Interaction Between Telencephalic Signals and Respiratory Dynamics in Songbirds

Song production in songbirds requires the action and coordination of several motor systems, like the respiratory muscles, the syrinx and the upper vocal tract. In particular, the main temporal features of the song are determined by the respiratory patterns, which are complex and diverse. It is not known how vocal motor control is integrated into the respiratory network. One model proposes that all temporal scales of song emerge from telencephalic nucleus (HVC) of the song system. Alternatively, the generation of respiratory patterns for song could be the result of an interaction between the neural instructions from the song control centers and the respiratory system, such that simple telencephalic signals might drive the nonlinear respiratory network and thus give rise to diverse respiratory patterns of song. We tested the basic assumption of the latter model by electrically stimulating telencephalic song control areas and monitored the temporal structure of the respiratory pattern. We found a strong interaction between the induced activation of song centers and the intrinsic respiratory rhythm. The evoked respiratory patterns are consistent with a nonlinear interaction as proposed by the alternative model. Supported by NIH.