scholarly journals Coordinated Respiratory Motor Activity in Nerves Innervating the Upper Airway Muscles in Rats

PLoS ONE ◽  
2016 ◽  
Vol 11 (11) ◽  
pp. e0166436 ◽  
Author(s):  
Satoshi Tachikawa ◽  
Kiyomi Nakayama ◽  
Shiro Nakamura ◽  
Ayako Mochizuki ◽  
Takehiko Iijima ◽  
...  
1998 ◽  
Vol 275 (4) ◽  
pp. R1013-R1024 ◽  
Author(s):  
Victor Fenik ◽  
Richard O. Davies ◽  
Allan I. Pack ◽  
Leszek Kubin

Microinjections of carbachol into the pontine tegmentum of decerebrate cats have been used to study the mechanisms underlying the suppression of postural and respiratory motoneuronal activity during the resulting rapid eye movement (REM) sleep-like atonia. During REM sleep, distinct respiratory muscles are differentially affected; e.g., the activity of the diaphragm shows little suppression, whereas the activity of some upper airway muscles is quite strong. To determine the pattern of the carbachol-induced changes in the activity of different groups of upper airway motoneurons, we simultaneously recorded the efferent activity of the recurrent laryngeal nerve (RL), pharyngeal branch of the vagus nerve (Phar), and genioglossal branch of the hypoglossal (XII) and phrenic (Phr) nerves in 12 decerebrate, paralyzed, vagotomized, and artificially ventilated cats. Pontine carbachol caused a stereotyped suppression of the spontaneous activity that was significantly larger in Phar expiratory (to 8.3% of control) and XII inspiratory motoneurons (to 15%) than in Phr inspiratory (to 87%), RL inspiratory (to 79%), or RL expiratory motoneurons (to 72%). The suppression in upper airway motor output was significantly greater than the depression caused by a level of hypocapnia that reduced Phr activity as much as carbachol. We conclude that pontine carbachol evokes a stereotyped pattern of suppression of upper airway motor activity. Because carbachol evokes a state having many neurophysiological characteristics similar to those of REM sleep, it is likely that pontine cholinoceptive neurons have similar effects on the activity of upper airway motoneurons during both states.


1985 ◽  
Vol 58 (5) ◽  
pp. 1489-1495 ◽  
Author(s):  
J. P. Farber

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.


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

2020 ◽  
Author(s):  
Diane C Lim ◽  
Richard J Schwab

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


1991 ◽  
Vol 53 (1) ◽  
pp. 93-99 ◽  
Author(s):  
Osamu KAMINUMA ◽  
Hirokazu TSUBONE ◽  
Job Manaet MATIAS ◽  
Ryohei NISHIMURA ◽  
Shigeru SUGANO

1990 ◽  
Vol 68 (3) ◽  
pp. 1041-1047 ◽  
Author(s):  
W. A. Carlo ◽  
J. M. DiFiore

Upper airway muscles and the diaphragm may have different quantitative responses to chemoreceptor stimulation. To compare the respiratory muscle responses to changes in CO2, 10 ventilator-dependent preterm infants (gestational age 28 +/- 1 wk, postnatal age 40 +/- 6 days, weight 1.4 +/- 0.1 kg) were passively hyperventilated to apnea and subsequently hypoventilated. Electromyograms from the genioglossus, alae nasi, posterior cricoarytenoid, and diaphragm were recorded from surface electrodes. Apneic CO2 thresholds of all upper airway muscles (genioglossus 46.8 +/- 4.3 Torr, alae nasi 42.4 +/- 3.6 Torr, posterior cricoarytenoid 41.6 +/- 3.2 Torr) were higher than those of the diaphragm (38.8 +/- 2.6 Torr, all P less than 0.05). Above their CO2 threshold levels, responses of all upper airway muscles appeared proportional to those of the diaphragm. We conclude that nonproportional responses of the respiratory muscles to hypercapnia may be the result of differences in their CO2 threshold. These differences in CO2 threshold may cause imbalance in respiratory muscle activation with changes in chemical drive, leading to upper airway instability and obstructive apnea.


2008 ◽  
Vol 105 (5) ◽  
pp. 1471-1476 ◽  
Author(s):  
Andrew D. Ray ◽  
Toshiyuki Ogasa ◽  
Ulysses J. Magalang ◽  
John A. Krasney ◽  
Gaspar A. Farkas

The upper airway muscles play an important role in maintaining upper airway collapsibility, and the incidence of sleep-disordered breathing increases with age. We hypothesize that the increase in airway collapsibility with increasing age can be linked to changes in upper airway muscle mechanics and structure. Eight young (Y: 6 mo) and eight old (O: 30 mo) Fischer 344 rats were anesthetized and mechanically ventilated, and the pharyngeal pressure associated with flow limitation (Pcrit) was measured 1) with the hypoglossal (cnXII) nerve intact, 2) following bilateral cnXII denervation, and 3) during cnXII stimulation. With the cnXII intact, the upper airways of older rats were more collapsible compared with their younger counterparts [Pcrit = −7.1 ± 0.6 (SE) vs. −9.5 ± 0.7 cmH2O, respectively; P = 0.033]. CnXII denervation resulted in an increase in Pcrit such that Pcrit became similar in both groups (O: −4.2 ± 0.5 cmH2O; Y: −5.4 ± 0.5 cmH2O). In all rats, cnXII stimulation decreased Pcrit (less collapsible) in both groups (O: −11.3 ± 1.0 cmH2O; Y: −10.2 ± 1.0 cmH2O). The myosin heavy chain composition of the genioglossus muscle demonstrated a decrease in the percentage of the IIb isoform (38.3 ± 2.5 vs. 21.7 ± 1.7%; P < 0.001); in contrast, the sternohyoid muscle demonstrated an increase in the percentage of the IIb isoform (72.2 ± 2.5 vs. 58.4 ± 2.3%; P = 0.001) with age. We conclude that the upper airway becomes more collapsible with age and that the increase in upper airway collapsibility with age is likely related to altered neural control rather than to primary alterations in upper airway muscle structure and function.


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)


1988 ◽  
Vol 72 (2) ◽  
pp. 163-170
Author(s):  
K.C. Lahive ◽  
J.W. Weiss ◽  
S.E. Weinberger
Keyword(s):  
Low Dose ◽  

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