Harlow M, Ress D, Koster A, Marshall R M, Schwarz M, McMahan U J
Department of Neurobiology, Stanford University School of Medicine, CA 94305, USA.
J Physiol Paris. 1998 Apr;92(2):75-8. doi: 10.1016/S0928-4257(98)80141-1.
We used EM tomography to examine the fine structure of the apparently amorphous electron dense material that is seen at active zones of axon terminals when viewed by conventional 2D electron microscopy. Serial 1-nm optical slices from 3D reconstructions of individual thin tissue sections reveal that the material is composed of an interconnecting network of elongate components directly linked to synaptic vesicles and the presynaptic membrane. Each vesicle at the active zone that lies adjacent to the presynaptic plasma membrane has several such connections. Information provided by reconstruction data may be useful in generating experiments aimed at understanding the mechanisms involved in the docking of synaptic vesicles and their exocytosis during synaptic transmission.
我们使用电子显微镜断层扫描技术来检查这种看似无定形的电子致密物质的精细结构，在传统二维电子显微镜观察下，这种物质可见于轴突终末的活性区。对单个薄组织切片进行三维重建得到的一系列1纳米光学切片显示，该物质由直接连接到突触小泡和突触前膜的细长成分相互连接的网络组成。位于突触前质膜附近活性区的每个小泡都有几个这样的连接。重建数据提供的信息可能有助于开展实验，以了解突触传递过程中突触小泡对接及其胞吐作用所涉及的机制。
