A Step Closer to Understanding Social Behavior: Social Interactions and Dopamine in Drosophila melanogaster. Robert W. Fernandez¹, Adesanya A Akinleye¹, Marat Nurilov¹, Zulekha Rouzyi¹, Anne F Simon^1,2. 1) School of Arts And Sciences, Department of Biology, The City Univ New York, York College, Jamaica, NY; 2) York College and The Graduate Center, The City University of New York.

   Background: Autistic individuals typically have difficulty with social interactions, including being socially avoidant, indifferent, and awkward, but the underlying causes are not well understood. In addition, there are known variation in the level of dopamine (DA) and serotonin in autistic individuals. We hypothesize that modulating the levels of DA in Drosophila melanogaster will modify its social behavior.
   Methods: We manipulated the expression of the vesicular monoamine transporter (VMAT), through its overexpression (UAS-cDNA) or loss of function (UAS-RNAi) in DArgic cells (Gal4-Th). We also feed drugs known to increase (L-DOPA) or decrease (3-IT) DA content in the adult. We contrasted two different social behavior assays to test the flies response to others: measure of closest neighbor in the Resource Independent Local Enhancement assay (RILE), and innate avoidance of stressed individuals.
   Results: Our data indicates that there is a negative correlation between copies of VMAT in DArgic cells and social space. These results were mimicked in the pharmacology experiments. However, no effect of manipulating VMAT was found in response to stressed flies.
   Conclusion: Flies with increased DA lost a sense of personal boundary and came closer to each other. Flies with decreased DA signaling were socially avoidant since they were responding to stressful social signals, but avoided their neighbor in a stable group. This data indicates that we can use behavioral paradigms in the fruit fly as assays to examine the underlying mechanism of asocial behavior such as what is seen in autism.