Data supporting "Nonlinear processing of a multicomponent communication signal by combination‑sensitive neurons in the anuran inferior colliculus"

This submission is a supplement to the paper entitled "Nonlinear processing of a multicomponent communication signal by combination-sensitive neurons in the anuran inferior colliculus" by Lee et al. (2017) published in the Journal of Comparative Physiology A. We investigated how female green treefrogs (Hyla cinerea) integrate multiple spectral components present in male advertisement calls. Typical calls have a bimodal spectrum consisting of low-frequency (0.9 kHz) and high-frequency (2.7 kHz) components that are transduced by different sensory organs in the inner ear. In behavioral experiments, only bimodal calls reliably elicited phonotaxis in no-choice tests, and they were selectively chosen over unimodal calls in two-alternative choice experiments. Single-unit recordings from the inferior colliculus of awake, passively listening subjects were classified as combination-insensitive (27.9%) or combination-sensitive units (72.1%) based on patterns of relative responses to the same bimodal and unimodal calls. Combination-insensitive units responded similarly to the bimodal call and one or both unimodal calls. In contrast, combination-sensitive units exhibited both linear responses and, more commonly, nonlinear responses to the spectral combination in the bimodal calls. Nonlinearities play potentially critical roles in spectral integration and in the neural processing of multicomponent communication signals. This submission includes source data used in generating the figures presented in the paper.