The larval 4D standard brain of Drosophila melanogaster on a single cell level

大脑中的行为输出是如何根据外部感官输入、内部动机状态甚至是通过先前经验获得的知识组织起来的？理解这些过程是神经科学领域最重要的问题。几个世纪以来，脑功能科学的研究人员一直在将行为的特性映射到大脑的各个区域。然而，从简单的地图到普遍接受的模型这一步已经证明是极其困难的。在极其简化的模式生物（例如秀丽隐杆线虫或Aesthesia）中，只有在有限的水平上才能与人类进行有意义的比较，而更复杂的脊椎动物系统（例如小鼠，斑马鱼）具有数值，伦理和技术限制，经典的遗传模式生物果蝇获得了重要的中间位置。最近的方法要么尝试建立完整的连接组的幼虫大脑的连续透射电子显微镜（TEM）或工作的3D脑图谱的基础上，其成年同行的共聚焦显微镜堆栈不同的GAL 4驱动线。然而，这两种方法都达到了生物学极限;而TEM方法仅限于单个大脑的解剖水平，但允许基于其高分辨率建立连接体，3D配准允许将解剖数据与功能研究联系起来。然而，到目前为止，它被限制在约10%的成年果蝇大脑，由于其约200.000个神经元的数值复杂性。因此，我们提出了一个联合的方法来建立一个全面的4D重建的约10.000个神经元的幼虫大脑的基础上GAL 4，莱克萨和分裂GAL 4线。该项目将通过在神经科学和信息学领域工作的三个小组的独特专业知识来实现; 1）图姆实验室将通过免疫组织化学技术和共聚焦显微镜来可视化这些神经元。2)Merhof实验室将根据其解剖信息将这些神经元注册到标准大脑中。3)布勒实验室将在开放访问数据库中处理、组织和可视化处理后的数据。此外，B. Dickson和J. Truman都位于HHMI Janelia Farm Research Campus（美国），他们将通过提供世界上最大的遗传工具集和幼虫大脑解剖学原始数据来支持这一奋进。总之，我们的方法将在神经元水平上以4D重建幼虫大脑;同时，它还将定义一组新的注释（在开放访问数据库中）和免费访问的神经遗传学工具，以研究整个大脑中单个神经元的特定功能。通过这一点--这是第一次--将有可能建立一个共同的资源库，为欧洲迅速增长的果蝇幼虫神经生物学社区提供支持。

How is behavior output organized in a brain based on external sensory inputs, internal motivational states or even knowledge gained through prior experience? Understanding these processes is the most essential issue in the field of neuroscience. For centuries, researchers in the functional brain sciences have been mapping properties of behavior to areas of the brain. Yet, the step from simple maps to a generally accepted model has proven exceedingly difficult. Among the extremely reduced model organisms (e.g. C.elegans or Aplysia) that only on a constricted level allow for meaningful comparisons with humans, and more complex vertebrate systems (e.g. mouse, zebra fish) that have numerical, ethical and technical constraints, the classical genetic model organism Drosophila has acquired an important intermediate position. Recent approaches either try to establish the complete connectome of the larval brain by serial transmission electron microscopy (TEM) or work on a 3D brain atlas for its adult counterpart based on confocal microscopy stacks of different GAL4 driver lines. However, both approaches have reached biological limits; whereas the TEM method is restricted to the anatomical level of a single brain but allows for the establishment of the connectome based on its high resolution, the 3D registration allows linking anatomical data to functional studies. However, so far it is restricted to about 10% of the adult Drosophila brain due to its numerical complexity of about 200.000 neurons.Therefore, we propose a joined approach to establish a comprehensive 4D reconstruction of the about 10.000 neurons of the larval brain based on GAL4, LexA and split-GAL4 lines. The project will be realized by the unique expertise of three groups working in the field of neuroscience and informatics; 1) The Thum lab will visualize these neurons by immunohistochemical techniques and confocal microscopy. 2) The Merhof lab will register these neurons based on its anatomical information onto a standard brain. 3) The Bühler lab will process, organize and visualize the processed data in an open access database. In addition, the labs of B. Dickson and J. Truman, both located at the HHMI Janelia Farm Research Campus (USA) will support the endeavor by offering access to the world-wide largest set of genetic tools and anatomical raw data on larval brain anatomy. In summary, our approach will reconstruct the larval brain in 4D on the neuronal level; at the same time it will also define a new set of annotated (in an open access database) and freely accessible neurogenetic tools to investigate the particular function of single neurons within an entire brain. By that - for the first time - it will be possible to establish a common resource base that offers support for the rapidly growing neurobiology community in Europe working on the Drosophila larva.