...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >Isolation of glutamate transport-coupled charge flux and estimation of glutamate uptake at the climbing fiber-Purkinje cell synapse
【24h】

Isolation of glutamate transport-coupled charge flux and estimation of glutamate uptake at the climbing fiber-Purkinje cell synapse

机译：谷氨酸转运耦合电荷通量的分离和在攀登纤维-Purkinje细胞突触处谷氨酸吸收的估计

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Excitatory amino acid transporters (EAATs) located on neurons and glia are responsible for limiting extracellular glutamate concentrations, but specific contributions made by neuronal and glial EAATs have not been determined. At climbing fiber to Purkinje cell (PC) synapses in cerebellum, a fraction of released glutamate is rapidly bound and inactivated by neuronal EAATs located on postsynaptic PCs. Because transport involves a stoichiometric movement of ions and is electrogenic, postsynaptic currents mediated by EAATs should permit precise calculation of the amount of postsynaptic glutamate uptake. However, this is possible only if a stoichiometric EAAT current can be isolated from all other contaminating signals. We used synaptic stimulation and photolysis of caged glutamate to characterize the current in PCs that is resistant to high concentrations of glutamate receptor antagonists. Some of this response is inhibited by the high-affinity EAAT antagonist TBOA (DL-threo-beta-benzyloxyaspartic acid), whereas the remaining current shows properties inconsistent with glutamate transport. By subtracting this residual non-EAAT current from the response recorded in glutamate receptor antagonists, we have obtained an estimate of postsynaptic uptake near physiological temperature. Analysis of such synaptic EAAT currents suggests that, on average, postsynaptic EAATs take up 11,300,000 glutamate molecules in response to a single climbing fiber action potential.
机译：位于神经元和神经胶质细胞上的兴奋性氨基酸转运蛋白（EAAT）负责限制细胞外谷氨酸的浓度，但尚未确定神经元和神经胶质EAAT的具体作用。在攀爬纤维到小脑的Purkinje细胞（PC）突触时，释放的一部分谷氨酸迅速被位于突触后PC上的神经元EAAT结合并使其失活。因为运输涉及离子的化学计量运动并且是电致的，所以由EAAT介导的突触后电流应允许精确计算突触后谷氨酸摄取的量。但是，只有将化学计量的EAAT电流与所有其他污染信号隔离开来，这才有可能。我们使用了笼状谷氨酸的突触刺激和光解作用来表征PC中对高浓度谷氨酸受体拮抗剂具有抗性的电流。高亲和力的EAAT拮抗剂TBOA（DL-苏-β-苄氧基天冬氨酸）抑制了某些这种反应，而其余电流则显示出与谷氨酸转运不一致的特性。通过从谷氨酸受体拮抗剂中记录的反应中减去这种残留的非EAAT电流，我们获得了在生理温度附近对突触后摄取的估计。对此类突触EAAT电流的分析表明，响应于单个攀爬纤维动作电位，平均而言，突触后EAAT吸收11,300,000个谷氨酸分子。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号