FlyBrain

Interactive browser simulation of the Drosophila melanogaster (fruit fly) brain. 139,255 neurons and 2.7M connections from the FlyWire FAFB v783 connectome run in real time via a leaky integrate-and-fire model in a Web Worker.

The fly is not scripted. Behavior emerges from signal propagation through weighted neural connections: place food and watch it seek, touch it and watch it startle, change the light and watch it navigate.

Usage

Open index.html in a browser (or visit the hosted version). The fly loads the full connectome and begins exploring. Use the toolbar to interact:

• Feed -- click to place food. The fly seeks and eats it when hungry.
• Touch -- click on the fly. Head, thorax, abdomen, and legs trigger different responses.
• Air -- click and drag near the fly to blow wind.
• Light -- cycle through Bright, Dim, Dark. The fly exhibits phototaxis.
• Temp -- cycle through Neutral, Warm, Cool.

The bottom panel shows all 139K neurons firing in real time (WebGL), grouped by region: Sensory, Central, Drives, Motor.

Data Source

Connectome data from the FlyWire Whole-Brain Connectome:

Dorkenwald, S., Matsliah, A., Sterling, A.R. et al. Neuronal wiring diagram of an adult brain. Nature 634, 124--138 (2024). https://doi.org/10.1038/s41586-024-07558-y

The binary connectome file (data/neuron_meta.bin.gz) is derived from the FlyWire Codex public dataset (FAFB v783). Neurons are classified into functional groups (sensory, central, drives, motor) based on FlyWire cell type annotations.

Origin

Forked from heyseth/worm-sim, which simulated the 302-neuron C. elegans connectome in the browser. FlyBrain replaces the worm with a fruit fly and scales from 302 neurons to 139,255.

License

MIT License -- see license.md for details.

Acknowledgments

• FlyWire Consortium -- for mapping the complete adult Drosophila brain connectome and making the data publicly available.
• Timothy Busbice, Gabriel Garrett, Geoffrey Churchill and contributors to the GoPiGo Connectome -- original connectome-driven robot concept.
• Zach Rispoli -- porting the C. elegans connectome to JavaScript.
• Seth Miller -- creating worm-sim, the browser simulation this project is forked from.