在快速的中央突触中,发射器释放率的细胞内依赖性
1Abteilung Membranbiophysik, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany. rschneg@gwdg.de
Nature
|September 6, 2000
概括
快速释放的神经递质依赖于. 这项研究表明,低细胞内水平 (10微米) 引发了中枢神经系统突触中的快速囊泡融合和释放.
科学领域:
- 神经科学是一个神经科学.
- 细胞生物学 细胞生物学
- 生物物理学的生物物理.
背景情况:
- 突触囊泡融合和神经递质释放对于神经元信号传递至关重要.
- 快速释放的神经递质被认为需要高局部细胞内度 ([Ca2+]i>100微米).
- 在突触释放部位缺乏局部[Ca2+]i的实验估计.
研究的目的:
- 通过实验确定快速释放神经递质所需的局部细胞内度 ([Ca2+]i).
- 为了研究结合和囊泡融合的动力学.
- 了解快速突触传输对的敏感性.
主要方法:
- 离子在大型突触终端 (赫尔德的玻璃杯) 中脱.
- 在受控[Ca2+]i步骤后,神经递质释放速率的动态分析.
- 测量囊泡池耗尽的情况.
主要成果:
- [Ca2+]i的阶段式升高到10微米诱导了快速发射器释放.
- 大约80%的可用囊泡在不到3个月的时间内被耗尽.
- 过渡的[Ca2+]i升高到25微米可以解释单次作用电位期间的释放.
- 传感器在正常释放概率下没有和.
结论:
- 快速神经递质释放可以由较低的[Ca2+]i触发,而不是以前假设的.
- 高合作性和传感器的不和度提高了突触传输的灵敏度.
- 暂时的局部信号足以快速的突触传输.
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