How Do Houseflies Know Which Direction They Are Flying In?
If you were to spin around a few times with your eyes shut, you would still know which direction you were facing. Scientists do not yet understand how the brain maintains this sense of orientation. In an effort to learn more about how the brain functions in order to maintain a sense of direction, researchers from the Rockefeller University looked at the brains of houseflies.
Scientists have recently identified the neural circuits that are responsible for orienting a housefly’s internal compass. This is the first time such a neural mechanism has been studied in any animal. The researchers were able to find a neural circuit that moves a fly’s internal compass in different directions depending on which direction the fly decides to move. These neurons are called P-ENs and they are interwoven with a fly’s internal compass deep within a fly’s brain.
Researchers decided to conduct an experiment that involved placing houseflies on a thin metal rod so that they could travel along the rod while researchers tracked the fly’s neural activity. When the fly was nudged from one side of the metal bar to the other, the researchers were able to record the fly’s brain activity. When the fly was nudged to one side of the bar its internal compass would move accordingly. Next, the researchers decided to blind the housefly by turning the lights off, creating total darkness. Once the flies could no longer see their surroundings, their P-EN neurons became less active, and the flies temporarily lost a sense of direction. However, just like how humans regain a sense of direction in a dark room, the fly’s P-EN neurons began to update the fly’s compass based on the fly’s movements, instead of visual information. Researchers are now trying to find evidence of P-EN neurons in human beings.
Do you find it surprising that an animal as small as a fly could have a brain advanced enough to regain a sense of orientation in a dark room?