New research from Cornell University finds that the visual system, not just chemical receptors, has a significant impact on the social behavior of male fruit flies. The study found that enhanced visual input can override usual social inhibition, which has important implications for understanding similar mechanisms in the human brain, particularly those involved in disorders such as autism and schizophrenia.
Male flies often display antisocial behavior toward other male flies and prefer the company of female flies, which recognize male flies through chemical receptors. However, new research from Cornell University biologists shows that the visual system of fruit flies plays an important role in their social interactions.
The discovery provides new insights into the underlying roots of a variety of social behaviors in humans, including those associated with disorders such as mania and autism.
The paper was recently published in the journal Current Biology.
Many animal species use vision to regulate their social behavior, but the underlying mechanisms are largely unknown. In fruit flies, vision is thought to be used explicitly for motion detection and following, rather than regulating social behavior - but researchers have discovered that this may not be the case.
"In our study, we found that overactivating the visual system overrides the inhibitory effects of chemical signals emitted by male flies, saying to another male fly, 'Well, you know, I'm another male fly, don't mess with me,'" said senior author Nilay Yapici, assistant professor of neurobiology and behavior. "Surprisingly, increasing visual gain in the brain somehow overrides chemical sensory inhibition, attracting male flies to other male flies."
The researchers found that altering GABARAP/GABAA receptor signaling in visual feedback neurons in the male fly brain affects social inhibition in male flies. When GABARAP is knocked out in the visual system, male flies unexpectedly display more courtship behavior toward other male flies.
Researchers have discovered that the genes that control visual neurons in fruit flies are similar to those in the human brain. Reduced GABA signaling in the human brain is associated with social withdrawal characteristic of disorders such as autism and schizophrenia.
"Our findings provide a promising avenue for studying how these proteins regulate social behavior in the mammalian brain and their potential contribution to human psychiatric disorders," said lead author Yuta Mabuchi, Ph.D. '23.
Reference: "Visual feedback neurons fine-tune Drosophila male courtship behavior through GABA-mediated inhibition", Yuta Mabuchi, Xinyue Cui, Lily Xie, Haein Kim, Tianxing Jiang and Nilay Yapici, September 5, 2023, "Current Biology".
DOI:10.1016/j.cub.2023.08.034
Compiled source: ScitechDaily