New Discoveries About Traumatic Brain Injuries: Fruit Flies May be Key

Head injuries are associated with some severe complications later in a person's life. Former professional football players, for example, have suffered brain damage and have even committed suicide. Now, scientists have uncovered a little bit more about head injuries, examining fruit flies in order to understand the genetic underpinnings of susceptibility to brain injuries and links to human traumatic brain injury (TBI).

TBIs occur when a force on the body jostles the brain inside a person's head. This causes the brain to strike the inside of the skull. It's estimated that more than 1.7 million TBIs occur each year in the United States; about one-third occur due to falls and the rest are mainly due to car crashes, workplace accidents and sports injuries.

The immediate effects of TBI are usually temporary and mild. People may experience confusion, dizziness or loss of coordination, headaches or vision problems. Over time, though, people may also experience neurodegeneration and related symptoms, including memory loss, cognitive problems, severe depression or Alzheimer's-like dementia.

In order to better understand TBIs, the researchers examined fruit flies. The fly brain is encased in a hard cuticle, similar to a skull. Like with humans, very few flies die from immediate impact. Yet afterward, they show many of the same symptoms as humans who sustain concussions or other TBIs.

"Now we have a system where we can look at the variables that are the inputs into TBI and determine the relative contributions of each to the pathological outcomes," said David Wassarman, one of the researchers, in a news release. "That's the real power of the flies."

From the flies, the scientists discovered that age plays an important role in TBI. Older flies are more susceptible than younger ones to the effects of impact. In addition, many of the outcomes of TBI are very similar to the normal aging processes. With this new model, the scientists should be able to draw on the vast collection of genetic tools and techniques to probe the underlying drivers of damage.

Already, the researchers have identified the crucial role that genetics play in the outcome of an injury. There was a high degree of variability seen among different strains of flies. This discovery may explain why all potential TBI drugs to date have failed in clinical trials despite showing promise in individual rodent models.

"These exciting findings that we can study traumatic brain injury--a disorder of growing concern for athletes, the military and parents--in the elegantly simple model of fruit flies is sure to interest those researchers and companies looking to address this concern," said Jennifer Gottwald, WARF licensing manager, in a news release. "The use of this model can accelerate the work of the medical research community in finding treatments and therapies to help patients."

The findings are published in the journal Proceedings of the National Academy of Sciences.