Fly Brain Connectome: From Release to Real-World Machines

Episode 1 · AI Helps Map Complete Fruit Fly Connectome: 166,000+ Neurons, Largest Yet (2026-09-04, 12 posts)

On September 4, Google Research (including DeepMind), HHMI Janelia Research Campus, the MRC Laboratory of Molecular Biology and Cambridge University published the complete connectome of an adult male fruit fly's brain and central nervous system in Cell. The roughly 20-year project used AI to fuse millions of 2D images into 3D neuron morphologies, identifying over 166,000 neurons, nearly 11,700 cell types and about 125 million synapses—the largest cellular-level brain map to date.

Confirmed

• This extends previous head-only adult fly connectomes to the entire central nervous system (brain plus ventral nerve cord), with the reconstruction done by AI, setting a record of 166,000+ neurons.
• Per @ymatias, the Cell paper covers 166,000+ neurons and 125 million synapses; Science-affiliated coverage cites 166,700 neurons and 124 million synapses—a minor discrepancy between reports.
• The work was widely covered by @ThePlanckDiver, @ColbyHawker, @DrSingularity, @BraydonDymm and others; Science Corp founder Max Hodak reshared it (per @lukaszkaiser).
• @BraydonDymm notes practical value for research on vision, taste and social behavior; @ThePlanckDiver sees it as foundational data for understanding neural circuits and AI architecture research.

Why it matters

• @ColbyHawker views it as a concrete demonstration of AI for Science and a step toward mapping the human connectome.
• @BraydonDymm cautions that a human connectome remains out of reach for the foreseeable future—this is a milestone in basic neuroscience, not a prelude to mind uploading.

• Google uses AI to map full fruit fly brain, reconstructing 166,000+ neurons in 3D — burny_tech · 2026-09-04
• Google and HHMI unveil complete male fruit fly connectome with 166,000 neurons — BraydonDymm · 2026-09-04
• Fruit fly connectome complete, but human connectome still a long way off — BraydonDymm · 2026-09-04
• Google and HHMI release full male fruit fly connectome with 166,000 neurons — lukaszkaiser · 2026-09-04
• DeepMind uses AI to map all 166K+ neurons of a fruit fly brain — ColbyHawker · 2026-09-04
• AI maps full fruit fly brain and central nervous system for first time, 166,000+ neurons — Polymarket · 2026-09-04
• Google maps the complete male fruit fly brain in connectomics milestone — ThePlanckDiver · 2026-09-04
• After 20 Years, Complete Fruit Fly Connectome Maps 166,700 Neurons and 124.2M Synapses — burny_tech · 2026-09-04
• AI Helps Map the Entire Adult Fruit Fly Brain: 166,000+ Neurons Traced — Dr_Singularity · 2026-09-04
• Janelia completes full connectome of adult fruit fly's 166,000+ neurons after 20 years — burny_tech · 2026-09-04
• Google and HHMI map the complete male fruit fly brain: 166,000 neurons, 125M synapses — ymatias · 2026-09-05
• Fruit fly connectome completed after 20-year effort, mapping all 124 million neural contact points — CurieuxExplorer · 2026-09-05

Episode 2 · Full Fruit-Fly Connectome Runs in Minecraft, Driving an In-Game Fly (2026-09-05, 9 posts)

Georgia Tech graduate student Evan Smith (evnsnclr, also credited as Evan Sinclair Smith in reposts) announced that he successfully ran the complete MaleCNS v1.0 male fruit-fly whole-brain connectome in Minecraft—covering all 166,700 neurons and roughly 25.58 million directed edges (reported by 新智元 as 125 million synapses)—and used the simulated neural activity to directly drive the movement of an in-game fly, with real-time visualization of which neurons fire and what the fly decides to do. After the demo went viral, the author clarified he was not simulating the fly's consciousness or uploading a living brain into the game: the implementation is based on a reconstructed wiring diagram with simplified activity-propagation rules.

Confirmed

• evnsnclr (Evan Smith) announced running the MaleCNS v1.0 connectome with 166,700 neurons and 25.58 million directed edges in Minecraft, driving an in-game fly; the NeuroCraft Fly project page is live, V1 is still in development, and code plus a mod are planned
• Per Dan Jeffries and 新智元, the project was reportedly built with OpenAI's GPT-6 Astra; 新智元 says it took about two days, and that the connectome itself took HHMI Janelia, Cambridge and Google ten years and 44 person-years of manual proofreading
• Per paulcal, the original author clarified the demo is a reconstructed wiring diagram plus simplified propagation rules, not consciousness simulation or a living-brain upload; Polymarket confirmed the brain-science-meets-sandbox pairing drew massive attention

Unconfirmed

• Some researchers question whether it is merely a superficial simulation; the fidelity to real neural circuits has no independent verification (relayed by birchlse)
• Some reposts credit a different developer (menhguin); the original posts by evnsnclr are authoritative

Why it matters

• A rare attempt to port a complete model-organism whole-brain connectome into a general-purpose game environment, showing how connectome data can pair with real-time interactive simulation
• The author's clarification draws a line between 'running a connectome map' and 'simulating consciousness,' helping the public interpret such demos correctly
• If the simulation depth holds up, it could offer neuroscience a low-cost interactive experimental vehicle; if it is only surface-level, it suggests such cross-medium ports need stricter scientific evaluation

• Full Fruit Fly Connectome With 166,700 Neurons Runs Inside Minecraft, Driving a Fly's Movement — Dan_Jeffries1 · 2026-09-05
• Developer runs full fruit fly connectome — all 166,700 neurons — inside Minecraft — ZeroStateReflex · 2026-09-05
• Developer runs 166,700-neuron fruit fly brain simulation inside Minecraft using GPT-6 Astra — Polymarket · 2026-09-06
• Fruit fly connectome run in Minecraft, but experts question if it's real simulation — birchlse · 2026-09-06
• Full Fruit Fly Connectome With 166,700 Neurons Runs Inside Minecraft — lfschiavo · 2026-09-06
• Grad Student Ports the 166,700-Neuron Fly Connectome Into Minecraft in Two Days Using GPT-6 — 新智元 · 2026-09-06
• Viral fruit-fly connectome Minecraft demo: author clarifies it's not consciousness upload — paul_cal · 2026-09-06
• Full fruit fly connectome with 166,700 neurons runs inside Minecraft, driving simulated movement — burny_tech · 2026-09-07
• Full fruit-fly connectome with 166,700 neurons runs inside Minecraft — burny_tech · 2026-09-07

Episode 3 · Google Maps Entire Fruit Fly Brain with 166,000 Neurons (2026-09-06, 4 posts)

Google Research and HHMI Janelia released the first complete connectome of an adult male fruit fly brain and nervous system, mapping over 166,000 neurons by fusing millions of 2D images into 3D reconstructions with AI.

• Google and HHMI release largest cellular brain map: complete fly CNS with 166,000 neurons — udmrzn · 2026-09-06
• Google and HHMI Release Complete Fruit Fly Brain Connectome with 166,000 Neurons — matiroy · 2026-09-06
• Google AI reconstructs complete fruit fly brain map with 166,000+ neurons — round · 2026-09-06
• Google maps full fruit fly brain with AI, reconstructing 166,000+ neurons in 3D — zacharynado · 2026-09-06

Episode 4 · Full Fruit Fly Connectome with 166,700 Neurons Runs Inside Minecraft (2026-09-08, 3 posts)

A grad student used GPT-6 to wire the full 166,700-neuron MaleCNS fruit fly connectome—mapped over a decade by Google, Cambridge and others—into Minecraft in just two days, driving an in-game fly's motion with simulated neural activity.

• Full 166,700-neuron fruit fly connectome runs inside Minecraft — birchlse · 2026-09-08
• Grad student plugs fruit fly connectome into Minecraft in two days using GPT-6 — FuSheng_0306 · 2026-09-08
• Full fruit fly connectome with 166,700 neurons runs inside Minecraft to drive fly movement — ZeroStateReflex · 2026-09-10

Episode 5 · Fly Brain Connectome Simulation Plays Beat Saber in Real Time (2026-09-09, 5 posts)

A digital brain simulation built from the fruit fly whole-brain connectome, demonstrated by @lyraaaa, was connected to the rhythm game Beat Saber and managed to keep up with the beat in real time. The demo went viral around September 9 and is widely regarded as a landmark moment at the intersection of neuroscience and AI. What is confirmed: the fly connectome model can indeed play a real-time rhythm game; extrapolations to human brains remain speculation.

Confirmed

• The fruit fly whole-brain connectome model can play Beat Saber in real time in a simulated environment, demonstrated by @lyraaaa and corroborated by cixliv and others
• beffjezos commented that this amounts to "RL post-training on a biological brain" in a simulated environment, pushing connectome-level neural simulation into real-time interactive tasks
• Neuroscientist @jbohnslav said he never imagined such a scenario in all his years in the field

Unconfirmed

• Forward-looking claims by some sharers remain speculative: since a fly brain can in principle be fully mapped, perhaps a human brain could be too someday; whether a 1:1 digital reconstruction of a human brain would be conscious, and if not what would be missing, remains completely unanswered

Why it matters

• The demo showcases the fidelity of connectome-level simulation: an insect brain's emulation performing well in a real-time interactive game, which cixliv admitted he did not know how to process
• It moves the philosophical debate over whether digital brains could be conscious from abstraction toward something experimentally approachable, prompting Scobleizer to remark "I told you the future would be weird"

• A digital fruit fly brain can play Beat Saber — cixliv · 2026-09-09
• A simulated fly brain can play Beat Saber: RL post-training of biological brains in sim — ccerrato147 · 2026-09-09
• A fly brain can play Beat Saber, and the AI crowd is loving it — ID_R_McGregor · 2026-09-09
• Fruit fly connectome plays Beat Saber, reigniting digital consciousness debate — rickasaurus · 2026-09-09
• A fly brain connectome can play Beat Saber, stunning neuroscientists — giannis_daras · 2026-09-10

Episode 6 · Google and HHMI Release Complete Male Fruit Fly Brain Connectome (2026-09-09, 7 posts)

Google Research's Connectomics team, in collaboration with HHMI Janelia Research Campus, released the complete wiring diagram (connectome) of the adult male fruit fly brain and central nervous system—the largest brain map to date by number of proofread neurons. Google later recapped community research building on the dataset.

Confirmed

• The connectome covers over 166,000 neurons and roughly 125 million synaptic connections, extending from the brain into the spinal-cord-like nerve cord, with neurons classified into about 11,700 cell types.
• The team used AI to assemble millions of 2D images into 3D neural morphology for the full reconstruction.
• The work continues the 2020 female fruit fly hemibrain 3D reconstruction (25,000 neurons); with this release, both male and female maps are available.
• Google published a companion blog detailing the map and its impact on neuroscience; cross-species efforts such as zebrafish connectomics are ongoing.

Why it matters

• A complete connectome lets researchers trace neural circuits at single-synapse precision—a foundational dataset for understanding how brains process information and generate behavior, and key infrastructure for AI for Science.
• Compared with the 2020 hemibrain, the new map scales up neuron count and coverage substantially, building methods and engineering experience for larger vertebrate connectomes.

• Google and HHMI release complete wiring diagram of the male fruit fly nervous system — GoogleAI · 2026-09-09
• Google releases complete male fruit fly brain wiring diagram, its largest connectome yet — GoogleAI · 2026-09-09
• New fruit fly connectome maps 166,000 neurons and 125 million connections across both sexes — GoogleAI · 2026-09-09
• Google publishes blog detailing how fruit fly brain maps advance neuroscience — GoogleAI · 2026-09-09
• Google uses AI to map the complete fruit fly brain, reconstructing 166,000+ neurons in 3D — SunirKM · 2026-09-10
• Google and Janelia map full fly brain with AI: 166,000 neurons, 125 million connections — alex_verem · 2026-09-10
• Google Highlights Research Built on Full Connectome of Fruit Fly's 166,000 Neurons — GoogleAI · 2026-09-11

Episode 7 · Viral 'Fly Brain Plays Beat Saber' Turns Out to Be Overfit Replay (2026-09-10, 3 posts)

A demo of a fruit fly connectome 'playing' Beat Saber went viral, but was later clarified as overfit replay of prerecorded motions — visual recognition and reinforcement learning remain unfinished, and the connectome is just a static wiring map.

• Fly connectome demos aren't what they seem: Beat Saber video is overfit replay, real RL not done yet — dotey · 2026-09-10
• A fly brain can play Beat Saber, larvarl-LVR demo goes viral — avaa411 · 2026-09-11
• Fruit fly brain connectome simulated to play Beat Saber, startling researchers — LinusEkenstam · 2026-09-12

Episode 8 · Fruit Fly Connectome Experiments Raise Consciousness Ethics Concerns (2026-09-11, 3 posts)

While the fruit fly connectome playing Beat Saber was hailed as a landmark demo, commentators warn that such experiments feel unsettling because as capabilities scale up, no force seems likely to stop them even when systems might become conscious.

• Fly connectome experiments spark worry: nothing stops them as systems near consciousness — burny_tech · 2026-09-11
• Fly connectome experiments spark unease about ethics of simulated nervous systems — NathanpmYoung · 2026-09-11
• Fly Brain Connectome Plays Beat Saber, Exposing Holes in Our Intuitions About Sentience — floguo · 2026-09-11

Episode 9 · Fly Brain Connectome Mapped — and Made to Play Smash Bros (2026-09-11, 2 posts)

Google Research and partners mapped the full adult male fruit fly brain—over 166,000 neurons—by stitching millions of 2D images into 3D with AI. A hacker then wired the connectome into a simulator to play Smash Bros.

• Fruit fly connectome wired into Smash Bros: a full brain simulation plays the game — _KevinTang · 2026-09-11
• AI-mapped fruit fly brain (166,000+ neurons) now plays Super Smash Bros Melee on a Mac Studio — TheMoonMidas · 2026-09-11

Episode 10 · Google Maps Complete Male Fruit Fly Brain Connectome (2026-09-13, 4 posts)

Google Research and HHMI Janelia completed the first full connectome of an adult male fruit fly—about 166,000 neurons and 10 million synapses from 100TB of data. The digital fly brain can already perform open-world navigation, with a zebrafish connectome next in line.

• Google and Janelia mapped all 166,000 fruit fly neurons — it played Doom within days — GregCook2011 · 2026-09-13
• Google maps the complete male fruit fly brain, an AI-for-science connectomics milestone — tazecode · 2026-09-13
• AI helps map complete fruit fly brain with 166,000+ neurons reconstructed — wandb · 2026-09-13
• Digital fruit fly brain nails open-world navigation; zebrafish connectome (200TB) underway — max_paperclips · 2026-09-14

Episode 11 · Fruit fly brain connectome wired into walking Strandbeest robot (2026-09-13, 3 posts)

Developers wired a fruit fly whole-brain connectome (166,700 neurons, 25 million connections) into a physical Strandbeest robot, translating simulated neural activity into motor commands that drive its legs — a striking bio-to-robot control experiment.

• Fruit Fly Connectome With 166,700 Neurons Drives a Physical Robot — flngr · 2026-09-13
• Fruit fly brain with 166,700 neurons runs in a physical robot — GregCook2011 · 2026-09-14
• Fruit fly brain with 166,700 neurons installed in a physical robot that walks — udmrzn · 2026-09-15

Episode 12 · Fly Brain Connectome Already Powers Drone Flight Control (2026-09-14, 2 posts)

Weeks after Janelia, MRC LMB, and Google released the MaleCNS v1.0 fruit fly connectome (167k neurons, 25M connections), makers have already used it to control drones and robots in real time.

• Fly brain connectome with 166,700 neurons already powering robots, drones and AR demos — eyishazyer · 2026-09-14
• Full fruit fly brain map, 166,700 neurons, flies a drone in real time — anselm · 2026-09-15