After Google Open-Sourced a Fruit Fly's Brain, It Learned to Play Games and Trade Crypto...

Author: Nancy, PANews

A fruit fly, just after its entire brain was "mapped," has already taken the tech and crypto communities by storm.

Recently, after Google open-sourced the complete fruit fly brain connectome, this decade-long neuroscience research quickly moved beyond the lab. People have made it play games, watch videos, make economic decisions, and even directly issue and trade cryptocurrencies.

After the Fruit Fly Brain Was Replicated by AI, Netizens Found New Ways to Play

On September 3, Google's research team, in collaboration with HHMI Janelia Research Campus and scientific partners, announced the first complete connectome of an adult male fruit fly brain and central nervous system, MaleCNS v1.0. The results were published the same day in the journal Cell. This means that for the first time, scientists have fully reconstructed the neural wiring of a real adult male fruit fly—from the brain, optic lobes, to the ventral nerve cord—down to the level of individual neurons and synapses.

AI played a major role. The team reconstructed millions of two-dimensional electron microscope slices into three-dimensional neural morphologies, and after manual proofreading and annotation, ultimately identified more than 166,000 neurons, approximately 125 million synaptic connections, and about 11,700 neuron types. By neuron count, this is one of the largest manually proofread complete brain maps to date.

More importantly, this map not only tells researchers "what's inside a fruit fly's brain," but also extends the neural wiring all the way to the optic lobes and the complete neck connective, allowing people to trace from sensory input to motor output along the same fruit fly's neural pathways.

Of course, the fruit fly central nervous system has only about a hundred thousand neurons, which is nowhere near the scale of the human brain with its roughly 86 billion neurons. But for neuroscience, this complete map of the male central nervous system is still an extremely valuable "instruction manual."

And once this map was made public, things quickly became interesting. This fruit fly, which originally existed only in the lab, soon became a "new toy" for developers and netizens, with all sorts of wild experiments popping up.

For example, developer @evnsnclr used GPT-6 Astra to connect the fruit fly's neural network simulation to the 3D sandbox game Minecraft, using simulated neural activity to drive a virtual fruit fly to perform actions like flying, grooming, eating, and escaping.

A Coinbase software engineer used the complete MaleCNS v1.0 connectome of an adult male fruit fly to try to train the fruit fly brain to play the classic game Doom. In the experiment, each frame of the game screen stimulates sensory neurons, and neural activity is mapped to game control commands; when the fruit fly takes damage, stimulation is applied to two PPL101 dopamine cells as a reinforcement signal, to observe whether the fruit fly brain can learn to survive in the game.

Some players also shared videos of a fruit fly brain simulation swinging a lightsaber to hit blocks in the VR game Beat Saber, saying they are currently training its visual cortex responsiveness, with the goal of achieving fully autonomous reactive gameplay through reinforcement learning, hoping to use the fruit fly's complete connectome to explore the learning capabilities of small-scale biological brains in complex rhythm tasks.

Tesla software engineer Kevin fed the "Bad Apple" song video into a fruit fly brain simulator, displaying real-time neural activity patterns while simultaneously driving the fruit fly model's leg and wing movements. Others have created browser-based WebGPU interactive simulations based on the fruit fly brain connectome, where users can "draw" neurons in Chrome and stimulate them, observing in real time the 3D fruit fly model's walking, turning, flying, or escaping behaviors.

Some netizens, not satisfied with just making the fruit fly play games, started assigning even more absurd tasks. Someone gave the fruit fly a "brain-control enhancement," forcing it to scroll through short videos on "FlyTok," and artificially enhanced it by measuring dopamine neuron activity, trying to give it maximum pleasure and create a fruit fly happier than all other fruit flies combined. Another person connected the fruit fly's brain to the Central Bank of the Republic of Turkey (TCMB) to let it decide interest rates. The results showed that compared to humans, the fruit fly generally set lower interest rates, while the final inflation rate was not much different.

Moreover, as netizens kept throwing the fruit fly into various "nightmare environments," some developers began to speak up for it, saying they are developing a simulator so that this fruit fly doesn't have to endure such torment and can just fly freely in a virtual fruit fly paradise.

These wildly imaginative derivative experiments quickly took a neuroscience research result out of the lab and turned it into a hot topic of entertainment and discussion, with some related posts even attracting tens of millions of views.

The Fruit Fly Starts Trading Crypto Autonomously, Related Meme Coin Market Cap Soars to Tens of Millions

Such a buzzworthy open experiment naturally caught the attention of the crypto community.

Someone directly had the fruit fly brain autonomously issue tokens on-chain. Users can view the fruit fly's neural activity and blockchain verification records through a related website, replay the entire token issuance process, and even interact directly with this simulated fruit fly.

Some developers tried to have the digital fruit fly trade meme coins. In this experiment, real-time price data is converted into the fruit fly's taste and smell inputs, and the simulated fruit fly's behavior determines trading actions: walking forward means buy, backing up means sell, and grooming means hold.

Others had the fruit fly look at candlestick charts to trade crypto. Coinbase software engineer Alex Wormuth connected the fruit fly's full brain connectome to a trading system, letting it start with $100 and autonomously decide Bitcoin buys and sells on Coinbase. Specifically, Bitcoin prices are encoded as visual inputs, and simulated neural activity is directly converted into trading commands; when a trade is profitable, the system stimulates dopamine neurons, providing the fruit fly with reward-like feedback for reinforcement learning. So far, this fruit fly's trading record is not bad, with a cumulative loss of only 0.59%.

But the hottest thing in the crypto market is the meme coin FLYBRAIN, issued on Robinhood Chain by developers using a real fruit fly full brain connectome simulation system. In this project, the fruit fly brain is responsible for generating the token description and ticker, while the experimental setup determines the name, trading pair, and tax rate. The developers said the entire system did not train new neural connections, but only adjusted synaptic weights, and verified through light/dark mode tests that the fruit fly's visual input indeed participated in decision-making.

Possibly influenced by a16z co-founder Marc Andreessen following its account, the meme coin's market cap once exceeded $55 million, and has now fallen back to about $27 million. Interestingly, FLYBRAIN's liquidity pool trading pair deliberately chose Google.

From a real fruit fly, to a digital fruit fly, to an on-chain fruit fly, the originally static neural connectome is turning into a digital brain that anyone can call upon, simulate, and explore, and has also launched a new on-chain experiment.