Evidence of a primitive emotion-like behavior in the fruit fly Drosophila melanogaster has been uncovered by researchers at the California Technical Institute, according to a study published in the December issue of Neuron.
The findings provide new clues into the neurological basis of attention deficit hyperactivity disorder (ADHD).
In the study, which was led by Caltech postdoctoral fellow Tim Lebestky, researchers exposed flies to a series of brief air puffs and identified flies with an abnormally exaggerated hyperactivity response. Genetic studies of flies with an exaggerated response revealed a mutation in a dopamine receptor that produced the aberrant behavior. Flies with the mutation were hypersensitive to the air puffs and took much longer to calm down than flies without the mutation.
The findings that flies exhibit emotion-like behavior that are controlled by some of the same brain chemicals as humans opens up the possibility of applying powerful genetics of this 'model organism' to understand how these chemical influence behavior through their actions on specific brain circuits. While the specific details of where and how this occurs are likely to be different in flies and in humans, the basic principles are likely to be evolutionarily conserved, and may aid in our understanding of what goes wrong in disorders such as ADHD.