Scientists have completed the first full map of neural connections—called a connectome—in an adult fruit fly, linking the brain and nerve cord for the first time. This comprehensive wiring diagram, published in Nature, reveals that motor control is largely decentralized: movements like walking and flying are managed by local neural circuits in the relevant body parts, rather than being directed entirely by the brain. The discovery challenges a long-standing assumption in neuroscience that the brain acts as a centralized command center for behavior.

The connectome was built by slicing a single fruit fly into thousands of ultra-thin sections and imaging them with electron microscopy. AI tools then reconstructed the images into a detailed 3D map showing individual synapses across the entire central nervous system. The dataset is now publicly available, offering a foundational resource for studying how nervous systems generate complex behaviors.

Researchers say the findings could reshape understanding of motor control across species, including humans. They also suggest new design principles for artificial intelligence, as biological systems like the fruit fly achieve remarkable coordination with minimal hardware. Future work will explore whether similar distributed control exists in more complex animals, such as mice.