ORGANIZATION OF ACTIVE ZONE WITHIN PRESYNAPTIC TERMINALS ON HIPPOCAMPAL NEURONS

尽管突触结构和功能之间的相关性 已经详细研究过的神经肌肉交界处，我们面临着许多 公开的问题。对中枢突触的了解就更少了。 最近的研究表明，单个突触接触的大小 与其功能相关。尤其是小泡的数量 停靠在活动区似乎准确地预测了释放 那次接触的概率。然而，目前还不清楚是否每一次 囊泡对释放概率的贡献是相同的。一模一样的 定位停靠小泡的位置可能揭示功能性 不同小泡之间的差异。因此，我们重建了 用高压电子显微镜和电子显微镜观察海马区突触 层析三维重建。使用此方法，我们可以解析 总误差小于10 nm的每个小泡的位置 尺寸，而从连续截面重建是有限的 在z轴上的分辨率降低6倍。到目前为止，有10个突触 都被重建了。对接后的中心到中心的距离 使用NCMIR开发的程序xdsphere计算囊泡 由Stephan Lamont提出，并用对关联函数进行分析。 该函数显示了一个复杂但有序的模式，这是一致的 在活动区之间。这项工作在冬季大脑会议上发表 今年在犹他州帕克城举行的会议。

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.