Glutamatergic synapses on oligodendrocyte precursor cells in the hippocampus
Glutamatergic synapses on oligodendrocyte precursor cells in the hippocampus
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DOI：
10.1038/35012083
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发表时间：
2000-05-11
期刊：
影响因子：
64.8
通讯作者：
Jahr, CE
中科院分区：
文献类型：
--
作者：
Bergles, DE;Roberts, JDB;Jahr, CE
在中枢神经系统中，快速兴奋性神经传递发生在神经元之间的特殊突触连接处，在那里高浓度的谷氨酸直接激活受体通道。低亲和力AMPA （α -氨基-3-羟基-5-甲基异恶唑丙酸）和海因酸谷氨酸受体也在一些胶质细胞中表达(1)，包括少突胶质细胞前体细胞（OPCs）。然而，导致这些非神经元细胞上谷氨酸受体激活的条件尚不清楚。在这里，我们报道了海马兴奋性轴突的刺激引起由AMPA受体介导的OPCs向内电流。这些反应的量性质及其快速动力学表明，它们是由这些受体对面充满谷氨酸的囊泡的胞吐产生的。其中一些AMPA受体对钙离子具有渗透性，在轴突活性和OPCs内部钙水平之间提供了联系。电镜分析显示，在年轻和成年海马中，充满囊泡的轴突终末与OPCs过程形成突触连接。这些结果表明，在哺乳动物海马中存在一个由兴奋性谷氨酸突触介导的从锥体神经元到OPCs的快速信号通路。
Fast excitatory neurotransmission in the central nervous system occurs at specialized synaptic junctions between neurons, where a high concentration of glutamate directly activates receptor channels. Low-affinity AMPA (alpha-amino-3-hydroxy-5-methyl isoxazole propionic acid) and kainate glutamate receptors are also expressed by some glial cells(1), including oligodendrocyte precursor cells (OPCs). However, the conditions that result in activation of glutamate receptors on these non-neuronal cells are not known. Here we report that stimulation of excitatory axons in the hippocampus elicits inward currents in OPCs that are mediated by AMPA receptors. The quantal nature of these responses and their rapid kinetics indicate that they are produced by the exocytosis of vesicles filled with glutamate directly opposite these receptors. Some of these AMPA receptors are permeable to calcium ions, providing a link between axonal activity and internal calcium levels in OPCs. Electron microscopic analysis revealed that vesicle-filled axon terminals make synaptic junctions with the processes of OPCs in both the young and adult hippocampus. These results demonstrate the existence of a rapid signalling pathway from pyramidal neurons to OPCs in the mammalian hippocampus that is mediated by excitatory, glutamatergic synapses.