A Connectome of the AdultDrosophilaCentral Brain
Authors: Xu C. Shan , Januszewski Michal , Lu Zhiyuan , Takemura Shin-ya , Hayworth Kenneth J. , Huang Gary , Shinomiya Kazunori , Maitin-Shepard Jeremy , Ackerman David , Berg Stuart , Blakely Tim , Bogovic John , Clements Jody , Dolafi Tom , Hubbard Philip , Kainmueller Dagmar , Katz William , Kawase Takashi , Khairy Khaled A. , Leavitt Laramie , Li Peter H. , Lindsey Larry , Neubarth Nicole , Olbris Donald J. , Otsuna Hideo , Troutman Eric T. , Umayam Lowell , Zhao Ting , Ito Masayoshi , Goldammer Jens , Wolff Tanya , Svirskas Robert , Schlegel Philipp , Neace Erika R. , Knecht Christopher J. , Alvarado Chelsea X. , Bailey Dennis A. , Ballinger Samantha , Borycz Jolanta A , Canino Brandon S. , Cheatham Natasha , Cook Michael , Dreher Marisa , Duclos Octave , Eubanks Bryon , Fairbanks Kelli , Finley Samantha , Forknall Nora , Francis Audrey , Hopkins Gary Patrick , Joyce Emily M. , Kim SungJin , Kirk Nicole A. , Kovalyak Julie , Lauchie Shirley A. , Lohff Alanna , Maldonado Charli , Manley Emily A. , McLin Sari , Mooney Caroline , Ndama Miatta , Ogundeyi Omotara , Okeoma Nneoma , Ordish Christopher , Padilla Nicholas , Patrick Christopher , Paterson Tyler , Phillips Elliott E. , Phillips Emily M. , Rampally Neha , Ribeiro Caitlin , Robertson Madelaine K , Rymer Jon Thomson , Ryan Sean M. , Sammons Megan , Scott Anne K. , Scott Ashley L. , Shinomiya Aya , Smith Claire , Smith Kelsey , Smith Natalie L. , Sobeski Margaret A. , Suleiman Alia , Swift Jackie , Takemura Satoko , Talebi Iris , Tarnogorska Dorota , Tenshaw Emily , Tokhi Temour , Walsh John J. , Yang Tansy , Horne Jane Anne , Li Feng , Parekh Ruchi , Rivlin Patricia K. , Jayaraman Vivek , Ito Kei , Saalfeld Stephan , George Reed , Meinertzhagen Ian , Rubin Gerald M. , Hess Harald F. , Scheffer Louis K. , Jain Viren , Plaza Stephen M. 
Published: January 2020

The neural circuits responsible for behavior remain largely unknown. Previous efforts have reconstructed the complete circuits of small animals, with hundreds of neurons, and selected circuits for larger animals. Here we (the FlyEM project at Janelia and collaborators at Google) summarize new methods and present the complete circuitry of a large fraction of the brain of a much more complex animal, the fruit flyDrosophila melanogaster. Improved methods include new procedures to prepare, image, align, segment, find synapses, and proofread such large data sets; new methods that define cell types based on connectivity in addition to morphology; and new methods to simplify access to a large and evolving data set. From the resulting data we derive a better definition of computational compartments and their connections; an exhaustive atlas of cell examples and types, many of them novel; detailed circuits for most of the central brain; and exploration of the statistics and structure of different brain compartments, and the brain as a whole. We make the data public, with a web site and resources specifically designed to make it easy to explore, for all levels of expertise from the expert to the merely curious. The public availability of these data, and the simplified means to access it, dramatically reduces the effort needed to answer typical circuit questions, such as the identity of upstream and downstream neural partners, the circuitry of brain regions, and to link the neurons defined by our analysis with genetic reagents that can be used to study their functions.

Note: In the next few weeks, we will release a series of papers with more involved discussions. One paper will detail the hemibrain reconstruction with more extensive analysis and interpretation made possible by this dense connectome. Another paper will explore the central complex, a brain region involved in navigation, motor control, and sleep. A final paper will present insights from the mushroom body, a center of multimodal associative learning in the fly brain.