ORGANIZATION OF ACTIVE ZONE WITHIN PRESYNAPTIC TERMINALS ON HIPPOCAMPAL NEURONS

虽然突触结构和功能之间的相关性 已经在神经肌肉接头处进行了详细研究，我们面临着许多 开放式问题。 中枢突触的了解甚至更少。 最近的研究表明，单个突触接触的大小 与其功能相关。 特别是囊泡的数量 停靠在活动区域似乎可以准确预测释放 该接触的概率。 然而，尚不清楚是否每个 囊泡对释放概率的贡献相同。 一个精确的 对接囊泡位置的绘图可能揭示功能 各个囊泡之间的差异。 因此，我们重构了 使用高压电子显微镜观察海马突触 断层扫描 3D 重建。 使用这个方法我们可以解决 每个囊泡的位置总共误差小于10 nm 尺寸，而连续切片的重建是有限的 z 轴分辨率降低 6 倍。 到目前为止，10个突触 已被重建。 对接的中心到中心距离 使用 NCMIR 开发的程序 xdsphere 计算囊泡 由 Stephan Lamont 编写，并使用配对相关函数进行分析。 该函数显示出复杂但有序的一致模式 活动区域之间。 这项工作在冬季大脑上发表 今年的会议在犹他州帕克城举行。

Although the correlation between synaptic structure and function has been studied in detail at the neuromuscular junction, we face many open questions. Central synapses are even less well understood. Recent studies have shown that the size of a single synaptic contact is correlated to its function. In particular the number of vesicles docked at the active zone seems to accurately predict the release probability of that contact. It is not clear, however, whether every vesicle contributes equally to the release probability. An exact mapping of the position of docked vesicles might reveal functional differences between individual vesicles. We, therefore, reconstructed hippocampal synapses by using high voltage electron microscopy and tomographic 3-D reconstructions. Using this method we can resolve the position of every vesicle with an error of less than 10 nm in all dimensions, whereas reconstructions from serial sections are limited to a 6 times lower resolution in the z-axis. Thus far, 10 synapses have been reconstructed. The center to center distances of the docked vesicles were calculated using the program xdsphere developed at NCMIR by Stephan Lamont and analyzed with the pair correlation function. The function shows a complex but orderly pattern that is consistent between active zones. This work was presented at the Winter Brain Conference this year in Park City, Utah.