Gray matter NG2 cells display multiple Ca2+-signaling pathways and highly motile processes.
Gray matter NG2 cells display multiple Ca2+-signaling pathways and highly motile processes.
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DOI：
10.1371/journal.pone.0017575
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发表时间：
2011-03-24
期刊：
影响因子：
3.7
通讯作者：
Jabs R
中科院分区：
文献类型：
--
作者：
Haberlandt C;Derouiche A;Wyczynski A;Haseleu J;Pohle J;Karram K;Trotter J;Seifert G;Frotscher M;Steinhäuser C;Jabs R
NG 2细胞是哺乳动物中枢神经系统中的第四种神经胶质细胞，接受来自神经元的突触输入。这种神经支配的功能尚不清楚。突触后细胞内Ca ~（2+）浓度（[Ca ~（2+）]i）的变化可能是其结果。我们采用荧光标记NG 2细胞的转基因小鼠来解决这个问题。为了确定Ca 2+信号通路，我们结合了膜片钳记录，Ca 2+成像，mRNA转录分析和各种物质的局部压力应用，以确定急性海马切片中的NG 2-细胞。我们发现，激活电压门控钙通道，钙渗透AMPA受体，和组I代谢型谷氨酸受体引起[Ca 2 +] i-升高NG 2细胞。Ca 2+内流通过Ca 2+诱导的Ca 2+释放而放大。最小的电刺激突触前神经元引起突触后电流，但没有体细胞[Ca 2 +]i升高，这表明[Ca 2 +]i升高NG 2细胞可能仅限于他们的过程。局部Ca 2+信号可能会引发递质释放或细胞运动性的变化。为了确定这种情况下的结构先决条件，我们使用电子显微镜，免疫染色，mRNA转录分析，和时间推移成像。我们发现NG 2细胞与突触前神经元形成对称和不对称突触，并显示囊泡谷氨酸转运体1的免疫反应性。突起以肌动蛋白为基础，含有埃兹蛋白，但不含胶质纤维、微管或内质网。此外，我们证明原位NG 2细胞突起具有高度运动性。我们的研究结果表明，灰质NG 2细胞被赋予与相邻细胞双向通信的细胞机制。
NG2 cells, the fourth type of glia in the mammalian CNS, receive synaptic input from neurons. The function of this innervation is unknown yet. Postsynaptic changes in intracellular Ca2+-concentration ([Ca2+]i) might be a possible consequence. We employed transgenic mice with fluorescently labeled NG2 cells to address this issue. To identify Ca2+-signaling pathways we combined patch-clamp recordings, Ca2+-imaging, mRNA-transcript analysis and focal pressure-application of various substances to identified NG2-cells in acute hippocampal slices. We show that activation of voltage-gated Ca2+-channels, Ca2+-permeable AMPA-receptors, and group I metabotropic glutamate-receptors provoke [Ca2+]i-elevations in NG2 cells. The Ca2+-influx is amplified by Ca2+-induced Ca2+-release. Minimal electrical stimulation of presynaptic neurons caused postsynaptic currents but no somatic [Ca2+]i elevations, suggesting that [Ca2+]i elevations in NG2 cells might be restricted to their processes. Local Ca2+-signaling might provoke transmitter release or changes in cell motility. To identify structural prerequisites for such a scenario, we used electron microscopy, immunostaining, mRNA-transcript analysis, and time lapse imaging. We found that NG2 cells form symmetric and asymmetric synapses with presynaptic neurons and show immunoreactivity for vesicular glutamate transporter 1. The processes are actin-based, contain ezrin but not glial filaments, microtubules or endoplasmic reticulum. Furthermore, we demonstrate that NG2 cell processes in situ are highly motile. Our findings demonstrate that gray matter NG2 cells are endowed with the cellular machinery for two-way communication with neighboring cells.