Fruit flies used to study neural circuits

PASADENA, Calif., March 19 (UPI) -- A U.S. biologist says he has used the behavior of fruit flies to study human behavior and, perhaps, develop new treatments for mental illness.

Professor David Anderson of the California Institute of Technology and a Howard Hughes Medical Institute investigator noticed fruit flies subjected to even gentle wind will assume a defensive position, halting flying until the wind ceases.

Anderson and colleagues subsequently discovered the flies' wind-sensitive neurons exist in the same sensory organ in the flies' antennae as the neurons that process the sound of the song of a potential mate.

The next challenge was determining how the same organ processed two distinct stimuli, leading to two distinct behavioral responses. The team mounted a fly under a very powerful two-photon microscope and cut a hole in the shell covering the fly's brain to observe when any neurons were activated by a particular stimulus.

Simultaneously playing recordings of mating sounds and using a fan to make a breeze, the scientists identified the neurons being activated.

"And it was absolutely obvious that neurons in different regions of the brain were being activated by the sound or activated by the wind, and these regions were different, even if we applied the two stimuli simultaneously," said Anderson

He said the findings have potential application for the treatment of mental illnesses and might target medications to precisely where they are needed, as opposed to treating the brain globally.

The study appears in the journal Nature.