VOA常速英语:Flies Help Understand How Human Brains Work

The last common ancestor of flies and humans lived more than 500 million years ago. But scientists say as both organisms evolved they developed similar strategies to sense movement around them. So - scientists at Stanford University are using flies - in an effort to better understand how the human brain works.

A human brain contains more than 100 billion neurons while the fly’s brain has just 100,000. So it is much easier for scientists to study how a fly reacts to a perceived motion.

To do this, scientists designed a tiny treadmill in the shape of a ball, which a fly attached to a pole can move with its feet in any direction.

A small panoramic screen in front of it displays moving objects, causing the fly to avoid them by moving its feet.

Thomas Clandinin is Associate Professor of Neurobiology at Stanford University:

“By moving the treadmill they tell us what they saw and we can measure the relationship between what they see and what they do by this kind of automatic report," said Clandinin.

In another part of the lab a volunteer is watching the same images while his brain activity is being recorded. Scientists say they were surprised to find that human brains and fly brains both follow the same patterns.

“The basic algorithms that the brain uses to do very fundamental things in vision seem to be very similar," said Clandinin.

Scientists say they are now trying to identify which neurons the flies use to react to perceived motion - looking for a clue to how the human brain processes the same information.

Their ultimate goal is to develop better strategies for helping people with psychiatric and neurological diseases.