Both biological significance of acoustic signals and functional specificity of brain regions shape auditory brain network in music frogs

The architecture and dynamics of brain networks represent the structural and functional organizational principles underlying all cognitive processes and behavioral outputs, including auditory perception. However, the functional brain network and its relationship to auditory perception in non-human vocalizing animals remain inadequately characterized. To investigate these aspects, we recorded multi-channel electrocorticogram (ECoG) from Emei music frogs (Nidirana daunchina) responding to distinct acoustic stimuli and constructed functional brain networks. In general, graph theoretical analysis revealed that non-congeneric heterospecific calls enhanced clustering coefficients, local efficiency, and global efficiency in the theta band. This indicates that non-congeneric heterospecific calls elicit more pronounced network reorganization compared to other stimuli, including conspecific calls. Across frequency bands, the diencephalon exhibited the highest node strength and betweenness centrality, the telencephalon showed moderate node strength and lowest betweenness, and the mesencephalon displayed the lowest node strength but intermediate betweenness. These patterns align with functional specialization. Furthermore, sex differences emerged in network topology, particularly within theta and beta bands, indicating sexually dimorphic auditory processing strategies. These results imply that music frog auditory perception relies not solely on stable hierarchical pathways but involves dynamic adjustments in network efficiency and functional connectivity based on the biological significance of auditory signals.