In separate experiments, postdoctoral researcher Hongmei Li-Byarlay and undergraduate student Jonathan Massey found that reduced oxidative phosphorylation in fruit flies also increased aggression. Using advanced fly genetics, the team found this effect only when oxidative phosphorylation was reduced in neurons, but not in neighboring cells known as glia. This result, too, was surprising, since "glia are metabolically very active, and are the energy storehouses of the brain," Robinson said.
The findings offer insight into the immediate and longer-term changes that occur in response to threats, Robinson said.
"When an animal faces a threat, it has an immediate aggressive response, within seconds," Robinson said. But changes in brain metabolism take much longer and cannot account for this immediate response, he said. Such changes likely make individuals more vigilant to subsequent threats.
"This makes good sense in an ecological sense," Robinson said, "because threats often come in bunches."
The fact that the researchers observed these effects in two species that diverged 300 million years ago makes the findings even more compelling, Robinson said.
"Because fruit flies and honey bees are separated by 300 million years of evolution, this is a very robust and well-conserved mechanism," he said.
|Contact: Diana Yates|
University of Illinois at Urbana-Champaign