Google's fully mapped fruit fly brain is barely a week old, and it's already been put to work doing what any sufficiently advanced piece of neuroscience apparently must: playing Doom.
Last week, Google Research, working alongside HHMI Janelia Research Campus and the wider scientific community, announced it had fully mapped the complete brain and central nervous system of an adult male fruit fly for the first time. The team used AI to stitch together millions of 2D images into a 3D model, reconstructing more than 166,000 neurons in what Google called "a major milestone in neuroscience." The resulting connectome (a detailed map of the brain's neural connections), MaleCNS v1.0, was released publicly for download.
It took only a few days for engineers to start putting it through its paces. Coinbase engineer Alex Wormuth was among the first, announcing that he was training the fly brain to play the original Doom. "Each Doom frame stimulates sensory neurons," Wormuth explained. "Neural activity is mapped to game controls. Damage triggers a stimulus to two PPL101 dopamine cells as reinforcement." Wormuth also published a live feed of the fly's progress, showing both its in-game point of view and a third-person render of its little digital body wandering through Doom's corridors. As of the latest count, the fly was on its 6,385th attempt and still wasn't doing particularly well.
Doom wasn't the only game to get the fly-brain treatment. Engineer domi, posting on Bluesky, trained the connectome to play the rhythm-action game Beat Saber, using the fly's brain to decide when to turn and its "courtship song" behaviour to determine when to swing. Domi's project, called Aimbug, later extended the same approach to shooters. "The more aroused the fly is, the harder it tries to shoot," domi noted.
Others have joined in since, with software engineer Jessica Paquette getting the fly brain running through Super Mario 64 and admitting the project was "literally 100% vibe coded" for fun. YouTuber Ro0oney took a different route entirely, using Flywire.AI, a separate but similar connectome project developed with Princeton University, to get a fly brain playing Minecraft. Flywire's model is based on a female fruit fly's brain rather than Google's male one and reconstructs a slightly different number of neurons, but the underlying approach is the same. Other projects floating around social media include a fly-controlled driving simulation and an escape room built specifically to navigate the connectome.
Frequently Asked Questions
Open a question for an answer from TweakTown's coverage of this news, or ask your own below.
What is MaleCNS v1.0, and how can researchers download it?
What kinds of neuroscience research could Google’s mapped adult male fruit fly brain help with next?
How is the fly brain’s activity being translated into Doom controls in Alex Wormuth’s setup?
How does Flywire.AI differ from Google’s MaleCNS v1.0, beyond being based on a female fruit fly?
Have a question that isn't listed here? Ask below, and TweakBot will answer it.
Google has framed the fly brain map as a foundational neuroscience resource, one that could take years to explore fully. For now, though, its most visible legacy is a growing pile of side projects proving that if a brain can be mapped, someone, somewhere, will try to make it play a video game.
