Use of electrical vestibular stimulation to alter genioglossal muscle activity in awake cats

2003 ◽  
Vol 13 (1) ◽  
pp. 1-8
Author(s):  
A.R. Anker ◽  
A. Ali ◽  
H.E. Arendt ◽  
S.P. Cass ◽  
L.A. Cotter ◽  
...  

Prior work has shown that the vestibular system contributes to regulating activity of upper airway muscles including the tongue protruder muscle genioglossus. The goal of the present experiments was to determine whether electrical vestibular stimulation could potentially be used to alter genioglossal activity in awake animals. Six adult cats were instrumented for recording of EMG activity from genioglossus, abdominal musculature, and triceps. In addition, a silver ball electrode was implanted on the round window for stimulation of vestibular afferents. Subsequently, stimulation and recordings were conducted while animals were awake. In all cases, stimulation using single shocks or trains of pulses > 100 μA in intensity produced responses in all muscles, including genioglossus. The latency of the genioglossal response was approximately 12 msec, and delivering continuous current trains to the labyrinth chronically elevated the muscle's activity. Although a number of muscles were affected by the stimulus, animals experienced no obvious distress or balance disturbances. Vestibular stimulation remained effective in producing genioglossal responses until experiments were discontinued 1–2 months following onset. These data suggest that electrical vestibular stimulation could potentially be used therapeutically to alter upper airway muscle activity.

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.


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.


1991 ◽  
Vol 71 (4) ◽  
pp. 1231-1236 ◽  
Author(s):  
E. B. Gauda ◽  
J. L. Carroll ◽  
S. McColley ◽  
P. L. Smith

We investigated the effect of different levels of O2 tension (hypoxia, normoxia, and hyperoxia) on the breath-by-breath onset and peak electromyographic (EMG) activity of the genioglossus (GG) muscle during a five-breath end-expiratory tracheal occlusion of 20- to 30-s duration. GG and diaphragmatic (DIA) EMG activity were measured with needle electrodes in eight anesthetized tracheotomized adult cats. In response to occlusion, the increase in the number of animals with GG EMG activity was different during hypoxia, normoxia, and hyperoxia (P = 0.003, Friedman). During hypoxia, eight of eight of the animals had GG EMG activity by the third occluded effort. In contrast, during normoxia, only four of eight and, during hyperoxia, only three of eight animals had GG EMG activity throughout the entire five-breath occlusion. Similarly, at release of the occlusion, more animals had persistent GG EMG activity on the postocclusion breaths during hypoxia than during normoxia or hyperoxia. Breath-by-breath augmentation of peak amplitude of the GG and DIA EMGs on each occluded effort was accentuated during hypoxia (P less than 0.01) and abolished during hyperoxia (P = 0.10). These results suggest that hypoxemia is a major determinant of the rapidity of onset, magnitude, and sustained activity of upper airway muscles during airway occlusion.


2003 ◽  
Vol 95 (1) ◽  
pp. 97-103 ◽  
Author(s):  
Pierre-Hugues Fortier ◽  
Philippe Reix ◽  
Julie Arsenault ◽  
Dominique Dorion ◽  
Jean-Paul Praud

We tested the hypotheses that active upper airway closure during induced central apneas in nonsedated lambs 1) is complete and occurs at the laryngeal level and 2) is not due to stimulation of the superior laryngeal nerves (SLN). Five newborn lambs were surgically instrumented to record thyroarytenoid (TA) muscle (glottal constrictor) electromyographic (EMG) activity with supra- and subglottal pressures. Hypocapnic and nonhypocapnic central apneas were induced before and after SLN sectioning in the five lambs. A total of 174 apneas were induced, 116 before and 58 after sectioning of the internal branch of the SLN (iSLN). Continuous TA EMG activity was observed in 88% of apneas before iSLN section and in 87% of apneas after iSLN section. A transglottal pressure different from zero was observed in all apneas with TA EMG activity, with a mean subglottal pressure of 4.3 ± 0.8 cmH2O before and 4.7 ± 0.7 cmH2O after iSLN section. Supraglottal pressure was consistently atmospheric. Sectioning of both iSLNs had no effects on the results. We conclude that upper airway closure during induced central apneas in lambs is active, complete, and occurs at the glottal level only. Consequently, a positive subglottal pressure is maintained throughout the apnea. Finally, this complete active glottal closure is independent from laryngeal afferent innervation.


1984 ◽  
Vol 56 (3) ◽  
pp. 746-752 ◽  
Author(s):  
E. van Lunteren ◽  
W. B. Van de Graaff ◽  
D. M. Parker ◽  
J. Mitra ◽  
M. A. Haxhiu ◽  
...  

The effects of negative pressure applied to just the upper airway on nasal and laryngeal muscle activity were studied in 14 spontaneously breathing anesthetized dogs. Moving average electromyograms were recorded from the alae nasi (AN) and posterior cricoarytenoid (PCA) muscles and compared with those of the genioglossus (GG) and diaphragm. The duration of inspiration and the length of inspiratory activity of all upper airway muscles was increased in a graded manner proportional to the amount of negative pressure applied. Phasic activation of upper airway muscles preceded inspiratory activity of the diaphragm under control conditions; upper airway negative pressure increased this amount of preactivation. Peak diaphragm activity was unchanged with negative pressure, although the rate of rise of muscle activity decreased. The average increases in peak upper airway muscle activity in response to all levels of negative pressure were 18 +/- 4% for the AN, 27 +/- 7% for the PCA, and 122 +/- 31% for the GG (P less than 0.001). Rates of rise of AN and PCA electrical activity increased at higher levels of negative pressure. Nasal negative pressure affected the AN more than the PCA, while laryngeal negative pressure had the opposite effect. The effects of nasal negative pressure could be abolished by topical anesthesia of the nasal passages, while the effects of laryngeal negative pressure could be abolished by either topical anesthesia of the larynx or section of the superior laryngeal nerve. Electrical stimulation of the superior laryngeal nerve caused depression of AN and PCA activity, and hence does not reproduce the effects of negative pressure.(ABSTRACT TRUNCATED AT 250 WORDS)


1989 ◽  
Vol 66 (3) ◽  
pp. 1328-1335 ◽  
Author(s):  
G. Cohen ◽  
D. J. Henderson-Smart

Submental electromyorgams (SM EMG) were recorded from 20 preterm babies (gestational age 30 +/- 2 wk, postmenstrual age at study 35 +/- 2 wk) (mean +/- SD) and 3 full-term infants (7–14 days old). SM EMG was evaluated during eupnea and brief experimental airway occlusion. Phasic inspiratory SM EMG was rarely seen during eupnea. SM EMG tended to increase on the first occluded effort, although this increase was not statistically significant in most babies. All infants showed progressive breath-by-breath augmentation of phasic SM EMG during occlusions in rapid-eye-movement (REM) as well as quiet (QS) sleep; phasic increases in SM EMG were similar during REM and QS occlusions in the majority (16/22) of babies. Periods of airway closure were detected during 24 occlusions in 5 infants; phasic SM EMG was reduced on these occasions. The results are consistent with the idea that recruitment of upper airway muscles contributes to the stability of the airway of the preterm human.


2011 ◽  
Vol 110 (1) ◽  
pp. 69-75 ◽  
Author(s):  
S. Cheng ◽  
J. E. Butler ◽  
S. C. Gandevia ◽  
L. E. Bilston

The electromyographic (EMG) activity of human upper airway muscles, particularly the genioglossus, has been widely measured, but the relationship between EMG activity and physical movement of the airway muscles remains unclear. We aimed to measure the motion of the soft tissues surrounding the airway during normal and loaded inspiration on the basis of the hypothesis that this motion would be affected by the addition of resistance to breathing during inspiration. Tagged MR imaging of seven healthy subjects was performed in a 3-T scanner. Tagged 8.6-mm-spaced grids were used, and complementary spatial modulation of magnetization images were acquired beginning ∼200 ms before inspiratory airflow. Deformation of tag line intersections was measured. The genioglossus moved anteriorly during normal and loaded inspiration, with less movement during loaded inspiration. The motion of tissues at the anterior border of the upper airway was nonuniform, with larger motions inferiorly. At the level of the soft palate, the lateral dimension of the airway decreased significantly during loaded inspiration (−0.15 ± 0.09 and −0.48 ± 0.09 mm during unloaded and loaded inspiration, respectively, P < 0.05). When resistance to inspiratory flow was added, genioglossus motion and lateral dimensions of the airway at the level of the soft palate decreased. Our results suggest that genioglossus motion begins early to dilate the airway prior to airflow and that inspiratory loading reduces the anterior motion of the genioglossus and increases the collapse of the lateral airway walls at the level of the soft palate.


1989 ◽  
Vol 66 (2) ◽  
pp. 755-758 ◽  
Author(s):  
L. G. Olson ◽  
L. G. Ulmer ◽  
N. A. Saunders

This study sought to assess the effect of variations in upper airway muscle activity on upper airway pressure-volume properties. Upper airway elastance, closing pressure, and reserve volume were measured in the isolated upper airways of anesthetized rabbits under control conditions and after administration of gallamine (2 mg/kg iv) or after 10 min of spontaneous respiration of 7% CO2 in O2. Administration of gallamine to seven animals was associated with a fall in reserve volume from 0.94 +/- 0.24 to 0.69 +/- 0.17 (95% confidence interval) ml (P less than 0.01) and of closing pressure from -7.53 +/- 0.23 to -5.75 +/- 1.05 cmH2O (P less than 0.01), but airway elastance did not change significantly. Hypercapnia in seven animals was associated with a rise in elastance from 7.06 +/- 0.91 to 7.67 +/- 0.86 cmH2O/ml (P less than 0.001) and in reserve volume from 0.68 +/- 0.06 to 0.86 +/- 0.13 ml (P less than 0.05). Closing pressure also changed from -5.88 +/- 0.94 to -7.92 +/- 1.85 cmH2O. This change was correlated with the change in reserve volume but not with the change in elastance. In three animals exposed to hypercapnia, return to room air breathing was associated with return of elastance, reserve volume, and closing pressure to control levels. It is concluded that muscle activity in the upper airway affects both the size and elastance of the airway, but the dominant mechanism by which upper airway muscles increase the resistance of the upper airway to collapse is by increasing airway volume.


1998 ◽  
Vol 84 (5) ◽  
pp. 1701-1706 ◽  
Author(s):  
Yong-Xin Shi ◽  
Margaret Seto-Poon ◽  
John R. Wheatley

Exercise (Ex) and hypercapnia (HC) both lead to increases in ventilation and upper airway muscle (UAM) activity. To determine whether different breathing routes (nasal vs. oral) or stimuli produced differential UAM activation, electromyographic (EMG) activity of the alae nasi (AN) and genioglossus (GG) were measured in seven normal subjects seated on a bicycle ergometer. Subjects performed paired runs during both progressive Ex and HC while breathing through the nose alone (N) or the mouth alone (O). During hyperpnea, AN EMG was greater when the subjects were breathing via N [81 ± 6% maximum (HC) and 69 ± 7% maximum (Ex)] than when they were breathing via O [30 ± 5% maximum (HC) and 27 ± 5% maximum (Ex); both P < 0.01], whereas the GG EMG did not differ between N and O. Both AN and GG EMG were similar for Ex and HC when the subjects were breathing via the same route. We conclude that UAM activation was independent of the nature of the stimulus. However, the AN muscle but not the GG muscle demonstrated breathing-route dependence of activity.


1987 ◽  
Vol 63 (2) ◽  
pp. 603-608 ◽  
Author(s):  
D. W. Hudgel ◽  
M. Mulholland ◽  
C. Hendricks

The purposes of this study were 1) to characterize the immediate inspiratory muscle and ventilation responses to inspiratory resistive loading during sleep in humans and 2) to determine whether upper airway caliber was compromised in the presence of a resistive load. Ventilation variables, chest wall, and upper airway inspiratory muscle electromyograms (EMG), and upper airway resistance were measured for two breaths immediately preceding and immediately following six applications of an inspiratory resistive load of 15 cmH2O.l–1 X s during wakefulness and stage 2 sleep. During wakefulness, chest wall inspiratory peak EMG activity increased 40 +/- 15% (SE), and inspiratory time increased 20 +/- 5%. Therefore, the rate of rise of chest wall EMG increased 14 +/- 10.9% (NS). Upper airway inspiratory muscle activity changed in an inconsistent fashion with application of the load. Tidal volume decreased 16 +/- 6%, and upper airway resistance increased 141 +/- 23% above pre-load levels. During sleep, there was no significant chest wall or upper airway inspiratory muscle or timing responses to loading. Tidal volume decreased 40 +/- 7% and upper airway resistance increased 188 +/- 52%, changes greater than those observed during wakefulness. We conclude that 1) the immediate inspiratory muscle and timing responses observed during inspiratory resistive loading in wakefulness were absent during sleep, 2) there was inadequate activation of upper airway inspiratory muscle activity to compensate for the increased upper airway inspiratory subatmospheric pressure present during loading, and 3) the alteration in upper airway mechanics during resistive loading was greater during sleep than wakefulness.


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