Complete Fruit Fly Nervous System Connectome Released

An international team of scientists has published the first complete wiring map of an adult fruit fly’s central nervous system, revealing that complex behaviors like walking and flying are orchestrated by distributed local circuits rather than a single command center in the brain. The research, led by teams from Harvard Medical School and Princeton University and published on June 8 in the journal Nature, provides an unprecedented resource for studying how brains and bodies work together.

The new map, known as a connectome, details every neural connection, or synapse, between approximately 160,000 neurons in the fruit fly’s brain and its ventral nerve cord, which functions similarly to a spinal cord. This work builds on a previously published connectome of the fly brain alone, completed in 2024, and a separate map of the nerve cord. By bridging these two structures, the researchers created a holistic view of the entire central nervous system.

To construct the connectome, researchers sliced a single fruit fly into thousands of ultrathin sections and used electron microscopy to capture millions of high-resolution images. Artificial intelligence tools then aligned these images to...