Effects of dopamine, isoproterenol, and lobeline on cranial and phrenic motoneurons

1984 ◽  
Vol 56 (3) ◽  
pp. 737-745 ◽  
Author(s):  
E. van Lunteren ◽  
M. A. Haxhiu ◽  
J. Mitra ◽  
N. S. Cherniack
Keyword(s):  
Carotid Body ◽  
Phrenic Nerve ◽  
Hypoglossal Nerve ◽  
Upper Airway ◽  
Excitatory Input ◽  
Peripheral Chemoreceptor ◽  
Laryngeal Nerves ◽  
Body Activity ◽  
Recurrent Laryngeal Nerves ◽  
Upper Airway Muscles

Recent studies have suggested that the upper airway muscles receive a substantial portion of their excitatory input from the peripheral chemoreceptors. We examined the responses of the phrenic, hypoglossal, and recurrent laryngeal nerves to agents that are known to modify carotid body activity. Dopamine, an inhibitor, and isoproterenol and lobeline, two stimulators of carotid body activity, were administered into the lingual arteries of 14 anesthetized, paralyzed cats artificially ventilated with 100% O2. Dopamine decreased the activity of all three nerves (P less than 0.001) but inhibited the hypoglossal nerve more than the phrenic and recurrent laryngeal nerves (P less than 0.001). Isoproterenol and lobeline increased the activity of all three nerves (P less than 0.001) but stimulated the hypoglossal nerve more than the phrenic and recurrent laryngeal nerves (P less than 0.001). These relatively greater effects of all three agents on the hypoglossal nerve compared with the phrenic and the recurrent laryngeal nerves persisted under both hypoxic and hypercapnic conditions. After midcervical vagotomy, the responses of the hypoglossal to all three drugs remained larger than those of the phrenic nerve. After combined vagotomy and carotid sinus nerve section, the stimulatory effects of lobeline and the inhibitory effects of dopamine were no longer apparent. We conclude that it is possible to preferentially alter respiratory-related activity of the hypoglossal nerve compared with that of the phrenic nerve using agents that modify peripheral chemoreceptor activity.

Effect of chemical stimuli on nerves supplying upper airway muscles

1982 ◽  
Vol 52 (3) ◽  
pp. 530-536 ◽  
Author(s):  
D. Weiner ◽  
J. Mitra ◽  
J. Salamone ◽  
N. S. Cherniack
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Phrenic Nerve ◽  
Hypoglossal Nerve ◽  
Cranial Nerves ◽  
Upper Airway ◽  
Laryngeal Nerve ◽  
Nerve Activity ◽  
Phrenic Nerve Activity ◽  
Chemical Stimuli ◽  
Upper Airway Muscles

Studies of upper airway resistance suggest that the activity of cranial nerves supplying upper airway muscles changes with chemical drive and that imbalances in the activation of these nerves as compared to the phrenic play a role in causing upper airway obstruction. We assessed the effect of hypoxia and hypercapnia on the activity of the hypoglossal nerve, the recurrent laryngeal nerve, and phrenic nerve in paralyzed anesthetized artificially ventilated dogs. Comparison of hypoglossal and phrenic nerves were also repeated after vagotomy. Both hypoglossal and recurrent laryngeal nerves exhibited increased activity with inspiration. Hypoxia and hypercapnia increased phrenic nerve activity as well as the activity of the two cranial nerves. While linear increases occurred in phrenic and recurrent laryngeal nerve activity with both chemical stimuli, the relationship between hypoglossal and phrenic nerve activity was curvilinear. At lower levels of chemical drive, changes in hypoglossal nerve were less than in the phrenic, and the reverse was true at higher levels of chemical stimulation. There were also differences in the response of both cranial nerves and the phrenic to changing vagal stimulation. The dissimilarities observed in the cranial response of the nerves (versus the phrenic) could potentially affect the forces developed during inspiration and lead to obstruction in the upper airway.

Upper airway muscle and diaphragm responses to hypoxia in the piglet

1990 ◽  
Vol 68 (2) ◽  
pp. 672-677 ◽  
Author(s):  
R. J. Martin ◽  
E. van Lunteren ◽  
M. A. Haxhiu ◽  
W. A. Carlo
Keyword(s):  
Muscle Activation ◽  
Upper Airway ◽  
Peripheral Chemoreceptor ◽  
Initial Transient ◽  
Central Inhibition ◽  
Muscle Groups ◽  
Posterior Cricoarytenoid ◽  
Upper Airway Muscles ◽  
Spontaneously Breathing ◽  
Ventilatory Response To Hypoxia

The neonatal ventilatory response to hypoxia is characterized by initial transient stimulation and subsequent respiratory depression. It is unknown, however, whether this response is also exhibited by the upper airway muscles that regulate nasal, laryngeal, and pharyngeal patency. We therefore compared electromyogram (EMG) amplitudes and minute EMGs for the diaphragm (DIA), alae nasi (AN), posterior cricoarytenoid (PCA), and genioglossus (GG) muscles in 12 anesthetized spontaneously breathing piglets during inhalation of 12% O2 over 10 min. Minute EMG for the DIA responded to hypoxia with an initial transient increase and subsequent return to prehypoxia levels by 10 min. Hypoxia also stimulated all three upper airway muscles. In contrast to the DIA EMG, however, AN, PCA, and GG EMGs all remained significantly above prehypoxia levels after 10 min of hypoxia. We have thus demonstrated that the initial stimulation and subsequent depression of the DIA EMG after 12% O2 inhalation contrast with the sustained increase in AN, PCA, and GG EMGs during hypoxia. We speculate that 1) central inhibition during neonatal hypoxia is primarily distributed to the motoneuron pools regulating DIA activation and 2) peripheral chemoreceptor stimulation and/or central disinhibition induced by hypoxia preferentially influence those motoneuron pools that regulate upper airway muscle activation, causing the different hypoxic responses of these muscle groups in the young piglet.

Phasic volume-related feedback on upper airway muscle activity

1984 ◽  
Vol 56 (3) ◽  
pp. 730-736 ◽  
Author(s):  
E. van Lunteren ◽  
K. P. Strohl ◽  
D. M. Parker ◽  
E. N. Bruce ◽  
W. B. Van de Graaff ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Phrenic Nerve ◽  
Muscle Activity ◽  
Moving Average ◽  
Upper Airway ◽  
Single Breath ◽  
Early Peak ◽  
Posterior Cricoarytenoid ◽  
Upper Airway Muscles ◽  
Spontaneously Breathing

The effects of vagally mediated volume-related feedback on the activity of upper airway muscles was assessed in nine pentobarbital-anesthetized, tracheostomized, spontaneously breathing dogs. Moving average electrical activity was recorded before and during single-breath airway occlusions from the genioglossus, posterior cricoarytenoid, and alae nasi muscles and compared with simultaneously recorded tidal volume and electrical activity of the phrenic nerve (6 dogs) or diaphragm (3 dogs). The normally early peak of upper airway muscle activity during unoccluded breaths was delayed to late or end inspiration during occluded breaths. Inspiratory depression started at a lower volume above end-expiratory volume and at an earlier time after inspiratory onset for the upper airway muscles than for the phrenic nerve and the diaphragm. The amount of depression at the end of inspiratory airflow was larger for all of the upper airway muscles than for the phrenic nerve and diaphragm. Depressive effects were most prominent in the genioglossus, followed by the posterior cricoarytenoid and the alae nasi. After vagotomy, depressive effects of volume-related feedback were no longer seen. These results suggest that activity of the upper airway muscles is modulated by vagally mediated feedback, apparently to a larger extent than that of the diaphragm and phrenic nerve.

Motor responses to positive-pressure breathing in the developing opossum

1985 ◽  
Vol 58 (5) ◽  
pp. 1489-1495 ◽  
Author(s):  
J. P. Farber
Keyword(s):  
Airway Resistance ◽  
Upper Airway ◽  
Abdominal Muscle ◽  
Positive Pressure ◽  
Postnatal Life ◽  
Abdominal Muscles ◽  
Upper Airways ◽  
Motor Responses ◽  
Upper Airway Resistance ◽  
Upper Airway Muscles

The suckling opossum exhibits an expiration-phased discharge in abdominal muscles during positive-pressure breathing (PPB); the response becomes apparent, however, only after the 3rd-5th wk of postnatal life. The purpose of this study was to determine whether the early lack of activation represented a deficiency of segmental outflow to abdominal muscles or whether comparable effects were observed in cranial outflows to muscles of the upper airways due to immaturity of afferent and/or supraspinal pathways. Anesthetized suckling opossums between 15 and 50 days of age were exposed to PPB; electromyogram (EMG) responses in diaphragm and abdominal muscles were measured, along with EMG of larynx dilator muscles and/or upper airway resistance. In animals older than approximately 30 days of age, the onset of PPB was associated with a prolonged expiration-phased EMG activation of larynx dilator muscles and/or decreased upper airway resistance, along with expiratory recruitment of the abdominal muscle EMG. These effects persisted as long as the load was maintained. Younger animals showed only those responses related to the upper airway; in fact, activation of upper airway muscles during PPB could be associated with suppression of the abdominal motor outflow. After unilateral vagotomy, abdominal and upper airway motor responses to PPB were reduced. The balance between PPB-induced excitatory and inhibitory or disfacilitory influences from the supraspinal level on abdominal motoneurons and/or spinal processing of information from higher centers may shift toward net excitation as the opossum matures.

scholarly journals Histochemical properties of upper airway muscles: comparison of dilator and nondilator muscles

1997 ◽  
Vol 10 (5) ◽  
pp. 990-993 ◽  
Author(s):  
A. Bracher ◽  
R. Coleman ◽  
R. Schnall ◽  
A. Oliven
Keyword(s):  
Upper Airway ◽  
Upper Airway Muscles

Effects of pharyngeal lubrication on the opening of obstructed upper airway

1992 ◽  
Vol 72 (6) ◽  
pp. 2311-2316 ◽  
Author(s):  
H. Miki ◽  
W. Hida ◽  
Y. Kikuchi ◽  
T. Chonan ◽  
M. Satoh ◽  
...  
Keyword(s):  
Hypoglossal Nerve ◽  
Muscle Tone ◽  
Upper Airway ◽  
Intraluminal Pressure ◽  
Lower Airway ◽  
Before And After ◽  
Airway Opening ◽  
Cervical Trachea ◽  
Artificial Surfactant ◽  
Stimulation Of

We examined the effect of electrical stimulation of the hypoglossal nerve and pharyngeal lubrication with artificial surfactant (Surfactant T-A) on the opening of obstructed upper airway in nine anesthetized supine dogs. The upper airway was isolated from the lower airway by transecting the cervical trachea. Upper airway obstruction was induced by applying constant negative pressures (5, 10, 20, and 30 cmH2O) on the rostral cut end of the trachea. Peripheral cut ends of the hypoglossal nerves were electrically stimulated by square-wave pulses at various frequencies from 10 to 30 Hz (0.2-ms duration, 5–7 V), and the critical stimulating frequency necessary for opening the obstructed upper airway was measured at each driving pressure before and after pharyngeal lubrication with artificial surfactant. The critical stimulation frequency for upper airway opening significantly increased as upper airway pressure became more negative and significantly decreased with lubrication of the upper airway. These findings suggest that greater muscle tone of the genioglossus is needed to open the occluded upper airway with larger negative intraluminal pressure and that lubrication of the pharyngeal mucosa with artificial surfactant facilitates reopening of the upper airway.

Obstructive Sleep Apnea: Epidemiology, Causes, and Consequences

2020 ◽  
Author(s):  
Diane C Lim ◽  
Richard J Schwab
Keyword(s):  
Risk Factors ◽  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Cushing Syndrome ◽  
Upper Airway ◽  
Fat Distribution ◽  
Epidemiologic Studies ◽  
Obstructive Sleep ◽  
Upper Airway Muscles ◽  
Underlying Diseases

As part one of the three chapters on sleep-disordered breathing, this chapter reviews obstructive sleep apnea (OSA) epidemiology, causes, and consequences. When comparing OSA prevalence between 1988 to 1994 and 2007 to 2010, we observe that OSA is rapidly on the rise, paralleling increasing rates in obesity. Global epidemiologic studies indicate that there are differences specific to ethnicity with Asians presenting with OSA at a lower body mass index than Caucasians. We have learned that structural and physiologic factors increase the risk of OSA and both can be influenced by genetics. Structural risk factors include craniofacial bony restriction, changes in fat distribution, and the size of the upper airway muscles. Physiologic risk factors include airway collapsibility, loop gain, pharyngeal muscle responsiveness, and arousal threshold. The consequences of OSA include daytime sleepiness and exacerbation of many underlying diseases. OSA has been associated with cardiovascular diseases including hypertension, coronary heart disease, stroke, atrial fibrillation, and other cardiac arrhythmias; pulmonary hypertension; metabolic disorders such as type 2 diabetes, hypothyroidism, acromegaly, Cushing syndrome, and polycystic ovarian syndrome; mild cognitive impairment or dementia; and cancer. This review contains 4 figures, 1 table and 48 references. Key Words: cardiac consequences, craniofacial bony restriction, epidemiology, fat distribution, metabolic disease, neurodegeneration, obesity, obstructive sleep apnea

Predominant role of peripheral chemoreceptors in the termination of apnea in maturing newborn lambs

1996 ◽  
Vol 80 (3) ◽  
pp. 892-898 ◽  
Author(s):  
C. Delacourt ◽  
E. Canet ◽  
M. A. Bureau
Keyword(s):  
Carotid Body ◽  
Pco2 Level ◽  
Peripheral Chemoreceptor ◽  
Arterial Pco2 ◽  
Postnatal Maturation ◽  
Body Function ◽  
Life Threatening ◽  
Prolonged Apnea ◽  
Arterial Po2

Apneas are very common and normal in newborns but may become life threatening if they are not terminated appropriately. The aim of this study in newborn lambs was to investigate the influence on apnea termination of postnatal maturation, peripheral chemoreceptor function, and hypoxia. Apneas were induced by passive hyperventilation at varying inspired O2 fraction levels. The apnea termination threshold PCO2 (PATTCO2) was defined as the arterial PCO2 value at the first breath after the apnea. Three groups of awake intubated lambs were studied: 1) intact lambs tested at both 1 and 15 days of life, 2) intact 1-day-old lambs with central tissue hypoxia induced by CO inhalation, and 3) 1-day-old lambs with carotid body denervation (CBD). In individual lambs and regardless of age and carotid body function, there was a PO2-PCO2 response curve that was a determinant for the termination of an apnea. PATTCO2 invariably increased when arterial PO2 increased, regardless of age. During hypoxia and normoxia, PATTCO2 was significantly lower in 15-day-old lambs compared with 1-day-old lambs. No difference was seen during hyperoxia. PATTCO2 values were shifted to higher levels after carotid body removal. Finally, hypoxia induced by either a low inspired O2 fraction or CO inhalation consistently failed to induce a depressive effect on the PATTCO2 even in CBD lambs. In conclusion, in awake newborn lambs, the PCO2 level for apnea termination changed with postnatal age, and carotid body function was essential in lowering PATTCO2, thus protecting the lambs against prolonged apnea. Furthermore, hypoxia consistently failed to depress the reinitiation of breathing after apnea, even in CBD lambs.

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