Skip to Main Content

ASHBURN, Va. — Gwyneth Card likes to say that she’s a “fruit fly liberator,” even if she frees her flies with the threat of death from above.

Inside a small, windowless room in Ashburn, Va., she frightens fly after fly into flight. Within a mini IMAX theater, the flies are confronted with a large, dark circle to mimic a damselfly attack. A high-speed camera picks up the daring escape.

Pool tens of thousands of these captured jailbreaks together and you can start to glimpse how the collective fly brain manages an existential threat.


For Card, a group leader at the Janelia Research Campus, scaring flies creates an opportunity to peer inside their minds — and ultimately a path to peering inside our own.

“On the surface it might seem crazy to think that there would be any kind of connection between how a human brain works and how a fly brain works, but if you think about it, they are solving the same problem,” she said.


That problem is how to process the visual world around us. And whether you’re a fly or human, the act of getting away appears to be something that evolution builds in us in just about the same way.

“By going in and understanding the networks of neurons that chose among these actions, we’re actually studying relatively conserved patterns of behavior that might even apply to mammals such as ourselves,” said Card.

Thankfully, the fly brain is easier to work with. That’s due to sheer size (flies have around 300,000 cells, while humans have 90-100 billion cells) and the fact that it’s pretty easy to tweak the genetics of flies, and therefore gain control of different parts of their brains.

Card’s endgame for the fly brain is to plot out the various circuits that control behaviors like escape. If you know how those circuits work, you also know how they can break. And because escape is all about movement, Card thinks that a fly circuit diagram could provide a helpful guide to the shorted circuits in our own complicated heads.

When human brain wiring goes wrong, it leads to neurological diseases, such as Alzheimer’s, epilepsy, and severe migraines.

Card also believes that inside the humble fly lay clues to human wiring fixes. “We think that by using flies to understand the specifics of how these brain computations and pathways work, down the road, that will give us the insights to understand the mechanisms of how things are going wrong in some of these diseases,” she said. “That will eventually be able to lead to treatments.”