Researchers from Google and the Janelia Research Campus of the Howard Hughes Medical Institute announced a major milestone in neuroscience last week. On September 3, scientists published the results of a decade-long project to map every neural connection in the brain and central nervous system of an adult male fruit fly. And of course, a few days later, the Internet began allowing video games to be played. “With more than 166,000 neurons and 125 million synaptic connections, this is the largest brain map by number of neurons to date, providing a critical resource for scientists to use fruit flies as a model organism to study how the brain works,” Google said in a blog post. The map, known as a connectome, is essentially a wiring diagram that shows how the fly’s neurons are connected. Researchers created it by cutting the nervous system into millions of extremely thin sections, imaging them with an electron microscope, and then using computers and artificial intelligence to convert those 2D images into 3D reconstructions of neurons. Scientists then spent years verifying and recording the results. Google says that because it is not yet possible to map the approximately 86 billion neurons in a human brain, scientists are starting with smaller organisms like fruit flies. The project aims to help scientists learn how animals’ nervous systems “perceive the world, react to stimuli, and how damaged neural pathways might one day be repaired.” But for now, people online are using that same data for their own experiments. For example, software engineer Alex Wormuth posted on September 6 that he is using data from the project to train a simulated fly brain to play Doom. “Each frame of Doom stimulates sensory neurons. The neural activity is mapped to the game controls. The damage triggers a stimulus to two PPL101 dopamine cells as reinforcement,” he wrote in a post on Each frame of Doom stimulates sensory neurons. Neural activity is mapped to game controls. The damage triggers a stimulus to two PPL101 dopamine cells as reinforcement. Will the fly learn to… https://t.co/ObCJ03gxy3 pic.twitter.com/H2YDBtyuR8 — Alex Wormuth (@nftechie_) September 6, 2026 The project will be broadcast live online. Another developer, Jessica Paquette, posted on Monday about a similar project that uses data from the fly’s brain to play Super Mario 64. In a video she posted, Mario can be seen jumping and repeatedly crashing into walls. playing mario 64 using a fly’s brain pic.twitter.com/G4BmfMSWb8 — Jessica Paquette (@barrelshifter) September 7, 2026 Paquette also posted the project’s code on GitHub, where she wrote that the code is “100% coded with GPT Astra.” “I have successfully run the entire retained fruit fly connectome MaleCNS v1.0, all 166,700 neurons, within Minecraft, with its simulated neural activity driving the movement of a fly,” another user wrote on X. And it wasn’t just video games that people experimented with. One X user said he tuned a simulated fly’s brain to do YMCA poses in response to four different tones. And another user made the simulated fly brain “look” at the viral Bad Apple!! Animation to see how he reacted. It wouldn’t be surprising to see even more fly brain projects appear online in the coming months, at least until programmers get a new brain to play with. Conveniently, Google is already looking beyond the flies. The company is working with researchers on connectomes for fish and mice.
