These Flies Age Faster After Witnessing Death
Dr. Gendron and Scott Pletcher, who is a biologist at the University of Michigan, discovered how flies deal with mortality unintentionally. They were trying to see whether flies would show a behavioral or physiological response, like a heightened immune system, after being around other flies that had been made sick with a pathogen. “The only types of responses we saw happened after the flies that we infected died,” Dr. Pletcher said.
Dr. Pletcher and Dr. Gendron found that flies that had seen corpses were avoided by other flies, as if they’d been marked by death (how this works is still a mystery). The carcass-viewers also quickly lost stored fat and died sooner than their nontraumatized counterparts.
“Our lab has long been interested in how the brain controls aging,” Dr. Pletcher said, so they decided to dig into how the sensory perception of dead flies was being translated into a shorter life span in living flies.
The two scientists housed living flies in vials with fly cadavers for two days, and tracked their brain activity with a fluorescent green dye. Dissecting these death-exposed flies revealed activity in the ellipsoid body, which integrates sensory information in the brain.
Dr. Gendron and Dr. Pletcher then identified the key neurons in the ellipsoid body. When these were shut off, seeing dead flies did nothing to the life span of the living. When the researchers activated those neuron clusters, flies met their maker sooner, even if they had never been exposed to dead flies.
Source: The New York Times
