德国马克斯普朗克生物智能研究所Herwig Baier研究团队近日取得一项新成果。他们的最新研究在突触水平完成了斑马鱼幼体大脑神经回路的重建。该项研究成果发表在2022年10月24日出版的《自然-方法学》上。

为了重建大脑突触连接，研究人员通过连续的块面电子显微镜在体素尺寸14×14×25 nm³下，对幼虫斑马鱼的大脑进行了切片和成像。研究人员使用负载填充网络算法对结果数据集进行分割，自动检测化学突触，并通过与透射电子显微图像和光微观重建比较来验证结果。神经元及其连接以可查询和可扩展的数字地址簿形式存储。研究人员重建了一个由208个神经元参与的视觉运动处理网络，其中大多数位于前体，并通过双光子钙成像在同一标本中对前体进行了功能表征。

此外，研究人员还绘制了脑顶盖中两个表面中间神经元的407个突触前和突触后伴侣。该研究揭示的资源是斑马鱼神经系统突触回路分析的基础。

研究人员表示，突触连接的密集重建需要整个大脑的高分辨率电子显微镜图像和工具，以有效地追踪整个大脑中的神经元线。

附：英文原文

Title: Automated synapse-level reconstruction of neural circuits in the larval zebrafish brain

Author: Svara, Fabian, Frster, Dominique, Kubo, Fumi, Januszewski, Micha, dal Maschio, Marco, Schubert, Philipp J., Kornfeld, Jrgen, Wanner, Adrian A., Laurell, Eva, Denk, Winfried, Baier, Herwig

Issue&Volume: 2022-10-24

Abstract: Dense reconstruction of synaptic connectivity requires high-resolution electron microscopy images of entire brains and tools to efficiently trace neuronal wires across the volume. To generate such a resource, we sectioned and imaged a larval zebrafish brain by serial block-face electron microscopy at a voxel size of 14×14×25nm3. We segmented the resulting dataset with the flood-filling network algorithm, automated the detection of chemical synapses and validated the results by comparisons to transmission electron microscopic images and light-microscopic reconstructions. Neurons and their connections are stored in the form of a queryable and expandable digital address book. We reconstructed a network of 208 neurons involved in visual motion processing, most of them located in the pretectum, which had been functionally characterized in the same specimen by two-photon calcium imaging. Moreover, we mapped all 407 presynaptic and postsynaptic partners of two superficial interneurons in the tectum. The resource developed here serves as a foundation for synaptic-resolution circuit analyses in the zebrafish nervous system.

DOI: 10.1038/s41592-022-01621-0

Source: https://www.nature.com/articles/s41592-022-01621-0