Fig. 1: A connectomic reconstruction of a whole fly brain.

a, All neuron morphologies reconstructed with FlyWire. All neurons in the central brain and both optic lobes were segmented and proofread. Note that image and dataset are mirror inverted relative to the native fly brain. b, An overview of many of the FlyWire resources that are being made available. FlyWire leverages existing resources for electron microscopy imagery by Zheng et al.⁹, synapse predictions by Buhmann et al.⁷ and Heinrich et al.¹¹⁸, and neurotransmitter predictions by Eckstein et al.¹⁰. Annotations of the FlyWire brain dataset such as hemilineages, nerves and hierarchical classes are established in the accompanying paper¹². c, FlyWire uses CAVE⁵⁰ for proofreading, data management and analysis back end. The data can be accessed programmatically through CAVEclient, navis, fafbseg and natverse¹¹⁹, and through the browser in Codex, Catmaid Spaces and braincircuits.io. Static exports of the data are also available. d, The Drosophila brain can be divided into spatially defined regions based on neuropils⁸⁰ (Extended Data Fig. 1). Neuropils for the lamina are not shown. D, dorsal; L, lateral; P, posterior. e, Synaptic boutons in the fly brain are often polyadic such that there are multiple postsynaptic partners per presynaptic bouton. Each link between a pre- and a postsynaptic location is a synapse. f, Neuron tracts, trachea, neuropil and cell bodies can be readily identified from the electron microscopy data acquired by Zheng et al.⁹. Scale bar, 10 μm.