Discharge properties of upper airway motor units during wakefulness and sleep

2014 ◽  
pp. 59-75 ◽  
Author(s):  
John Trinder ◽  
Amy S. Jordan ◽  
Christian L. Nicholas
Keyword(s):  
Upper Airway ◽  
Motor Units

scholarly journals Common drive to the upper airway muscle genioglossus during inspiratory loading

2015 ◽  
Vol 114 (5) ◽  
pp. 2883-2892 ◽  
Author(s):  
Michael J. Woods ◽  
Christian L. Nicholas ◽  
John G. Semmler ◽  
Julia K. M. Chan ◽  
Amy S. Jordan ◽  
...  
Keyword(s):  
Upper Airway ◽  
Motor Units ◽  
Quadratic Functions ◽  
Emg Activity ◽  
Respiratory Drive ◽  
Activation Effect ◽  
Single Motor Unit ◽  
Common Drive ◽  
Load Discharge ◽  
Inspiratory Load

Common drive is thought to constitute a central mechanism by which the efficiency of a motor neuron pool is increased. This study tested the hypothesis that common drive to the upper airway muscle genioglossus (GG) would increase with increased respiratory drive in response to an inspiratory load. Respiration, GG electromyographic (EMG) activity, single-motor unit activity, and coherence in the 0–5 Hz range between pairs of GG motor units were assessed for the 30 s before an inspiratory load, the first and second 30 s of the load, and the 30 s after the load. Twelve of twenty young, healthy male subjects provided usable data, yielding 77 pairs of motor units: 2 Inspiratory Phasic, 39 Inspiratory Tonic, 15 Expiratory Tonic, and 21 Tonic. Respiratory and GG inspiratory activity significantly increased during the loads and returned to preload levels during the postload periods (all showed significant quadratic functions over load trials, P < 0.05). As hypothesized, common drive increased during the load in inspiratory modulated motor units to a greater extent than in expiratory/tonic motor units (significant load × discharge pattern interaction, P < 0.05). Furthermore, this effect persisted during the postload period. In conclusion, common drive to inspiratory modulated motor units was elevated in response to increased respiratory drive. The postload elevation in common drive was suggestive of a poststimulus activation effect.

Effect of upper airway negative pressure and lung inflation on laryngeal motor unit activity in rabbit

2002 ◽  
Vol 92 (1) ◽  
pp. 269-278 ◽  
Author(s):  
Stephen Ryan ◽  
Walter T. McNicholas ◽  
Ronan G. O'Regan ◽  
Philip Nolan
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Motor Unit ◽  
Unit Activity ◽  
Negative Pressure ◽  
Upper Airway ◽  
Motor Units ◽  
Laryngeal Nerve ◽  
Lung Inflation ◽  
Inspiratory Activity ◽  
Vagal Bradycardia

10.1152/japplphysiol.00413.2001.—Distortion of the upper airway by negative transmural pressure (UANP) causes reflex vagal bradycardia. This requires activation of cardiac vagal preganglionic neurons, which exhibit postinspiratory (PI) discharge. We hypothesized that UANP would also stimulate cranial respiratory motoneurons with PI activity. We recorded 32 respiratory modulated motor units from the recurrent laryngeal nerve of seven decerebrate paralyzed rabbits and recorded their responses to UANP and to withholding lung inflation using a phrenic-triggered ventilator. The phasic inspiratory ( n = 17) and PI ( n = 5) neurons detected were stimulated by −10 cmH2O UANP and by withdrawal of lung inflation ( P < 0.05, Friedman's ANOVA). Expiratory-inspiratory units ( n = 10) were tonically active but transiently inhibited in postinspiration; this inhibition was more pronounced and prolonged during UANP stimuli and during no-inflation tests ( P < 0.05). We conclude that, in addition to increasing inspiratory activity in the recurrent laryngeal nerve, UANP also stimulates units with PI activity.

Upper airway pressure receptors alter expiratory muscle EMG and motor unit firing

1988 ◽  
Vol 65 (1) ◽  
pp. 210-217 ◽  
Author(s):  
E. van Lunteren ◽  
N. S. Cherniack ◽  
T. E. Dick
Keyword(s):  
Motor Unit ◽  
Unit Activity ◽  
Upper Airway ◽  
Motor Units ◽  
Firing Frequency ◽  
Single Motor Unit ◽  
Expiratory Muscle ◽  
Motor Unit Activity ◽  
Motor Unit Firing ◽  
Respiratory Muscle Activity

To examine the effects of upper airway negative pressure (UAW NP) afferents on respiratory muscle activity during expiration (TE), diaphragm electromyograms (EMG) and triangularis sterni EMG and single motor unit activity were recorded from supine anesthetized tracheotomized cats while they breathed 100% O2. The period of TE during which the diaphragm was electrically active (TE-1) and the period of TE during which the diaphragm was quiescent (TE-2) were both increased with continuous UAW NP (P less than 0.001 and P less than 0.05, respectively), as was TE-1 as a percent of TE (P less than 0.001). Continuous UAW NP reduced peak triangularis sterni EMG (P less than 0.001) and delayed its expiratory onset (P less than 0.005) but did not alter its duration of firing. Changes in triangularis sterni EMG were due to a combination of complete cessation of motor unit activity (2 of 17 motor units), a reduction in mean motor unit firing frequency (P less than 0.02), and a delay in the expiratory onset of motor unit activity (P less than 0.001). Qualitatively similar results were obtained when UAW NP was applied during inspiration only. We conclude that 1) UAW NP has reciprocal stimulatory and inhibitory influences on diaphragm and triangularis sterni muscle electrical activity, respectively, during expiration, and 2) the reductions in triangularis sterni EMG are due to both motor unit derecruitment and a slowing of motor unit firing frequency.

Firing Patterns of Human Genioglossus Motor Units During Voluntary Tongue Movement

2007 ◽  
Vol 97 (1) ◽  
pp. 933-936 ◽  
Author(s):  
E. Fiona Bailey ◽  
Amber D. Rice ◽  
Andrew J. Fuglevand
Keyword(s):  
Firing Rate ◽  
Human Subjects ◽  
Upper Airway ◽  
Motor Units ◽  
Healthy Human ◽  
Single Motor Unit ◽  
Airway Patency ◽  
Tongue Muscle ◽  
Human Tongue ◽  
Tongue Movements

The tongue participates in a range of complex oromotor behaviors, including mastication, swallowing, respiration, and speech. Previous electromyographic studies of the human tongue have focused on respiratory-related tongue muscle activities and their role in maintaining upper airway patency. Remarkably, the activities of human hypoglossal motor units have not been studied during the execution of voluntary maneuvers. We recorded single motor unit activity using tungsten microelectrodes in the genioglossus muscle of 10 healthy human subjects performing both slow tongue protrusions and a static holding maneuver. Displacement of the tongue was detected by an isotonic transducer coupled to the lingual surface through a customized lever arm. For protrusion trials, the firing rate at recruitment was 13.1 ± 3 Hz and increased steeply to an average of 24 ± 6 Hz, often with very modest increases in tongue protrusion. For the static holding task, the average firing rate was 16.1 ± 4 Hz, which is surprisingly high relative to limb motor units. The average coefficient of variation of interspike intervals was ∼20% (range, 10–28%). These are the first recordings of their type obtained in human subjects and provide an initial glimpse into the voluntary control of hypoglossal motoneurons during tongue movements presumably instigated by activity in the motor cortex.

scholarly journals Genioglossus motor unit activity in supine and upright postures in obstructive sleep apnea

SLEEP ◽  
2019 ◽  
Vol 43 (6) ◽  
Author(s):  
Billy L Luu ◽  
Julian P Saboisky ◽  
Rachel A McBain ◽  
John A Trinder ◽  
David P White ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Motor Unit ◽  
Unit Activity ◽  
Upper Airway ◽  
Motor Units ◽  
Healthy Controls ◽  
Quiet Breathing ◽  
Supine Posture ◽  
Obstructive Sleep

Abstract This study investigated whether a change in posture affected the activity of the upper-airway dilator muscle genioglossus in participants with and without obstructive sleep apnea (OSA). During wakefulness, a monopolar needle electrode was used to record single motor unit activity in genioglossus in supine and upright positions to alter the gravitational load that causes narrowing of the upper airway. Activity from 472 motor units was recorded during quiet breathing in 17 males, nine of whom had OSA. The mean number of motor units for each participant was 11.8 (SD 3.4) in the upright and 16.0 (SD 4.2) in the supine posture. For respiratory-modulated motor units, there were no significant differences in discharge frequencies between healthy controls and participants with OSA. Within each breath, genioglossus activity increased through the recruitment of phasic motor units and an increase in firing rate, with an overall increase of ~6 Hz (50%) across both postures and participant groups. However, the supine posture did not lead to compensatory increases in the peak discharge frequencies of inspiratory and expiratory motor units, despite the increase in gravitational load on the upper airway. Posture also had no significant effect on the discharge frequency of motor units that showed no respiratory modulation during quiet breathing. We postulate that, in wakefulness, any increase in genioglossus activity to compensate for the gravitational effects on the upper airway is achieved primarily through the recruitment of additional motor units in both healthy controls and participants with OSA.

scholarly journals P005 The effect of alcohol on the motor control of the genioglossus muscle

2021 ◽  
Vol 2 (Supplement_1) ◽  
pp. A23-A23
Author(s):  
J Avraam ◽  
A Dawson ◽  
C Nicholas ◽  
A Kay ◽  
F O’Donoghue ◽  
...  
Keyword(s):  
Nasal Congestion ◽  
Upper Airway ◽  
Motor Units ◽  
Alcohol Concentration ◽  
Healthy Individuals ◽  
Depressant Effect ◽  
Genioglossus Muscle ◽  
Single Motor Units ◽  
Obstructive Sleep ◽  
Breath Alcohol Concentration

Abstract Rationale Alcohol is recognised to worsen snoring and obstructive sleep apnea (OSA). This effect is thought to be due to alcohol’s depressant effect on upper airway dilator muscles such as the genioglossus, but how alcohol reduces genioglossus activity is unknown. The aim of this study was to investigate alcohol’s effect on genioglossus single motor units (SMUs). Methods Healthy individuals visited the lab on two days (Alcohol: breath alcohol concentration ~0.08% or Placebo). They were instrumented with a nasal mask, 4 intramuscular genioglossus SMU EMG wires and an ear oximeter. They were exposed to 8–12 hypoxia trials (45-60s of 10%O2 followed by one breath of 100%O2) while awake. The SMUs were sorted according to their firing patterns with respect to respiration and were quantified during baseline, hypoxia, hyperoxia and recovery. Results The total number of SMUs recorded at baseline (68 and 67 respectively) and their distribution (ET: 29 vs 22, IP: 5 vs 10, IT: 8 vs 20 and TT: 26 vs 15 respectively) was similar between conditions. The discharge frequency did not differ between conditions (21Hz vs 22.4Hz, p&gt;0.08). There was no difference between placebo and alcohol in the number (101 vs 88 respectively) and distribution (ET: 35 vs 32, IP: 22 vs 16, IT: 14 vs 22 and TT: 30 vs 17 respectively, p&lt;0.05) of SMUs during hypoxia. Afterdischarge following hypoxia was also not different between conditions. Conclusion Alcohol has little effect on genioglossus SMUs and afterdischarge. OSA following alcohol may be related to increased upper airway resistance/nasal congestion.

After-Discharge in the Upper Airway Muscle Genioglossus Following Brief Hypoxia

SLEEP ◽  
2021 ◽  
Author(s):  
Joanne Avraam ◽  
Andrew Dawson ◽  
Nicole Feast ◽  
Feiven Lee Fan ◽  
Monika D Frigant ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Upper Airway ◽  
Motor Units ◽  
Firing Frequency ◽  
Healthy Individuals ◽  
Single Breath ◽  
Single Motor Units ◽  
Persistent Firing ◽  
Respiratory Modulation ◽  
Insight Into

Abstract Study Objectives Genioglossus after-discharge is thought to protect against pharyngeal collapse by minimising periods of low upper airway muscle activity. How genioglossus after-discharge occurs and which single motor units (SMUs) are responsible for the phenomenon are unknown. The aim of this study was to investigate genioglossal after-discharge. Methods During wakefulness, after-discharge was elicited 8-12 times in healthy individuals with brief isocapnic hypoxia (45-60s of 10%O2 in N2) terminated by a single breath of 100% O2. Genioglossus SMUs were designated as firing solely, or at increased rate, during inspiration (Inspiratory phasic [IP] and inspiratory tonic [IT] respectively); solely, or at increased rate, during expiration (Expiratory phasic [EP] or expiratory tonic [ET] respectively) or firing constantly without respiratory modulation (Tonic). SMUs were quantified at baseline, the end of hypoxia, the hyperoxic breath and the following 8 normoxic breaths. Results 210 SMU’s were identified in 17 participants. Genioglossus muscle activity was elevated above baseline for 7 breaths after hyperoxia (p&lt;0.001), indicating a strong after-discharge effect. After-discharge occurred due to persistent firing of IP and IT units that were recruited during hypoxia, with minimal changes in ET, EP or Tonic SMUs. The firing frequency of units that were already active changed minimally during hypoxia or the afterdischarge period (P&gt;0.05). Conclusion That genioglossal after-discharge is almost entirely due to persistent firing of previously silent inspiratory SMUs provides insight into the mechanisms responsible for the phenomenon and supports the hypothesis that the inspiratory and expiratory/tonic motor units within the muscle have idiosyncratic functions.

Laryngeal Manifestations of Autoimmune Diseases

2020 ◽  
Vol 5 (2) ◽  
pp. 439-456
Author(s):  
Jenny L. Pierce
Keyword(s):  
Autoimmune Disease ◽  
Autoimmune Diseases ◽  
Patient Outcomes ◽  
Correct Diagnosis ◽  
Upper Airway ◽  
Clinical Implications ◽  
Laryngeal Function ◽  
The Past ◽  
Referral Practices ◽  
Timely Referral

Purpose This review article provides an overview of autoimmune diseases and their effects on voice and laryngeal function. Method A literature review was conducted in PubMed. Combinations of the following keywords were used: “autoimmune disease and upper airway,” “larynx,” “cough,” “voice,” “dysphonia,” and “dyspnea.” Precedence was given to articles published in the past 10 years due to recent advances in this area and to review articles. Ultimately, 115 articles were included for review. Results Approximately 81 autoimmune diseases exist, with 18 of those highlighted in the literature as having laryngeal involvement. The general and laryngeal manifestations of these 18 are discussed in detail, in addition to the clinical implications for a laryngeal expert. Conclusions Voice, breathing, and cough symptoms may be an indication of underlying autoimmune disease. However, these symptoms are often similar to those in the general population. Appropriate differential diagnosis and timely referral practices maximize patient outcomes. Guidelines are provided to facilitate correct diagnosis when an autoimmune disease is suspected.

Distraction Osteogenesis in the Treatment of Craniofacial Anomalies: Applications and Outcomes

2020 ◽  
Vol 5 (6) ◽  
pp. 1469-1481 ◽  
Author(s):  
Joseph A. Napoli ◽  
Carrie E. Zimmerman ◽  
Linda D. Vallino
Keyword(s):  
Distraction Osteogenesis ◽  
Bone Growth ◽  
Upper Airway ◽  
Craniofacial Anomalies ◽  
Craniofacial Skeleton ◽  
Facial Skeleton ◽  
Psychosocial Impairment ◽  
And Function ◽  
Correct Structure

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.

Swallow Pattern Generator Reconfiguration of the Respiratory Neural Network

2009 ◽  
Vol 18 (1) ◽  
pp. 3-12
Author(s):  
Andrea Vovka ◽  
Paul W. Davenport ◽  
Karen Wheeler-Hegland ◽  
Kendall F. Morris ◽  
Christine M. Sapienza ◽  
...  
Keyword(s):  
Behavioral Control ◽  
Upper Airway ◽  
Pattern Generator ◽  
Breathing Patterns ◽  
Motor Patterns ◽  
Control Assembly ◽  
Pharyngeal Swallow ◽  
Laryngeal Vestibule ◽  
Lower Airways ◽  
Swallow Apnea

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.

Sign in / Sign up

Export Citation Format

Share Document