Edward Kravitz, PhD
George Packer Berry Professor of Neurobiology
People handle stressful situations in different ways. The holidays, which are often stressful, can lead to aggression in some people. There’s no question that one of the most important issues in our society today is unbridled aggression and violence. You certainly see it when there’s a sale in a downtown store, where people are pushing and shoving their way in and battling for sale items.
My lab studies the fruit fly model of aggression. Male and female fruit flies fight for the same reasons other animals and people do: for territory, for food, and for mates. We’re particularly interested in high-level aggression, where fruit flies are actually duking it out. When fruit flies first meet, they tap each other to find out whether the animal is male or female. If it’s a female, they court; if it’s a male, they fight.
That behavior can accelerate to a higher-level pattern of aggression that we call “lunging,” in which a fruit fly stands on its hind legs, putting its forelegs as high as it can and then striking down on an opponent as hard and as fast as it can. It actually hits pretty hard. The first fly that lunges is 16 times more likely to win the fight and obtain the resource if the opponent runs away. Lunging is shown only by male flies and is required to establish hierarchical relationships. “Boxing" and “tussling" are even higher intensity patterns seen in fights, but these are rare events. We’re using the fruit fly to unravel the neuronal connections that promote or suppress aggressive behavior. This system gives us a handle on high-level aggression and may offer us insight into how it is programmed in the brain.
Our work has relevance to psychiatric disorders such as schizophrenia, where aggression is very common.