Scientists Map Full Brain of Adult Male Fruit Fly

A team from Google Research, HHMI Janelia, University of Cambridge, and MRC Laboratory of Molecular Biology announced the complete connectome of an adult male fruit fly on September 3. This map charts over 166,000 neurons and millions of synapses across the brain, optic lobes, and ventral nerve cord, using AI to assemble electron microscope images with human proofreading. It reveals hundreds of sex-specific neuron types explaining courtship and aggression differences, and the public dataset now aids studies on vision, walking, and social behaviors. The achievement, nearly two decades in the making, sets a record as the largest cellular brain map yet.