Social Experience and Auditory Tuning: Uncovering the Effects of Auditory Exposure on the Behavioral and Neural Tuning to Courtship Songs in Drosophila melanogaster

Abstract

Social experience shapes behavior in both vertebrates and invertebrates. In male Drosophila melanogaster flies, the effect of group-housing produces a sharp tuning curve for both behavioral and neural responses to inter-pulse-interval, which are not present in single-housed flies. Inter-pulse-interval (IPI) is an important feature of Drosophila courtship song as it is known to mediate species-species recognition in addition to both female and male arousal. The specific aspect of group-housing that produces the change in auditory tuning in both behavioral and neural responses is still unknown. It is hypothesized that auditory exposure from other males is necessary to produce the sharpening in tuning observed in group-housed settings. Alternatively, because the influence of cross-modal inputs is important for tuning behavior in both vertebrates and Drosophila, it is also hypothesized that sensory inputs outside of the auditory experience contribute significantly to tuning. In order to test these two hypotheses, the behavioral and neural responses to IPI were compared between group-housed flies with wings (WW) and group-housed flies with cut wings (WC) that could not sing. Comparison of GCaMP fluorescence in the pC2 neuron cluster, known to be pulse feature detectors, did not show any significant difference in the shape of responses to IPI for group-housed WW and WC flies. Similarly, there was no difference in the tuning of behavioral responses to IPI for group-housed WW and WC flies. Collectively, the results from this study suggest auditory exposure is not necessary for developing socially-mediated tuning to IPI.