Next the researchers placed a small black object, roughly the size of a spider, 60 degrees to the right or left of the fly. The flies also would choose a puff-free route if offered, showing that they perceived the puffs as a threat (or at least preferred to avoid them).

The team used puffs of air to simulate a physical threat and found that the flies' walking speed increased after being puffed at. Since fear affects vision across animal species, including humans, the mechanism we found may be active in humans as well,' explained Assistant Professor Masato Tsuji from the Department of Biological Sciences at the University of Tokyo. It appears that a single cluster of 20–30 neurons regulates vision when in a state of fear. 'We discovered a neuronal mechanism by which fear regulates visual aversion in the brains of Drosophila (fruit flies). But what actually makes us avert our gaze from the things we fear? Researchers have found that it may be due to a group of neurons in the brain which regulates vision when feeling afraid.

Next, the team want to find out how these neurons fit into the wider circuitry of the brain so they can ultimately map out how fear controls vision.ĭo you cover your eyes during horror movies? Or perhaps the sight of a spider makes you turn and run? Avoiding looking at things which scare us is a common experience, for humans and animals. Fruit fly brains can offer a useful analogy for larger mammals, so this research may help us better understand our own human reactions to scary situations and phobias. Researchers found that in fruit fly brains, these neurons release a chemical called tachykinin which appears to control the fly's movement to avoid facing a potential threat.

Fly brain dopaminergic neurons