扫描透射电子断层扫描术研究海马神经元突触的超微结构  

STEM Tomography for Thick Synaptic Specimen

作　　者：李霞[1,2] 戎叶[1] 李叶菲[1] 薛艳红[3] 张云峰[2] 季刚[3] 

机构地区：[1]浙江大学医学院,杭州310058 [2]南通大学航海医学研究所,江苏南通226001 [3]中国科学院生物物理研究所,北京100101

出　　处：《生物物理学报》2012年第11期886-895,共10页Acta Biophysica Sinica

基　　金："973"计划项目(J20110170);国家自然科学基金项目(J20121326)~~

摘　　要：由于突触在神经信号传递及可塑性研究中的重要地位,其亚显微结构的观察一直被认为是神经科学领域备受关注的研究问题。但是,至今仍然缺乏有效的研究手段来实现高分辨率的突触超微结构解析。近年来,随着电子显微镜技术突飞猛进的发展,使得对该问题的深入探讨成为可能。本文中,采用扫描透射电子断层扫描术对比较厚的脑片样本(<1μm)中突触的超微结构进行了观察,从三维水平上对突触复杂的内部精细结构进行探测,分析了突触囊泡的大小、形态、囊泡在突触前的分布及内体样囊泡的循环过程,为神经元突触功能研究提供了一种全新的方法和更为有效的手段。Synapses play a important role in neural signaling transmission and sculpting the circuitry of the nervous system. Since then, morphological analysis of the synaptic structure using microscopy, especially submicroscopic structure using electron microscopy, has been considered to be vital in the field of neuroscience research. However, investigation of high-resolution synaptic ultra structure has been hampered by the lack of effective means till now. Here, scanning transmission electron microscopy （STEM） tomography was applied to thick biological specimens （〈1 i^m） using Titan Krios 300 kV field emission electron microscopy in hippocampal slices. By employing STEM tomography and the following software processing, 400 or 800 nm-thick specimen was successfully reconstruction modeled. Analysis of synaptic vesicle size, shape, presynaptic distribution and budding pathway of endosome-like vesicles were also made to probe the synaptic complex internal fine structure in three dimensions. This study opens up a new window for the study of synaptic function and may provide powerful support to elucidate synaptic recycling mechanism.

关 键 词：突触 突触囊泡 内体样囊泡 三维重构 扫描透射电子断层扫描术 

分 类 号：R338.13[医药卫生—人体生理学]