scholarly journals Rapid activation of esophageal mechanoreceptors alters the pharyngeal phase of swallow: Evidence for inspiratory activity during swallow

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0248994
Author(s):  
Michael L. Frazure ◽  
Alyssa D. Brown ◽  
Clinton L. Greene ◽  
Kimberly E. Iceman ◽  
Teresa Pitts

Swallow is a complex behavior that consists of three coordinated phases: oral, pharyngeal, and esophageal. Esophageal distension (EDist) has been shown to elicit pharyngeal swallow, but the physiologic characteristics of EDist-induced pharyngeal swallow have not been specifically described. We examined the effect of rapid EDist on oropharyngeal swallow, with and without an oral water stimulus, in spontaneously breathing, sodium pentobarbital anesthetized cats (n = 5). Electromyograms (EMGs) of activity of 8 muscles were used to evaluate swallow: mylohyoid (MyHy), geniohyoid (GeHy), thyrohyoid (ThHy), thyropharyngeus (ThPh), thyroarytenoid (ThAr), cricopharyngeus (upper esophageal sphincter: UES), parasternal (PS), and costal diaphragm (Dia). Swallow was defined as quiescence of the UES with overlapping upper airway activity, and it was analyzed across three stimulus conditions: 1) oropharyngeal water infusion only, 2) rapid esophageal distension (EDist) only, and 3) combined stimuli. Results show a significant effect of stimulus condition on swallow EMG amplitude of the mylohyoid, geniohyoid, thyroarytenoid, diaphragm, and UES muscles. Collectively, we found that, compared to rapid cervical esophageal distension alone, the stimulus condition of rapid distension combined with water infusion is correlated with increased laryngeal adductor and diaphragm swallow-related EMG activity (schluckatmung), and post-swallow UES recruitment. We hypothesize that these effects of upper esophageal distension activate the brainstem swallow network, and function to protect the airway through initiation and/or modulation of a pharyngeal swallow response.

1989 ◽  
Vol 66 (3) ◽  
pp. 1501-1505 ◽  
Author(s):  
G. Insalaco ◽  
G. Sant'Ambrogio ◽  
F. B. Sant'Ambrogio ◽  
S. T. Kuna ◽  
O. P. Mathew

Esophageal electrodes have been used for recording the electromyographic (EMG) activity of the posterior cricoarytenoid muscle (PCA). To determine the specificity of this EMG technique, esophageal electrode recordings were compared with intramuscular recordings in eight anesthetized mongrel dogs. Intramuscular wire electrodes were placed in the right and left PCA, and the esophageal electrode was introduced through the nose or mouth and advanced into the upper esophagus. On direct visualization of the upper airway, the unshielded catheter electrode entered the esophagus on the right or left side. Cold block of the recurrent laryngeal nerve (RLN) ipsilateral to the esophageal electrode was associated with a marked decrease in recorded activity, whereas cold block of the contralateral RLN resulted only in a small reduction in activity. After supplemental doses of anesthesia were administered, bilateral RLN cold block essentially abolished the activity recorded with the intramuscular electrodes as well as that recorded with the esophageal electrode. Before supplemental doses of anesthesia were given, especially after vagotomy, the esophageal electrode, and in some cases the intramuscular electrodes, recorded phasic inspiratory activity not originating from the PCA. Therefore, one should be cautious in interpreting the activity recorded from esophageal electrodes as originating from the PCA, especially in conditions associated with increased respiratory efforts.


1988 ◽  
Vol 65 (1) ◽  
pp. 205-209 ◽  
Author(s):  
D. L. Woodall ◽  
O. P. Mathew

The interaction between CO2 and negative pressure pulses on breathing pattern was investigated in 10 anesthetized, spontaneously breathing rabbits. The upper airway was functionally isolated into a closed system. A servo-respirator triggered by the inspiratory activity of the diaphragm was used to apply pressure pulses of -15 cmH2O to the isolated upper airway in early inspiration while the animal was breathing room air, 100% O2, 6% CO2 in O2, or 9% CO2 in O2. The negative pressure pulses produced a reversible inhibition of inspiration in most trials with resultant increase in inspiratory duration (TI); no change was observed in peak diaphragmatic electromyogram (Dia EMG) or expiratory duration, whereas a decrease was seen in mean inspiratory drive (peak Dia EMG/TI). This prolongation of inspiratory duration and decrease in mean inspiratory drive with negative pressure pulses persisted at higher levels of CO2; the slopes of the test breaths were not significantly different from that of control breaths. These results suggest that upper airway negative pressure pulses are equally effective in altering the breathing pattern at all levels of CO2.


2001 ◽  
Vol 91 (2) ◽  
pp. 897-904 ◽  
Author(s):  
M. H. Stella ◽  
S. J. England

The hypothesis that upper airway (UA) pressure and flow modulate respiratory muscle activity in a respiratory phase-specific fashion was assessed in anesthetized, tracheotomized, spontaneously breathing piglets. We generated negative pressure and inspiratory flow in phase with tracheal inspiration or positive pressure and expiratory flow in phase with tracheal expiration in the isolated UA. Stimulation of UA negative pressure receptors with body temperature air resulted in a 10–15% enhancement of phasic moving-time-averaged posterior cricoarytenoid electromyographic (EMG) activity above tonic levels obtained without pressure and flow in the UA (baseline). Stimulation of UA positive pressure receptors increased phasic moving-time-averaged thyroarytenoid EMG activity above tonic levels by 45% from baseline. The same enhancement of posterior cricoarytenoid or thyroarytenoid EMG activity was observed with the addition of flow receptor stimulation with room temperature air. Tidal volume and diaphragmatic and abdominal muscle activity were unaffected by UA flow and/or pressure, whereas respiratory timing was minimally affected. We conclude that laryngeal afferents, mainly from pressure receptors, are important in modulating the respiratory activity of laryngeal muscles.


1982 ◽  
Vol 52 (2) ◽  
pp. 438-444 ◽  
Author(s):  
O. P. Mathew ◽  
Y. K. Abu-Osba ◽  
B. T. Thach

The effects of change in pharyngeal airway pressure on electromyographic (EMG) activity of a pharyngeal dilating muscle (genioglossus) were investigated in 20 anesthetized rabbits. In vagotomized animals, upper airway loading maneuvers (nasal occlusion) increased the peak inspiratory activity of the genioglossus (GG) muscle on the first occluded breath. In contrast, “unloading” maneuvers (switching from nose to tracheostomy breathing) decreased GG activity. To further characterize the GG response, sustained pressure changes were produced within the isolated upper airway. Negative pressure increased GG activity; positive pressure decreased it. A poststimulus effect consisting of increased GG activity compared with control was seen following both negative- and positive-pressure stimuli. Cyclical pressure changes applied to the isolated upper airway increased the GG activity. These observations indicate the presence of reflex pathways that regulate GG muscle activity in response to upper airway pressure loads. This reflex system appears to play a role in regulating GG activity during tidal breathing and could be important in ensuring pharyngeal airway patency.


1985 ◽  
Vol 58 (2) ◽  
pp. 452-458 ◽  
Author(s):  
K. P. Strohl ◽  
J. M. Fouke

We reasoned that in an isolated sealed upper airway a pressure change would be caused by a change in airway volume. In eight spontaneously breathing anesthetized dogs, we isolated the upper airway by transecting the cervical trachea and sealing it from the lung and from the atmosphere. Pressure changes in this isolated upper airway were studied in relation to respiratory phase as evidenced by alae nasi electromyographic (EMG) activation and tidal volume measured at the distal trachea. A fall in pressure, indicating airway dilation, occurred with each spontaneous respiratory effort. Like the moving average of the alae nasi EMG, the pressure drop reached a peak value early in inspiration, was inhibited by further lung inflation, and was absent during passive mechanical ventilation. End-expiratory tracheal occlusion or vagotomy prolonged and augmented EMG activity and also the inspiratory fall in upper airway pressure. Increased levels of CO2 increased the magnitude of change in pressure during inspiration. An inhibiting effect of lung inflation was present to an equal extent at low and high levels of chemical drive. We show that dilation of the airway is concurrent with upper airway muscle activation during early inspiration, that this dilation increases with increasing chemical drive, and that vagal reflexes during lung inflation inhibit this dilation during the latter half of inspiration.


1983 ◽  
Vol 91 (6) ◽  
pp. 648-652 ◽  
Author(s):  
Daniel J. Blum ◽  
Thomas V. McCaffrey

To define the relationship between central control of upper airway muscles and respiratory muscle function, the electromyographic responses of the dilator nares muscles to stimulation of chemoreceptors and pulmonary receptors were studied in six anesthetized dogs. Only at maximal levels of hypoxia was the inspiratory activity of the dilator nares significantly increased. Hypercapnic stimulation increased the inspiratory activity with each incremental increase in CO2. Pulmonary stretch receptor stimulation produced by lung inflation inhibited dilator nares activity. Pulmonary irritant receptor stimulation by intravenously administered histamine increased dilator nares activity, as did pulmonary J receptor stimulation by the intravenous administration of capsaicin.


1994 ◽  
Vol 76 (6) ◽  
pp. 2656-2662 ◽  
Author(s):  
E. B. Gauda ◽  
T. P. Carroll ◽  
A. R. Schwartz ◽  
P. L. Smith ◽  
R. S. Fitzgerald

To investigate the influence of phasic pulmonary stretch receptors (n = 6) and chemoreceptors (n = 7) on the reflex response of the genioglossus (GG) muscle and diaphragm (DIA) to upper airway (UAW) negative pressure, we measured the response of the GG and DIA electromyogram (EMG) to three challenges: 1) negative pressure applied to the UAW during normoxia and hypercapnia, 2) end-expiratory tracheal occlusion, and 3) application of UAW negative pressure simultaneous with tracheal occlusion in spontaneously breathing tracheotomized anesthetized cats. Peak GG EMG was greatest when UAW negative pressure and end-expiratory tracheal occlusion were combined. No GG EMG activity was seen when UAW negative pressure was applied alone unless the animal was vagotomized or hypercapnic. DIA EMG increased in response to UAW negative pressure combined with occlusion. However, the increase in peak GG EMG was significantly greater than for the DIA with the same challenge. DIA EMG amplitude increased in response to occlusion alone but did not change when UAW negative pressure was applied alone. In the cat, phasic feedback from phasic pulmonary stretch receptors is a potent inhibitor of reflex activation of the GG in response to negative pressure applied to the UAW, which can be overridden by an increase in chemoreceptor drive.


2000 ◽  
Vol 37 (2) ◽  
pp. 197-204 ◽  
Author(s):  
Zekai Yaman ◽  
Mikihiko Kogo ◽  
Hitomi Senoo ◽  
Seiji Iida ◽  
Shoichirou Ishii ◽  
...  

Objective Respiratory-related electromyographic (EMG) activity of the superior pharyngeal constrictor (SPC) muscle was analyzed during the early stage of forced breathing. Design Four adult dogs anesthetized with sodium pentobarbital were used. In the first part of the study, oral and nasal breathing tubes were placed into the respective cavities, and a tracheotomy tube was placed in the second part of the study. Two conditions, the presence (oral-nasal tube breathing) and absence (tracheotomy breathing) of airflow in the upper airway, were achieved in each dog. Following quiet breathing, animals were connected to a closed breathing system, first by an oral-nasal tube and then by a tracheotomy tube. We proposed to induce a forced breathing condition mechanically by using this system for 1 minute. We increased resistance to airflow during forced breathing by means of connecting tubes and a bag. Our aim was not to produce chemical drive but to produce a forced respiration by increasing the resistance to airflow. Tidal volume, breathing frequency, minute volume, chest wall movement, and EMG activity of the SPC muscle were measured and analyzed. Results During quiet breathing through an oral-nasal or tracheotomy tube, low-amplitude EMG activity of the SPC muscle corresponding to the expiratory cycle of the respiration was observed. In both study conditions, phasic expiratory EMG activity increased immediately after the advent of the breathing from the closed system. Tidal volumes and frequencies also increased rapidly during forced breathing. Conclusions An increase in the resistance to airflow increased the activity of the SPC muscle. This augmented respiratory activity probably assists the patency of the upper airway. The augmented respiratory activity was independent of the local reflex pathways. Respiratory-related activity of the SPC muscle may help dilate and stiffen the pharyngeal airway, promoting airway patency.


2020 ◽  
Vol 5 (6) ◽  
pp. 1469-1481 ◽  
Author(s):  
Joseph A. Napoli ◽  
Carrie E. Zimmerman ◽  
Linda D. Vallino

Purpose Craniofacial anomalies (CFA) often result in growth abnormalities of the facial skeleton adversely affecting function and appearance. The functional problems caused by the structural anomalies include upper airway obstruction, speech abnormalities, feeding difficulty, hearing deficits, dental/occlusal defects, and cognitive and psychosocial impairment. Managing disorders of the craniofacial skeleton has been improved by the technique known as distraction osteogenesis (DO). In DO, new bone growth is stimulated allowing bones to be lengthened without need for bone graft. The purpose of this clinical focus article is to describe the technique and clinical applications and outcomes of DO in CFA. Conclusion Distraction can be applied to various regions of the craniofacial skeleton to correct structure and function. The benefits of this procedure include improved airway, feeding, occlusion, speech, and appearance, resulting in a better quality of life for patients with CFA.


2009 ◽  
Vol 18 (1) ◽  
pp. 3-12
Author(s):  
Andrea Vovka ◽  
Paul W. Davenport ◽  
Karen Wheeler-Hegland ◽  
Kendall F. Morris ◽  
Christine M. Sapienza ◽  
...  

Abstract When the nasal and oral passages converge and a bolus enters the pharynx, it is critical that breathing and swallow motor patterns become integrated to allow safe passage of the bolus through the pharynx. Breathing patterns must be reconfigured to inhibit inspiration, and upper airway muscle activity must be recruited and reconfigured to close the glottis and laryngeal vestibule, invert the epiglottis, and ultimately protect the lower airways. Failure to close and protect the glottal opening to the lower airways, or loss of the integration and coordination of swallow and breathing, increases the risk of penetration or aspiration. A neural swallow central pattern generator (CPG) controls the pharyngeal swallow phase and is located in the medulla. We propose that this swallow CPG is functionally organized in a holarchical behavioral control assembly (BCA) and is recruited with pharyngeal swallow. The swallow BCA holon reconfigures the respiratory CPG to produce the stereotypical swallow breathing pattern, consisting of swallow apnea during swallowing followed by prolongation of expiration following swallow. The timing of swallow apnea and the duration of expiration is a function of the presence of the bolus in the pharynx, size of the bolus, bolus consistency, breath cycle, ventilatory state and disease.


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