Synapse-resolution wiring diagrams of fly brains and nerve cords, and where to download them.
htem/BANC-project README (CC BY 4.0)Harvard Medical School (Lee & Wilson labs), Princeton University (Murthy lab), Harvard (Drugowitsch lab)
Connectome of a single adult female fruit fly imaged at 4 nm by serial-section EM, covering her brain and ventral nerve cord together at synapse resolution, which no earlier dataset had managed in one animal. The README reports about 188,000 neurons and 199 million predicted synapses; the analysis code (mostly R) and the Dataverse data are both released under CC BY 4.0. The paper by Bates, Phelps, Kim, Yang and colleagues was published open access in Nature in 2026.
Princeton University (Murthy & Seung labs) with the FlyWire consortium
Whole-brain connectome of an adult female fruit fly, built by AI segmentation of the FAFB electron-microscopy volume followed by community proofreading led from Princeton. Version 783, served through the Codex explorer, holds 139,255 proofread neurons and tens of millions of synapses with neurotransmitter predictions. The flagship paper (Dorkenwald et al.) appeared in Nature in 2024 alongside companion annotation papers.
University of Cambridge (Michael Winding et al.)
Complete synaptic wiring diagram of an entire insect brain, reconstructed from a first-instar Drosophila larva and published in Science in March 2023 by a team led by Michael Winding (University of Cambridge). It comprises 3,016 neurons and about 548,000 synapses, and the analysis highlighted heavy multisensory integration, interhemispheric crosstalk and recurrent circuit motifs.
HHMI Janelia FlyEM / University of Cambridge / MRC LMB / Google Research
The first complete wiring diagram of an adult male fruit fly's whole central nervous system: brain, optic lobes and ventral nerve cord in one volume, with more than 166,000 neurons. Released as open data under CC-BY, it is the dataset behind the September 2026 wave of fly-brain demos.
Harvard Medical School (Wei-Chung Allen Lee lab)
GridTape-TEM volume of an adult female fruit fly's ventral nerve cord from the Lee lab at Harvard Medical School, with automated reconstruction and an ongoing community proofreading effort. The original EM dataset was described in Cell in 2021, and the connectomic reconstruction (Azevedo, Lesser, Phelps, Mark et al.) in Nature in 2024. This repository hosts the pip-installable fanc-fly Python package (GPL-3.0) and the project wiki, which fanc.community redirects to.
HHMI Janelia Research Campus (FlyEM Project Team)
Dense synaptic-level reconstruction of a large part of the central fly brain, including the mushroom body and central complex, produced by Janelia's FlyEM team. It contains roughly 25,000 neurons sorted into thousands of cell types, with v1.0 released in January 2020 and v1.2 in December 2020. The overview paper was published in eLife and the data is served through neuPrint.
HHMI Janelia FlyEM, Cambridge Connectomics Group, Google Research
Complete connectome of the ventral nerve cord of an adult male fruit fly, the structure that plays the role of a spinal cord and drives most motor behavior. Released in June 2023 (v1.0) and updated to v1.2 in March 2024 by Janelia's FlyEM team with Cambridge and Google Research, it covers about 23,000 neurons with around 10 million presynaptic sites. Three accompanying papers were published in eLife.
HHMI Janelia FlyEM Project Team with Google Connectomics
Complete wiring diagram of the right optic lobe of an adult male fruit fly, the visual-processing region, produced by Janelia's FlyEM team with Google's connectomics group. It catalogs more than 50,000 neurons in over 700 types, including roughly 16,000 intrinsic and 32,000 connecting neurons, and is served on neuPrint as optic-lobe v1.1 after a 2024 data release. The accompanying paper, a connectome-driven inventory of a complete visual system, was published in Nature in 2025.
Fly Brain Hub
