SPECIFICITY OF CELL CELL COUPLING IN RAT OPTIC-NERVE ASTROCYTES INVITRO
SPECIFICITY OF CELL CELL COUPLING IN RAT OPTIC-NERVE ASTROCYTES INVITRO
复制标题
DOI：
10.1073/pnas.87.24.9833
复制
发表时间：
1990-12-01
影响因子：
11.1
通讯作者：
RANSOM, BR
中科院分区：
文献类型：
--
作者：
SONTHEIMER, H;MINTURN, JE;RANSOM, BR
用A2B5抗体染色研究培养的大鼠视神经星形胶质细胞的细胞间偶联。通过向单个细胞注射低分子量荧光染料荧光黄并注意到染料进入相邻细胞来评估细胞耦合的存在；通过使用全细胞膜片钳记录分析响应小电压阶跃而记录的电流瞬变的衰变阶段来研究细胞耦合。细胞偶联仅限于A2B5-星形胶质细胞，大部分有扁平的成纤维细胞样出现，在A2B5+星形细胞中从未观察到。此外，A2B5-星形胶质细胞仅与A2B5-星形胶质细胞偶联，而不与A2B5+星形胶质细胞偶联。对电流瞬变的分析为电池耦合提供了一个额外的指标。表现出染料偶联到至少一个相邻细胞的星形胶质细胞需要两个指数函数的和来拟合电流瞬变，而在没有染料偶联的细胞中，单个指数函数足以拟合瞬变。培养的大鼠视神经星形胶质细胞的细胞偶联的特异性表明，主要是A2B5-星形胶质细胞组成了一个耦合的胶质合胞体；这些细胞的这一生理特征可能是对“空间缓冲”的一种特殊适应，即K+从局灶性细胞外积聚的区域转移出去。另一方面，A2B5+星形胶质细胞形成一个非偶联的大鼠视神经胶质细胞亚群，可能具有不同的功能。
Intercellular coupling was studied in cultured rat optic nerve astrocytes individually characterized by A2B5 antibody staining. The presence of cell coupling was assessed by injecting single cells with the low molecular weight fluorescent dye Lucifer yellow and noting dye passage into adjacent cells; cell coupling was also studied by analyzing the decay phase of current transients recorded in response to small voltage steps using whole-cell patch-clamp recording. Cell coupling was restricted to A2B5- astrocytes, the majority of which had a flat fibroblast-like appeared and was never observed in A2B5+ stellate-shaped astrocytes. Furthermore, A2B5- astrocytes showed coupling only to A2B5- and never to A2B5+ astrocytes. Analysis of current transients provided an additional indicator for cell coupling. Astrocytes that showed dye coupling to at least one neighboring cell required the sum of two exponential functions to fit current transients, whereas a single exponential function sufficed to fit transients in cells that were not dye coupled. The specificity of cell coupling in cultured rat optic nerve astrocytes suggests that predominantly A2B5- astrocytes comprise a coupled glial syncytium; this physiological feature of these cells may be a specialized adaptation for "spatial buffering," the transport of K+ away from areas of focal extracellular accumulation. On the other hand, A2B5+ astrocytes form an uncoupled subpopulation of rat optic nerve glial cells that may serve different functions.