Every cell, every connection
139,255neuronsand about 50 million synapses
The brain of an adult female fruit fly was cut into wafer-thin slices and photographed under an electron microscope. From that, the team led by Sven Dorkenwald reconstructed all nerve cells and their chemical connections. The wiring diagram was published in Nature in 2024.
Machine plus human
33person-yearsof manual proofreading, estimated
A computer first split the images into individual cells automatically. Then people checked and corrected the results – by the researchers' estimate about 33 person-years of work. The map stays open for further corrections.
Before, only half a brain
Until then the most complete wiring diagram was the "hemibrain", part of the fly brain with about 20,000 fully captured neurons and 14 million synapses. Now the whole brain is available for the first time.
What the map doesn't show
The wiring diagrams contain only chemical synapses. Other ways nerve cells communicate – such as direct electrical contacts or messengers that act over wide areas – aren't included.
