Excitability and synaptic communication within the oligodendrocyte lineage.
Excitability and synaptic communication within the oligodendrocyte lineage.
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DOI：
10.1523/jneurosci.6000-09.2010
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发表时间：
2010-03-10
期刊：
影响因子：
--
通讯作者：
Bergles DE
中科院分区：
文献类型：
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作者：
De Biase LM;Nishiyama A;Bergles DE
哺乳动物中枢神经系统含有丰富的，广泛分布的神经胶质细胞，作为少突胶质细胞祖细胞。据报道，这些NG 2-免疫反应细胞（NG 2+细胞）形成突触并产生动作电位，这表明这些祖细胞的神经诱发的兴奋可能调节少突胶质细胞的发生。然而，最近的研究还表明，NG 2+细胞由功能不同的组组成，其对神经元活性的反应能力不同，经历分化，并经历缺血后的损伤。为了更好地定义NG 2+细胞的生理特性，我们使用了转基因小鼠，其允许对该群体进行无偏采样并明确识别处于离散分化状态的细胞。使用从发育和成熟小鼠制备的急性脑切片，我们发现不同脑区的NG 2+细胞共享一组核心生理特性，包括电压门控Na+（NaV）通道和离子型谷氨酸受体的表达，以及与谷氨酸能神经元形成突触。虽然小振幅的Na+峰可以引起一些NG 2+细胞在出生后的第一周，他们不能产生动作电位。这些祖细胞向髓鞘形成前阶段的过渡伴随着突触输入的快速去除，以及AMPA和NMDA受体和NaV通道的下调。因此，先前关于NG 2+细胞之间生理异质性的报道可能反映了对成熟后期细胞的分析。这些结果表明，NG 2+细胞在少突胶质细胞谱系中具有独特的位置，以监测周围神经元的放电模式。
The mammalian CNS contains an abundant, widely distributed population of glial cells that serve as oligodendrocyte progenitors. It has been reported that these NG2-immunoreactive cells (NG2+ cells) form synapses and generate action potentials, suggesting that neural-evoked excitation of these progenitors may regulate oligodendrogenesis. However, recent studies also suggest that NG2+ cells are comprised of functionally distinct groups that differ in their ability to respond to neuronal activity, undergo differentiation, and experience injury following ischemia. To better define the physiological properties of NG2+ cells, we used transgenic mice that allowed an unbiased sampling of this population and unambiguous identification of cells in discrete states of differentiation. Using acute brain slices prepared from developing and mature mice, we found that NG2+ cells in diverse brain regions share a core set of physiological properties, including expression of voltage-gated Na+ (NaV) channels and ionotropic glutamate receptors, and formation of synapses with glutamatergic neurons. Although small amplitude Na+ spikes could be elicited in some NG2+ cells during the first postnatal week, they were not capable of generating action potentials. Transition of these progenitors to the pre-myelinating stage was accompanied by the rapid removal of synaptic input, as well as down regulation of AMPA and NMDA receptors and NaV channels. Thus, prior reports of physiological heterogeneity among NG2+ cells may reflect analysis of cells in later stages of maturation. These results suggest that NG2+ cells are uniquely positioned within the oligodendrocyte lineage to monitor the firing patterns of surrounding neurons.