Behavioral responses to a repetitive shadow stimulus express a persistent state of defensive arousal in Drosophila

William T. Gibson1,2,3, Carlos R. Gonzalez3, Conchi M. Fernandez3, Lakshmi Ramasamy4, Tanya Tabachnik4, Rebecca R. Du2, Panna E. Felsen3, Michael M. Maire3, Pietro Perona3, and David J. Anderson1,2,4 William T. Gibson: wtgibson@caltech.edu; David J. Anderson: wuwei@caltech.edu 1Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA 91125, USA 2Division of Biology & Biological Engineering 156-29, California Institute of Technology, Pasadena, CA 91125, USA