INVESTIGADORES
MINDLIN Bernardo Gabriel
artículos
Título:
Frequency modulation during song in a suboscine does not require vocal muscles
Autor/es:
A. AMADOR; F. GOLLER; G. B. MINDLIN
Revista:
JOURNAL OF NEUROPHYSIOLOGY
Editorial:
AMER PHYSIOLOGICAL SOC
Referencias:
Año: 2008
ISSN:
0022-3077
Resumen:
The physiology of sound production insuboscines is poorly investigated. Suboscines are thought to developsong innately unlike the closely related oscines. Comparing phonatorymechanisms might therefore provide interesting insight into the evolutionof vocal learning. Here we investigate sound production andcontrol of sound frequency in the Great Kiskadee (Pitangus sulfuratus)by recording air sac pressure and vocalizations during spontaneouslygenerated song. In all the songs and calls recorded, the modulations ofthe fundamental frequency are highly correlated to air sac pressure. Totest whether this relationship reflects frequency control by changingrespiratory activity or indicates synchronized vocal control, we denervatedthe syringeal muscles by bilateral resection of the tracheosyringealnerve. After denervation, the strong correlation betweenfundamental frequency and air sac pressure patterns remained unchanged.A single linear regression relates sound frequency to air sacpressure in the intact and denervated birds. This surprising lack ofcontrol by syringeal muscles of frequency in Kiskadees, in strongcontrast to songbirds, poses the question of how air sac pressureregulates sound frequency. To explore this question theoretically, weassume a nonlinear restitution force for the oscillating membranefolds in a two mass model of sound production. This nonlinearrestitution force is essential to reproduce the frequency modulations ofthe observed vocalizations.