an international research team has, for the first time, completed a high-precision three-dimensional reconstruction of the entire brain connectome of the adult fruit fly’s central nervous system, marking the birth of the first comprehensive insect neural map. this map provides a systematic analysis of all neurons and their synaptic connections, enabling researchers to precisely trace the pathways by which neural signals propagate from the cerebral cortex to peripheral effectors, thereby shedding light on the underlying neural mechanisms of motor control and behavior generation.
to construct this map, the research team employed focused ion beam scanning electron microscopy (fib‑sem), slicing the brain of a single fruit fly into nanoscale layers and acquiring over 25 million ultra‑high‑resolution images. using deep learning algorithms, they performed image registration, segmentation, and connection identification, ultimately reconstructing a detailed three‑dimensional neural network model comprising approximately 135,000 neurons and tens of millions of synaptic connections.
while conventional wisdom holds that higher cognitive functions rely on unified regulation by the brain’s central regions, the new map reveals a highly modular, distributed processing architecture: for example, the lower‑limb motor circuit operates largely autonomously within the homologous structure of the ventral nerve cord in the spinal cord, with only a few long‑range projections linking different segments to achieve synchronized coordination—rather than being driven directly by commands from the brain.
the researchers note that this cross‑scale imaging and intelligent analysis approach is highly scalable and could be extended to mammalian and even human neuroscience. meanwhile, the fruit fly’s efficient sensor–decision–action feedback loop offers a crucial biological paradigm for designing next‑generation biomimetic robots and low‑power neuromorphic ai architectures.
