Effect of upper airway negative pressure on proprioceptive afferents from the tongue

1999 ◽  
Vol 86 (4) ◽  
pp. 1396-1401 ◽  
Author(s):  
A. Brancatisano ◽  
P. Davis ◽  
T. van der Touw ◽  
J. R. Wheatley
Keyword(s):  
Hypoglossal Nerve ◽  
Upper Airway ◽  
Rapid Onset ◽  
Firing Frequency ◽  
Tongue Muscle ◽  
Airway Mucosa ◽  
Afferent Fibers ◽  
Before And After ◽  
Proprioceptive Afferents ◽  
Passive Stretch

We examined whether receptors in the tongue muscle respond to negative upper airway pressure (NUAP). In six cats, one hypoglossal nerve was cut and its distal end was prepared for single-fiber recording. Twelve afferent fibers were selected for study on the basis of their sensitivity to passive stretch (PS) of the tongue. Fiber discharge frequency was measured during PS of the tongue and after the rapid onset of constant NUAP. During PS of 1–3 cm, firing frequency increased from 17 ± 7 to 40 ± 11 (SE) Hz ( P < 0.01). In addition, 8 of the 12 fibers responded to NUAP (−10 to −30 cmH2O), with firing frequency increasing from 23 ± 9 to 41 ± 9 Hz ( P < 0.001). In two fibers tested, the increase in firing frequency in response to NUAP was not altered by topical anesthesia (10% lignocaine) applied liberally to the entire upper airway mucosa. Our results demonstrate that afferent discharges from the hypoglossal nerve are elicited by 1) stretching of the tongue and 2) NUAP before and after upper airway anesthesia. We speculate that activation of proprioceptive mechanoreceptors in the cat’s tongue provides an additional pathway for the reflex activation of upper airway dilator muscles in response to NUAP, independent of superficially located mucosal mechanoreceptors.

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.

Chronic Estrogen Sensitizes a Subset of Mechanosensitive Afferents Innervating the Uterine Cervix

2005 ◽  
Vol 93 (4) ◽  
pp. 2167-2173 ◽  
Author(s):  
Baogang Liu ◽  
James C. Eisenach ◽  
Chuanyao Tong
Keyword(s):  
Spontaneous Activity ◽  
Uterine Cervix ◽  
Firing Frequency ◽  
High Threshold ◽  
Group 13 ◽  
Ovx Rats ◽  
Afferent Fibers ◽  
Low Threshold ◽  
Group 5 ◽  
Afferent Response

Estrogen increases reflex nocifensive responses to distension of the uterus and the urinary bladder, but estrogen's effects on afferent response to distension of the uterine cervix, the site of obstetric and some gynecologic pain, has not been studied. Here, single fiber recording of hypogastric nerve responses to uterine cervical distension were obtained from ovariectomized (OVX) rats and OVX rats treated with estrogen (ES). Spontaneous activity was greater in the ES group (13 of 24 units; 54%) than in the OVX group (6 of 27 units; 22%). ES differentially altered the response of low- and high-threshold units to distension. For high-threshold units, firing frequency was increased two- to fourfold with 60–100 gm distension in ES compared with OVX groups ( P < 0.05). In contrast, the response of low-threshold units to distension was not altered by ES. About one-half of units tested in each group responded to a temperature increase from 35 to 49°C. A greater proportion of thermosensitive units were also mechanosensitive in the ES group (7 of 8 afferents, 88%) than in the OVX group (5 of 11 afferents, 45%). Acute application of ES in OVX rats failed to evoke or increase distension-induced responses. These data show the polymodal nature of afferent fibers innervating the uterine cervix. Increased spontaneous activity with ES may play a part in remodeling of the cervical tissue, whereas selective sensitization of high-threshold units by ES might underlie increased pain responses to cervical distension. Failure of acute ES treatment to mimic this suggests a genomic effect.

Ventilatory dynamics during transient arousal from NREM sleep: implications for respiratory control stability

1996 ◽  
Vol 80 (5) ◽  
pp. 1475-1484 ◽  
Author(s):  
M. C. Khoo ◽  
S. S. Koh ◽  
J. J. Shin ◽  
P. R. Westbrook ◽  
R. B. Berry
Keyword(s):  
Respiratory Control ◽  
Upper Airway ◽  
Nrem Sleep ◽  
Before And After ◽  
Stage 2 Sleep ◽  
Repeated Administrations ◽  
Time Courses ◽  
Control Stability ◽  
Airway Dynamics ◽  
Normal Adults

The polysomnographic and ventilatory patterns of nine normal adults were measured during non-rapid-eye-movement (NREM) stage 2 sleep before and after repeated administrations of a tone (40-72 dB) lasting 5 s. The ventilatory response to arousal (VRA) was determined in data sections showing electrocortical arousal following the start of the tone. Mean inspiratory flow and tidal volume increased significantly above control levels in the first seven breaths after the start of arousal, with peak increases (64.2% > control) occurring on the second breath. Breath-to-breath occlusion pressure 100 ms after the start of inspiration showed significant increases only on the second and third postarousal breaths, whereas upper airway resistance declined immediately and remained below control for > or = 7 consecutive breaths. These results suggest that the first breath and latter portion of the VRA are determined more by upper airway dynamics than by changes in the neural drive to breathe. Computer model simulations comparing different VRA time courses show that sustained periodic apnea is more likely to occur when the fall in the postarousal increase in ventilation is more abrupt.

Computational Modeling of Upper Airway Before and After Adenotonsillectomy for Obstructive Sleep Apnea

2008 ◽  
Vol 118 (2) ◽  
pp. 360-362 ◽  
Author(s):  
Mihai Mihaescu ◽  
Shanmugam Murugappan ◽  
Ephraim Gutmark ◽  
Lane F. Donnelly ◽  
Maninder Kalra
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Computational Modeling ◽  
Upper Airway ◽  
Obstructive Sleep ◽  
Before And After

scholarly journals Characterization of epithelial cells, connective tissue cells and immune cells in human upper airway mucosa by immunofluorescence multichannel image cytometry: a pilot study

2020 ◽  
Author(s):  
Aris I. Giotakis ◽  
Jozsef Dudas ◽  
Rudolf Glueckert ◽  
Daniel Dejaco ◽  
Julia Ingruber ◽  
...  
Keyword(s):  
Connective Tissue ◽  
Chronic Rhinosinusitis ◽  
Immune Cells ◽  
Upper Airway ◽  
Image Cytometry ◽  
Cell Types ◽  
Epithelial Layer ◽  
Double Positive ◽  
Airway Mucosa ◽  
Single Positive

AbstractEpithelial, connective tissue and immune cells contribute in various ways to the pathophysiology of chronic rhinosinusitis (CRS). However, data of their distribution in upper airway mucosa are sparse. We aimed to provide quantitative, purely informative data on the distribution of these cell lineages and their coexpression patterns, which might help identifying, e.g., cells in the epithelium undergoing through epithelial–mesenchymal transition (EMT). For this purpose, we used immunofluorescence multichannel image cytometry (IMIC). We examined fixed paraffin-embedded tissue samples (FFPE) of six patients with chronic rhinosinusitis (CRS) and of three patients without CRS (controls). The direct-conjugated antibodies pancytokeratin, vimentin and CD45/CD18 were used for coexpression analysis in epithelial layer and lamina propria. Image acquisition and analysis were performed with TissueFAXS and StrataQuest, respectively. To distinguish positive from negative expression, a ratio between cell-specific immunostaining intensity and background was developed. Isotype controls were used as negative controls. Per patient, a 4.5-mm2 tissue area was scanned and a median of 14,875 cells was recognized. The most common cell types were cytokeratin-single-positive (26%), vimentin-single-positive (13%) and CD45/CD18-single-positive with CD45/CD18–vimentin-double-positive cells (29%). In the patients with CRS, CD45/CD18-single-positive cells were 3–6 times higher compared to the control patients. In the epithelial layer, cytokeratin–vimentin-double-positive EMT cells were observed 3–5 times higher in the patients with CRS than in the control patients. This study provided quantitative data for the distribution of crucial cell types in CRS. Future studies may focus on the distribution and coexpression patterns of different immune cells in CRS or even cancer tissue.

scholarly journals N-dihydrogalactochitosan reduces mortality in a lethal mouse model of SARS-CoV-2

2021 ◽  
Author(s):  
Christopher M Weiss ◽  
Hongwei Liu ◽  
Erin E Ball ◽  
Samuel Lam ◽  
Tomas Hode ◽  
...  
Keyword(s):  
Immune Responses ◽  
Infectious Virus ◽  
Severe Disease ◽  
Upper Airway ◽  
Innate Immune ◽  
Morbidity And Mortality ◽  
Vaccine Hesitancy ◽  
Innate Immune Responses ◽  
Before And After ◽  
Rapid Emergence

The rapid emergence and global dissemination of SARS-CoV-2 that causes COVID-19 continues to cause an unprecedented global health burden resulting in more than 4 million deaths in the 20 months since the virus was discovered. While multiple vaccine countermeasures have been approved for emergency use, additional treatments are still needed due to sluggish vaccine rollout and vaccine hesitancy. Immunoadjuvant compounds delivered intranasally can guide non-specific innate immune responses during the critical early stages of viral replication, reducing morbidity and mortality. N-dihydrogalactochitosan (GC) is a novel mucoadhesive immunostimulatory polymer of β-0-4-linked N-acetylglucosamine that is solubilized by the conjugation of galactose glycans. We tested GC as a potential countermeasure for COVID-19. GC administered intranasally before and after SARS-CoV-2 exposure diminished morbidity and mortality in humanized ACE2 receptor expressing mice by up to 75% and reduced infectious virus levels in the upper airway and lungs. Our findings demonstrate a new application for soluble immunoadjuvants like GC for preventing severe disease associated with SARS-CoV-2.

Reflexive Response of Neck Muscle to Sudden Perturbation after Prolonged Smartphone Use

2021 ◽  
Vol 65 (1) ◽  
pp. 1250-1253
Author(s):  
Eunjee Kim ◽  
Donghyun Song ◽  
Dasom Park ◽  
Hyorim Kim ◽  
Gwanseob Shin
Keyword(s):  
Cervical Spine ◽  
Muscle Activation ◽  
Neck Muscle ◽  
Spinal Stability ◽  
Delayed Onset ◽  
Activation Level ◽  
Before And After ◽  
Smartphone Use ◽  
Head Stability ◽  
Passive Stretch

Prolonged smartphone use induces passive stretch of neck tissues and muscle fatigue, affecting spinal stability and pain. It is necessary to evaluate the effect of smartphone use on the reflexive response to detect the changes in neck tissues and head stability. A laboratory experiment (n=10) was conducted to investigate the reflexive response of neck muscle to perturbation after 30 minutes of smartphone use. Neck extensor muscle activation and its activation timing to perturbation were investigated before and after smartphone use. Head angle and muscle activation level were collected during smartphone use. During smartphone use, muscle activation gradually increased. After smartphone use, neck muscles showed a higher activation level and significantly delayed onset to perturbation. Smartphone use changed the reflexive response of the neck muscle. Further study is needed to investigate the association between smartphone use and neuromuscular changes to the tissues of the cervical spine.

Respiratory motor nerve activities during spontaneous bladder contractions

1994 ◽  
Vol 77 (3) ◽  
pp. 1349-1354 ◽  
Author(s):  
M. J. Gdovin ◽  
S. L. Knuth ◽  
D. Bartlett
Keyword(s):  
Hypoglossal Nerve ◽  
Motor Nerve ◽  
Upper Airway ◽  
Respiratory Response ◽  
Airway Patency ◽  
Pelvic Nerves ◽  
Initial Decrease ◽  
Posterior Cricoarytenoid ◽  
Increased Activity ◽  
Nerve Discharge

We monitored spontaneous bladder contractions (SBCs) in decerebrate vagotomized paralyzed ventilated cats while recording respiratory motor nerve activities and intravesical pressure under isovolumetric conditions. Phrenic nerve discharge diminished during SBCs, as did the activities of the hypoglossal nerve, the nasolabial branch of the facial nerve, and inspiratory (posterior cricoarytenoid) and expiratory (thyroarytenoid) branches of the recurrent laryngeal nerve. Hypoglossal activity was most strikingly reduced during SBCs, disappearing completely in some animals. The triangularis sterni nerve exhibited an initial decrease, followed by an increase in activity during SBCs, whereas the cranial iliohypogastric nerve showed increased activity. The changes in nerve activities during SBCs could also be elicited by passive distension of the bladder and were abolished by bilateral section of the pelvic nerves. These findings extend the understanding of reflexes originating from the urinary bladder to include a coordinated respiratory response and suggest that these reflexes may compromise upper airway patency under some conditions.

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