How to Map a Fly Brain in 20 Million Easy Steps

An enormous new analysis of the wiring of the fruit fly brain is a milestone for the young field of modern connectomics, scientists say.

The brain of a fruit fly is the size of a poppy seed and about as easy to overlook.

“Most people, I think, don’t even think of the fly as having a brain,” said Vivek Jayaraman, a neuroscientist at the Janelia Research Campus of the Howard Hughes Medical Institute in Virginia. “But, of course, flies lead quite rich lives.”

Flies are capable of sophisticated behaviors, including navigating diverse landscapes, tussling with rivals and serenading potential mates. And their speck-size brains are tremendously complex, containing some 100,000 neurons and tens of millions of connections, or synapses, between them.