Fruit flies used as models for traumatic brain injury

Scientists at UW-Madison are giving fruit flies brain damage in order to test potential therapies for traumatic brain injury.

A patent in late February was granted for a device used to model TBI in invertebrate models. The Wisconsin Alumni Research Foundation is currently seeking commercial partners to develop this method of drug screening.

Researchers developed a mechanical device that can induce TBI in fruit flies, which respond to impact trauma in “many of the same ways as humans,” according to an info sheet provided by WARF.

Around 100 flies can be loaded into the clear vial portion of the device, which is attached to a baseboard with a long, flexible spring. When the spring is pulled back and released, the vial whips downwards into a rubber pad.

When the flies hit the bottom and sides of the container, they experience brain trauma. The patent application for the device shows it can be adjusted to change the level of impact.

Once the flies have been through the device, researchers can test therapy compounds on them. This achieves two main goals: identifying biological pathways for the effects of TBI, and screening potential therapies for TBI.

The scientists have found that just as with humans, TBI in flies causes neurodegeneration and death, affects sleep patterns, and even alters their immune systems. These outcomes vary depending on age and genotype of the flies, as well as impact strength and interval between impacts.

According to WARF’s info sheet, no therapies for TBI currently exist, despite more than two million cases occurring every year in the United States. The condition is caused by physical impacts, many of which take place in car crashes or sports injuries.

TBI has received increased attention in recent years as research has shed new light on how football players in the NFL are being affected. One study from Reuters found more than 40 percent of retired NFL players exhibited signs of traumatic brain injury.

The cost of treatment and associated lost productivity is estimated at $76 billion in the United States alone.

Therapies for TBI have been elusive, as previous drug candidates tested in standard animal models — mice and rats — have all failed during the clinical trial stage. According to WARF, candidates have failed “due in part to the complex nature of TBI as well as the brain’s elaborate response to injury.”

WARF says as many as 70 percent of all human diseases have parallels in fruit flies, meaning the insects can be used to identify particular disease-related genes.

The lead inventors for the new device are David Wassarman, a pharmacology professor at UW-Madison; and Barry Ganetzky, a professor emeritus who has studied several other diseases and processes using fruit flies.

See more in the WARF info sheet:

See the patent:

–By Alex Moe