Fruit Flies Could Unlock Mystery of Alzheimer's

Scientists look to insects for answers on how human brain forms and retains memories

Mary Saner | Jupiter, Florida 16 March 2010

Photo: Max xx, Flickr Creative Commons

The common fruit fly, Drosophila melanogaster, is one of the most commonly used research animals.

At Scripps Research Institute in Jupiter, Florida, scientists are working to find clues about how the human brain processes memories. Their laboratory test animal is not a chimp or a dog or a rat — animals that we know can remember things — it is the common fruit fly.

"They're relatively simple," Ron Davis says, explaining why the fruit fly's brain has some ideal properties for human brain research. "The brain of the fruit fly has about 100,000 neurons. The brain of a human has about 100 billion neurons, and that's an enormous network of interconnected neurons in the human brain, if one thinks about it. We literally can't wrap our brains around the human brain yet."

Fruit fly training regimen

Davis chairs the Department of Neuroscience at Scripps Florida. He's designed an experiment in which fruit flies are trained to remember an odor associated with an unpleasant electrical shock.

VOA - M. Saner

Dr. Ron Davis says fruit flies have essentially the same genes as humans do, just fewer of them.

It involves a series of Plexiglas tubes which have an electrifiable copper grid on their surfaces. "One puts the fly in these tubes first, passes an odor through the tube," Davis says. "Odor A shocks the animal, mild electric shock." After fresh air has been blown through the tubes to remove any trace of the first odor, a second scent is pumped in.

"Odor B passes through the tube and the animals are not shocked. That's the training where we're hoping the animals will develop an association. They'll learn that one odor is bad because it's been punished in the presence of that odor. And the other odor is okay."