Pre-synaptic and post-synaptic localization of EphA4 and EphB2 in adult mouse forebrain
Pre-synaptic and post-synaptic localization of EphA4 and EphB2 in adult mouse forebrain
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DOI：
10.1111/j.1471-4159.2008.05416.x
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发表时间：
2008-07-01
影响因子：
4.7
通讯作者：
Doucet, Guy
中科院分区：
文献类型：
--
作者：
Bouvier, David;Corera, Amadou T.;Doucet, Guy
肝配蛋白受体EphA 4和EphB 2与大脑皮层和海马中的突触发生和长时程增强有关，在那里它们通常被视为突触后受体。为了确定EphA 4和EphB 2在成熟脑突触中的精确分布，我们使用亚细胞分离和电子显微镜检查成年小鼠前脑/中脑。EphA 4和EphB 2都富集在微粒体和突触体中。在突触体中，它们存在于膜和突触囊泡组分中。虽然EphA 4与富含PSD-95的突触后密度级分紧密相关，但EphB 2易于用去污剂提取。相反，这两种受体被发现在突触前活性区部分。通过电子显微镜，EphA 4主要在轴突末端检测到，而EphB 2更频繁地检测到在大的树突轴，在海马和大脑皮层。然而，在丘脑腹侧基底，EphB 2检测最频繁的轴突终端和薄树突轴。EphA 4和EphB 2在神经元和突触连接的多个隔室中的定位表明它们与几种不同的支架蛋白相互作用，并在突触中发挥不同的作用。
The ephrin receptors EphA4 and EphB2 have been implicated in synaptogenesis and long-term potentiation in the cerebral cortex and hippocampus, where they are generally viewed as post-synaptic receptors. To determine the precise distribution of EphA4 and EphB2 in mature brain synapses, we used subcellular fractionation and electron microscopy to examine the adult mouse forebrain/midbrain. EphA4 and EphB2 were both enriched in microsomes and synaptosomes. In synaptosomes, they were present in the membrane and the synaptic vesicle fractions. While EphA4 was tightly associated with PSD-95-enriched post-synaptic density fractions, EphB2 was easily extracted with detergents. In contrast, both receptors were found in the pre-synaptic active zone fraction. By electron microscopy, EphA4 was mainly detected in axon terminals, whereas EphB2 was more frequently detected in large dendritic shafts, in the hippocampus and cerebral cortex. However, in the ventrobasal thalamus, EphB2 was detected most frequently in axon terminals and thin dendritic shafts. The localization of EphA4 and EphB2 in multiple compartments of neurons and synaptic junctions suggests that they interact with several distinct scaffolding proteins and play diverse roles at synapses.