维投射没有改变。电子显微镜研究显示，这些动物的连合层/联合层的突触和棘的密度发生了变化，但内嗅层和苔藓纤维中的突触和棘密度没有变化。综上所述，这些发现表明肝配蛋白 A5 信号传导参与海马突触的形成和成熟。 (c) 2006 年国际广播组织。由爱思唯尔有限公司出版。保留所有权利。
Entorhinal and commissural/associational projections show a non-overlapping distribution in the hippocampus proper and the dentate gyrus. The expression of Ephrins and their Eph receptors in the developing hippocampus indicates that this family of axonal guidance molecules may modulate the formation of these connections. Here we focused on the role of the ephrin-A5 ligand in the development of the main hippocampal afferents. In situ hybridization showed that ephrin-A5 mRNA was detected mainly in the principal cells of the hippocampus proper and in the dentate gyrus throughout postnatal development. Immunocytochemical analyses revealed prominent expression of the EphA3 receptor, a putative receptor for ephrin-A5, in the main cells and the neuropil of the developing hippocampus. Tracing experiments in ephrin-A5(-/-) mice showed that commissural projections were transiently altered in the hippocampus proper at P5, but they were mistargeted throughout the postnatal development in the dentate gyrus.Immunocytochemistry with anti-calbindin antibodies revealed that the dentate mossy fiber projection was not altered in ephrin-A5(-/-) mice. Electron microscopy studies showed alterations in the density of synapses and spines in commissural/associational layers, but not in entorhinal layers, and in the mossy fibers in these animals. Taken together, these findings indicate that ephrin-A5 signaling is involved in the formation and maturation of synapses in the hippocampus. (c) 2006 IBRO. Published by Elsevier Ltd. All rights reserved.