High-concentration rapid transients of glutamate mediate neural-glial communication via ectopic release
High-concentration rapid transients of glutamate mediate neural-glial communication via ectopic release
复制标题
DOI：
10.1523/jneurosci.1927-05.2005
复制
发表时间：
2005-08-17
影响因子：
5.3
通讯作者：
Rubio, ME
中科院分区：
文献类型：
--
作者：
Matsui, K;Jahr, CE;Rubio, ME
直到最近，从神经元到星形胶质细胞的通信被认为是由突触间隙溢出引起的低浓度谷氨酸瞬变介导的。然而，大鼠小脑Bergmann胶质细胞（BG）记录的量子事件具有快速的动力学，与神经元中记录的量子事件相当。通过结合外向补丁记录BG AMPA受体和定量电子显微镜分析谷氨酸受体亚基1（GluR 1）和GluR 4免疫金标记测量，在索马和突触周围的膜，我们估计的绝对密度的功能AMPA受体。使用BG AMPA受体的动力学模型，我们发现记录在BG中的量子事件是由谷氨酸的高浓度（类似于1-1.5 mM）、快速瞬变（类似于0.5 ms衰减）产生的，类似于突触间隙内的瞬变。我们的研究结果表明，神经信号BG介导的异位释放的递质从突触前元件直接面对BG膜。
Until recently, communication from neurons to astrocytes was thought to be mediated by low-concentration transients of glutamate caused by spillover from the synaptic cleft. However, quantal events recorded in rat cerebellar Bergmann glial cells (BGs) have fast kinetics, comparable with those recorded in neurons. By combining outside-out patch recordings of BG AMPA receptors and quantitative electron microscopic analysis of glutamate receptor subunit 1 (GluR1) and GluR4 immunogold labeling measurements, at both the soma and membranes surrounding synapses, we estimate the absolute density of functional AMPA receptors. Using a kinetic model of BG AMPA receptors, we find that quantal events recorded in BGs are produced by high-concentration (similar to 1-1.5 mM), fast transients (similar to 0.5 ms decay) of glutamate, similar to transients within the synaptic cleft. Our results indicate that neural signaling to BGs is mediated by ectopic release of transmitter from presynaptic elements directly facing the BG membrane.