Effect of Superior Laryngeal Nerve on Vocal Fold Function: An in Vivo Canine Model

1991 ◽  
Vol 105 (6) ◽  
pp. 857-863 ◽  
Author(s):  
David H. Slavit ◽  
Thomas V. Mccaffrey ◽  
Eriko Yanagi
Keyword(s):  
Vocal Fold ◽  
Superior Laryngeal Nerve ◽  
Vocal Folds ◽  
Canine Model ◽  
Electrical Signal ◽  
Laryngeal Nerve ◽  
Airflow Rate ◽  
Cricothyroid Muscle

Assessment of laryngeal framework surgery requires an awareness of the effect of vocal fold mass, stiffness, and position on voice production. The vibratory pattern of the vocal folds during phonation depends on the subglottic pressure as well as the mass and stiffness of the folds. To assess the effect of variations in vocal fold tension with contraction of the cricothyroid muscle on phonation, eight mongrel dog larynges were studied in vivo. Photoglottography, electroglottography, and subglottic pressure were simultaneously recorded as airflow rate and superior laryngeal nerve (SLN) stimulation were varied. Stimulation of the SLN was modified by varying the frequency and voltage of the stimulating electrical signal. Multiple regression analysis of the data revealed a direct relationship between the voltage of SLN stimulation and frequency of vibration (P < 0.001) at constant subglottic pressure. Increases in the stimulating voltage to the SLN also led to an increase in open quotient (p < 0.001), but no statistically significant change in speed quotient, subglottic pressure, or sound intensity. Changing the frequency of SLN stimulation had only a modest effect on the frequency of vibration. These results are consistent with the reported findings of an increase in frequency and open quotient with increased tension in an in vitro canine model. The glottographic measurement open quotient appears to be an estimator of cricothyroid contraction and longitudinal vocal fold tension, and may be clinically applicable to the assessment of superior laryngeal nerve injuries and laryngeal framework procedures.

Function of the Interarytenoid Muscle in a Canine Laryngeal Model

1994 ◽  
Vol 103 (12) ◽  
pp. 975-982 ◽  
Author(s):  
Sina Nasri ◽  
Jody Kreiman ◽  
Pouneh Beizai ◽  
Michael C. Graves ◽  
Joel A. Sercarz ◽  
...  
Keyword(s):  
Fundamental Frequency ◽  
Nerve Stimulation ◽  
Vocal Fold ◽  
Superior Laryngeal Nerve ◽  
Canine Model ◽  
Laryngeal Nerve ◽  
Activity Measurement ◽  
Nerve Branch

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.

Effects of RLN and SLN Stimulation on Glottal Area

1994 ◽  
Vol 110 (4) ◽  
pp. 370-380 ◽  
Author(s):  
Steven Bielamowicz ◽  
Gerald S. Berke ◽  
Deborah Watson ◽  
Bruce R. Gerratt ◽  
Jody Kreiman
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Particle Velocity ◽  
Nerve Stimulation ◽  
Vocal Fold ◽  
Superior Laryngeal Nerve ◽  
Canine Model ◽  
Laryngeal Nerve ◽  
Canine Experiments ◽  
Morphologic Changes

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.

scholarly journals Concurrent YAP/TAZ and SMAD signaling mediate vocal fold fibrosis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ryosuke Nakamura ◽  
Nao Hiwatashi ◽  
Renjie Bing ◽  
Carina P. Doyle ◽  
Ryan C. Branski
Keyword(s):  
Vocal Fold ◽  
Vocal Folds ◽  
Nuclear Accumulation ◽  
Smad Pathway ◽  
Surgical Interventions ◽  
Smad Signaling ◽  
Iatrogenic Damage ◽  
Tgf Β1

AbstractVocal fold (VF) fibrosis is a major cause of intractable voice-related disability and reduced quality of life. Excision of fibrotic regions is suboptimal and associated with scar recurrence and/or further iatrogenic damage. Non-surgical interventions are limited, putatively related to limited insight regarding biochemical events underlying fibrosis, and downstream, the lack of therapeutic targets. YAP/TAZ integrates diverse cell signaling events and interacts with signaling pathways related to fibrosis, including the TGF-β/SMAD pathway. We investigated the expression of YAP/TAZ following vocal fold injury in vivo as well as the effects of TGF-β1 on YAP/TAZ activity in human vocal fold fibroblasts, fibroblast-myofibroblast transition, and TGF-β/SMAD signaling. Iatrogenic injury increased nuclear localization of YAP and TAZ in fibrotic rat vocal folds. In vitro, TGF-β1 activated YAP and TAZ in human VF fibroblasts, and inhibition of YAP/TAZ reversed TGF-β1-stimulated fibroplastic gene upregulation. Additionally, TGF-β1 induced localization of YAP and TAZ in close proximity to SMAD2/3, and nuclear accumulation of SMAD2/3 was inhibited by a YAP/TAZ inhibitor. Collectively, YAP and TAZ were synergistically activated with the TGF-β/SMAD pathway, and likely essential for the fibroplastic phenotypic shift in VF fibroblasts. Based on these data, YAP/TAZ may evolve as an attractive therapeutic target for VF fibrosis.

Effects of Recurrent Laryngeal Nerve Transection and Vagotomy on Respiratory Contraction of the Cricothyroid Muscle

1989 ◽  
Vol 98 (5) ◽  
pp. 373-378 ◽  
Author(s):  
Gayle E. Woodson
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Superior Laryngeal Nerve ◽  
Upper Airway ◽  
Vocal Folds ◽  
Laryngeal Nerve ◽  
Electromyographic Activity ◽  
Airway Occlusion ◽  
Cricothyroid Muscle ◽  
Bilateral Vagotomy ◽  
Posterior Cricoarytenoid

The cricothyroid muscle (CT) appears to be an accessory muscle of respiration. Phasic inspiratory contraction is stimulated by increasing respiratory demand. Reflex activation of the CT may be responsible for the paramedian position of the vocal folds, and hence airway obstruction, in patients with bilateral recurrent laryngeal nerve (RLN) paralysis. Previous research has demonstrated the influence of superior laryngeal nerve (SLN) afferents on CT activity. The present study addresses the effects of vagal and RLN afferents. Electromyographic activity of the CT and right posterior cricoarytenoid muscle was monitored in anesthetized cats during tracheotomy breathing and in response to tracheal or upper airway occlusion in the intact animal. This was repeated following left RLN transection, bilateral vagotomy, and bilateral SLN transection. Vagotomy abolished CT response to tracheal occlusion and markedly reduced the response to upper airway occlusion. Vocal fold position following RLN transection appeared to correlate with CT activity; however, observed changes were minor.

Effect of Tension, Stiffness, and Airflow on Laryngeal Resistance in the in Vivo Canine Model

1993 ◽  
Vol 102 (10) ◽  
pp. 761-768 ◽  
Author(s):  
Steven Bielamowicz ◽  
Joel A. Sercarz ◽  
Gerald S. Berke ◽  
David C. Green ◽  
Jody Kreiman ◽  
...  
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Superior Laryngeal Nerve ◽  
Canine Model ◽  
Laryngeal Nerve ◽  
Tube Model ◽  
Collapsible Tube ◽  
Data Support ◽  
The Relationship ◽  
Laryngeal Resistance

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.

Noncontact Determination of the Mechanical Properties of the Human Vocal Folds

2008 ◽  
Author(s):  
Shinji Deguchi ◽  
Kazutaka Kawashima
Keyword(s):  
Mechanical Properties ◽  
Vocal Fold ◽  
Measurement Techniques ◽  
Voice Quality ◽  
Vocal Folds ◽  
In Vivo Measurement ◽  
In Vitro Measurements ◽  
Excited Oscillation

Mechanical properties of the vocal folds (such as stiffness or viscoelastic properties) play an essential role in phonation. They affect not only voice quality but also onset threshold of vocal fold self-excited oscillation, a sound source of voice [1]. Many experimental data on the mechanical properties have been reported so far, in which in vitro [2] or in vivo measurement techniques [3] were employed. In vitro measurements give us detailed information on the mechanical properties, yet it would be required to consider possible loss of freshness of the specimen. Meanwhile, current in vivo measurement methods utilize a thin probe to deform the vocal fold tissue located at the back of the throat and hence need technical skills for the surveyor to successfully obtain its loading-deformation relationship.

Measurement of Young's Modulus in the in Vivo Human Vocal Folds

1993 ◽  
Vol 102 (8) ◽  
pp. 584-591 ◽  
Author(s):  
Quang T. Tran ◽  
Bruce R. Gerratt ◽  
Gerald S. Berke ◽  
Jody Kreiman
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Young’S Modulus ◽  
Nerve Stimulation ◽  
Vocal Fold ◽  
Young's Modulus ◽  
Vocal Folds ◽  
Laryngeal Nerve ◽  
New Device ◽  
Vocal Fold Vibration

Currently, surgeons have no objective means to evaluate and optimize results of phonosurgery intraoperatively. Instead, they usually judge the vocal folds subjectively by visual inspection or by listening to the voice. This paper describes a new device that measures Young's (elastic) modulus values for the human vocal fold intraoperatively. Physiologically, the modulus of the vocal fold may be important in determining the nature of vocal fold vibration in normal and pathologic states. This study also reports the effect of recurrent laryngeal nerve stimulation on Young's modulus of the human vocal folds, measured by means of transcutaneous nerve stimulation techniques. Young's modulus increased with increases in current stimulation to the recurrent laryngeal nerve. Ultimately, Young's modulus values may assist surgeons in optimizing the results of various phonosurgeries.

Regeneration of Aged Vocal Folds with Basic Fibroblast Growth Factor in a Rat Model: A Preliminary Report

2005 ◽  
Vol 114 (4) ◽  
pp. 304-308 ◽  
Author(s):  
Shigeru Hirano ◽  
Tomoko Tateya ◽  
Hiromi Nagai ◽  
Charles N. Ford ◽  
Ichiro Tateya ◽  
...  
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Lamina Propria ◽  
Basic Fibroblast Growth Factor ◽  
Vocal Fold ◽  
Vocal Folds ◽  
Fibroblast Growth ◽  
Collagen Production

Aged vocal folds have been reported to have dense collagen deposition and decreased hyaluronic acid (HA) in the lamina propria. These characteristics are thought to contribute to vocal problems that occur with age (presbyphonia). To restore better viscoelasticity to aged vocal folds, an intervention that might increase HA and decrease collagen production from aged vocal fold fibroblasts would appear to be a potentially useful approach. Our previous in vitro study has revealed that basic fibroblast growth factor (bFGF) consistently stimulates HA production and decreases collagen production from aged rat vocal fold fibroblasts. The present in vivo study examined the effects of intracordal injection of bFGF into aged rats' vocal folds in terms of restoration of HA and collagen distribution in the lamina propria. We injected bFGF transorally into the lamina propria of (unilateral) vocal folds. The injection was repeated 4 times weekly, and rats were painlessly sacrificed 1 week, 1 month, and 2 months after the final injection. Histologic examination revealed that bFGF significantly increased the HA content of the lamina propria up to 2 months, but showed no effect on collagen, even after 2 months. Because it might take longer for excessive collagen to be degraded, further studies are necessary to clarify the long-term effect on collagen. A drug delivery system for bFGF also needs to be developed to maximize its effect in the future. The present study suggested at least a positive effect of bFGF in restoring the HA content in the aged vocal fold lamina propria.

Functional Differences between the Two Bellies of the Cricothyroid Muscle

1998 ◽  
Vol 118 (5) ◽  
pp. 714-722 ◽  
Author(s):  
Ki Hwan Hong ◽  
MING YE ◽  
Young Mo Kim ◽  
Kevin F. Kevorkian ◽  
Jody Kreiman ◽  
...  
Keyword(s):  
Vocal Fold ◽  
Vocal Folds ◽  
Cricothyroid Muscle ◽  
Functional Differences ◽  
Forward Translation ◽  
Pars Recta ◽  
Vocal Intensity ◽  
Clinically Significant ◽  
Main Factor

The contraction of the cricothyroid (CT) muscle, which results in a decrease in the distance between the thyroid and cricoid cartilages, is considered to be the main factor in lengthening the vocal folds. This is achieved by rotation of the CT joint. The CT muscle is composed of two distinct bellies, the pars recta and the pars obliqua. The function of each subunit is not clearly understood, although it is believed that they act differently because their fibers run in different directions. To clarify the function of the two bellies in phonation, the fundamental frequency (F0), vocal intensity, subglottic pressure, vocal fold length, and CT distance were measured using an in vivo canine laryngeal model. On the basis of these measurements, we demonstrated that the two bellies are varied in their effect on raising the pitch, rotation, and forward translation of the CT joint. The stimulation of the pars recta nerve resulted in a greater increase in the F0 value compared with that of pars obliqua. The combined activity of the pars recta and pars obliqua is important in adjustment of the vocal fold length. The CT approximations directed parallel to the pars recta and pars obliqua simultaneously were more effective in elevation of the pitch than the approximation placed parallel to the pars recta only. This finding may be clinically significant with regard to CT approximation thyroplasty in human trails. (Otolaryngol Head Neck Surg 1998;118:714–22.)

Effect of Subglottic Pressure on Fundamental Frequency of the Canine Larynx with Active Muscle Tensions

1994 ◽  
Vol 103 (10) ◽  
pp. 817-821 ◽  
Author(s):  
Nancy Pearl Solomon ◽  
Kang Liu ◽  
Tzu-Yu Hsiao ◽  
Erich S. Luschei ◽  
Tsu-Ching Fu ◽  
...  
Keyword(s):  
Fundamental Frequency ◽  
Vocal Fold ◽  
Dynamic Stiffness ◽  
Vocal Folds ◽  
Canine Model ◽  
Active Muscle ◽  
Vocal Fold Vibration ◽  
Stiffness Properties ◽  
Stimulation Of

The relation between subglottic pressure and the fundamental frequency of vocal fold vibration was studied by means of evoked phonation in an in vivo canine model. The evoked-phonation model involved electrical stimulation of the midbrain that resulted in consistent responses by respiratory and laryngeal musculature, accompanied by phonation. The dynamic stiffness properties of the vocal folds, especially the “cover,” were investigated by delivering various amounts of air pressure to the larynx from an opening in the trachea. The fundamental frequency of vocal fold vibration increased linearly with subglottic pressure. The slopes ranged from 22.4 to 118.7 Hz per kilopascal in 7 animals. The results indicated that the dependence of fundamental frequency on subglottic pressure is a passive mechanical phenomenon.

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