Meeting Abstract

P2.183  Saturday, Jan. 5  New insights into laryngeal motor patterns generating rat ultrasound vocalizations RIEDE, T; University of Utah, Salt Lake City t.riede@utah.edu

Rodents produce highly variable ultrasound whistles as communication signals unlike many other mammals, who employ flow-induced vocal fold oscillations to produce sound. The function of the laryngeal valve in controlling fundamental frequency features of the whistle sounds across different call types was investigated by recording laryngeal muscle electromyographic activity, subglottal pressure and vocal sound output in awake and spontaneously behaving rats. Subglottal pressure patterns explain only a small amount of the fundamental frequency variations across the rat’s vocal repertoire. However, laryngeal muscle activities are highly stereotypic and call type specific. The ultrasound whistle’s fundamental frequency contour therefore provides insight into the neurophysiological control of the larynx. The data allow also a refinement of a model explaining the rodent whistle mechanism, including a focus on laryngeal and pharyngeal anatomical structures and an explanation of variables affecting fundamental frequency, call duration and sound amplitude.