Patterning and Modulation of Song in the Courtship of Drosophila melanogaster

Abstract

The courtship ritual of Drosophila is an ideal system in which to study the relationship between neural circuits and behavior. Song and fly movements serve both as sensory inputs and as quantifiable outputs. Song itself is highly variable, and studying the causes and effects of this variability yields insight into the computations involved in the decision-making process. With a novel behavioral assay, we have conducted simultaneous song and video recordings from a number of different fly strains. Recently developed software for automated song segmentation and video tracking allows us to process a large volume of data and explore a range of parameters relating to song and movement during courtship. By fitting a generalized linear model to the data, we are able to predict song features with surprising accuracy given only a few parameters describing fly movements, and sensory manipulations indicate that vision is an important source of information about these movements. Further investigation shows that male visual cues also play an important role in regulating a number of song parameters, including pulse amplitude and inter-pulse interval (IPI). This pulse amplitude modulation can be triggered either by light alone or by the presence of a female, and targeted thermal activation experiments suggest that it most likely occurs in the thoracic or abdominal ganglia.