Expiratory-modulated laryngeal motoneurons exhibit a hyperpolarization preceding depolarization during superior laryngeal nerve stimulation in the in vivo adult rat

2012 ◽  
Vol 1445 ◽  
pp. 52-61 ◽  
Author(s):  
Tara G. Bautista ◽  
Qi-Jian Sun ◽  
Paul M. Pilowsky
1994 ◽  
Vol 103 (12) ◽  
pp. 975-982 ◽  
Author(s):  
Sina Nasri ◽  
Jody Kreiman ◽  
Pouneh Beizai ◽  
Michael C. Graves ◽  
Joel A. Sercarz ◽  
...  

The interarytcnoid (IA) muscle has rarely been studied in the living larynx. In this work, the role of the IA muscle in phonation was studied in three dogs by means of an in vivo phonation model. The isolated action of the IA muscle was studied by sectioning and stimulating its nerve branch. As IA activity increased, subglottic pressure increased significantly until a plateau was reached. In the absence of superior laryngeal nerve stimulation, the fundamental frequency rose with increasing IA activity. In the presence of superior laryngeal nerve stimulation, however, no significant change in fundamental frequency was observed with increasing IA activity. Measurement of adductory force demonstrated that the IA muscle adducts primarily the posterior vocal fold. In this canine model, phonation was not possible without IA stimulation, owing to a large posterior glottic chink.


1994 ◽  
Vol 111 (6) ◽  
pp. 807-815 ◽  
Author(s):  
Sina Nasri ◽  
Ali Namazie ◽  
Jody Kreiman ◽  
Joel A. Sercarz ◽  
Bruce R. Gerratt ◽  
...  

Recent evidence suggests that the lung-thorax system functions as a constant pressure source during phonation. However, previous animal models used a constant flow source. This article describes an in vivo canine model that maintains a constant subglottic pressure during phonation to more closely simulate the pulmonary system. At any given subglottic pressure, increasing levels of recurrent laryngeal nerve stimulation resulted in a significant rise in resistance followed by a plateau. Increasing levels of superior laryngeal nerve stimulation, however, produced no significant change in glottal resistance. Three experimental conditions were studied: Normal, unilateral recurrent laryngeal nerve paralysis, and paralysis followed by arytenoid adduction. In normal canines, maximal vocal efficiency values were the highest, indicating the best match between pressure and resistance. The vocal efficiency values were significantly lower in recurrent laryngeal nerve paralysis, indicating pressure-resistance mismatch. Arytenoid adduction increased the maximal vocal efficiency values and decreased the mismatch observed in the paralyzed state. These findings may provide insight into an understanding of normal and pathologic laryngeal behavior.


1989 ◽  
Vol 10 (3) ◽  
pp. 181-187 ◽  
Author(s):  
Gerald S. Berke ◽  
Dennis M. Moore ◽  
Bruce R. Gerratt ◽  
David G. Hanson ◽  
Manuel Natividad

1994 ◽  
Vol 110 (4) ◽  
pp. 370-380 ◽  
Author(s):  
Steven Bielamowicz ◽  
Gerald S. Berke ◽  
Deborah Watson ◽  
Bruce R. Gerratt ◽  
Jody Kreiman

In vivo canine experiments have demonstrated that vocal fold stiffness varies proportionately with changing levels of recurrent laryngeal nerve (RLN) and superior laryngeal nerve (SLN) stimulation. This study evaluated the morphologic changes in the glottis at varying levels of nerve stimulation and the presumed effects on laryngeal air particle velocity. Stroboscopic data from the in vivo canine model of phonation were examined under varying conditions of RLN and SLN stimulation. Computerized analysis of stroboscopic Images was used to reconstruct the glottal area vs. time waveforms. As RLN stimulation increased, glottal area per cycle decreased ( p < 0.05). However, as SLN stimulation increased, glottal area per cycle increased ( p < 0.05). These results support the hypothesis that increasing RLN stimulation at similar levels of SLN stimulation produces an increase in air particle velocity, whereas an increase in SLN stimulation causes a decrease in air particle velocity.


1989 ◽  
Vol 505 (1) ◽  
pp. 149-152 ◽  
Author(s):  
David F. Donnelly ◽  
Anthony L. Sica ◽  
Morton I. Cohen ◽  
Heng Zhang

1993 ◽  
Vol 102 (10) ◽  
pp. 761-768 ◽  
Author(s):  
Steven Bielamowicz ◽  
Joel A. Sercarz ◽  
Gerald S. Berke ◽  
David C. Green ◽  
Jody Kreiman ◽  
...  

This study used an in vivo canine model of phonation to determine the effects of airflow on glottal resistance at low, medium, and high levels of recurrent laryngeal nerve (RLN) and superior laryngeal nerve (SLN) stimulation. Static and dynamic trials of changing airflow were used to study the effects of airflow on glottal resistance during phonation. As reported previously, glottal resistance varies inversely as a function of airflow. Increasing levels of RLN stimulation resulted in a statistically significant increase in glottal resistance for each level of airflow evaluated. Variation in SLN stimulation had no statistically significant effects on the relationship between flow and resistance. At airflow rates greater than 590 milliliters per second (mL/s), glottal resistance approached 0.1 mm Hg per mL/s for all levels of RLN and SLN stimulation tested. These data support the collapsible tube model of phonation.


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