Meeting Abstract
P3.148 Thursday, Jan. 6 Vocal tract motor patterns in spontaneously vocalizing rats (Rattus norvegicus) RIEDE, T.*; MA, S.T.; SUTHERS, R.A.; KANE, J.R.; FOX, C.; RAMIG, L.; SCHALLERT, T.; Uni. of Utah, Salt Lake City; Univ. of Michigan, Ann Arbor; Indiana Univ., Bloomington; Univ. of Texas, Austin; Univ. of Colorado, Boulder; Univ. of Colorado, Boulder; Univ. of Texas, Austin t.riede@utah.edu
In human speech, the sound generated by the larynx is modified by articulatory movements of the upper vocal tract, which acts as a variable resonant filter concentrating energy near particular frequencies, essential in speech recognition. Little is known about the presence of variable vocal tract filters in other vertebrates. Through x-ray cinematography of spontaneously vocalizing rats, we investigated whether sound production in rats is accompanied by articulatory movements (mandible, tongue, larynx, hyoid). Rat vocalization represents an important model in clinical research. A rat model of Parkinson’s disease has proven effective for research about therapeutic measures improving locomotion patterns as well as emerging data in ultrasonic vocalization.Parkinson’s disease is accompanied by various motor deficiencies, including deterioration of speech motor patterns. We tested six healthy male rats and six Parkinson’s disease model male rats. Lateral recordings from 6 animals (3 normal, 3 PD-rats) producing 50 kHz calls suggest that a call is accompanied with an expansion of the oral cavity. Lateral video recordings from 7 animals (3 normal, 4 PD-rats) producing 22 kHz calls demonstrated that call production is associated with a simultaneous expansion of an oral and a pharyngo-nasal cavity. No differences between normal and PD-rats could be identified. The stereotypic occurrence of a single chamber expansion during the production of 50 kHz calls and a dual-chamber expansion during 22 kHz call production suggests the existence of articulatory movements. A computational acoustic model suggests that this call-related motor pattern adjusts vocal tract resonance for whistles at the respective frequencies.
