Po2-dependent changes in intrinsic and extrinsic tongue muscle activities in the rat

Elizabeth F Bailey, Patrick L. Janssen, Ralph F Fregosi

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

Rationale: Historically, respiratory-related research in sleep apnea has focused exclusively on the extrinsic tongue muscles (i.e., genioglossus, hyoglossus, and styloglossus). Until recently, the respiratory control and function of intrinsic tongue muscles (i.e., inferior and superior longitudinals, transverses, and verticalis), which comprise the bulk of the tongue, were unknown. Objectives: The current study sought to determine if extrinsic and intrinsic tongue muscles are coactivated in conditions of hypoxemia comparable to that experienced by adults with obstructive sleep apnea. Measurements: Esophageal pressure and EMG activity of an extrinsic (hyoglossus) and an intrinsic (superior longitudinal) tongue muscle were studied in anesthetized, tracheotomized, spontaneously breathing rats. Average EMG activity was compared in a control gas condition (Pao2, 160 ± 12 mm Hg) and in mild isocapnic hypoxia (Pao2, 69 ± 7.2 mm Hg), with and without brief (3-breath) airway occlusions, pre- and postbilateral vagotomy. Main Results: (1) intrinsic and extrinsic tongue muscles are coactivated in mild hypoxia, (2) airway occlusion increased the activities of intrinsic retractor muscles in mild hypoxia, and (3) extrinsic retractor muscles have a steeper rate of rise of activity and an earlier burst onset relative to intrinsic retractor activities in mild hypoxia. Conclusions: These findings support our working hypothesis that airway patency is maintained not simply by activation of extrinsic tongue muscles but by the coactivation of intrinsic and extrinsic protrudor and retractor muscles.

Original languageEnglish (US)
Pages (from-to)1403-1407
Number of pages5
JournalAmerican Journal of Respiratory and Critical Care Medicine
Volume171
Issue number12
DOIs
StatePublished - Jun 15 2005

Fingerprint

Tongue
Muscles
Vagotomy
Sleep Apnea Syndromes
Obstructive Sleep Apnea
Respiration
Gases
Hypoxia
Pressure
Research

Keywords

  • EMG
  • Hypoxia
  • Sleep apnea

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine

Cite this

Po2-dependent changes in intrinsic and extrinsic tongue muscle activities in the rat. / Bailey, Elizabeth F; Janssen, Patrick L.; Fregosi, Ralph F.

In: American Journal of Respiratory and Critical Care Medicine, Vol. 171, No. 12, 15.06.2005, p. 1403-1407.

Research output: Contribution to journalArticle

@article{62f93840459848b4af44ea22fd283f46,
title = "Po2-dependent changes in intrinsic and extrinsic tongue muscle activities in the rat",
abstract = "Rationale: Historically, respiratory-related research in sleep apnea has focused exclusively on the extrinsic tongue muscles (i.e., genioglossus, hyoglossus, and styloglossus). Until recently, the respiratory control and function of intrinsic tongue muscles (i.e., inferior and superior longitudinals, transverses, and verticalis), which comprise the bulk of the tongue, were unknown. Objectives: The current study sought to determine if extrinsic and intrinsic tongue muscles are coactivated in conditions of hypoxemia comparable to that experienced by adults with obstructive sleep apnea. Measurements: Esophageal pressure and EMG activity of an extrinsic (hyoglossus) and an intrinsic (superior longitudinal) tongue muscle were studied in anesthetized, tracheotomized, spontaneously breathing rats. Average EMG activity was compared in a control gas condition (Pao2, 160 ± 12 mm Hg) and in mild isocapnic hypoxia (Pao2, 69 ± 7.2 mm Hg), with and without brief (3-breath) airway occlusions, pre- and postbilateral vagotomy. Main Results: (1) intrinsic and extrinsic tongue muscles are coactivated in mild hypoxia, (2) airway occlusion increased the activities of intrinsic retractor muscles in mild hypoxia, and (3) extrinsic retractor muscles have a steeper rate of rise of activity and an earlier burst onset relative to intrinsic retractor activities in mild hypoxia. Conclusions: These findings support our working hypothesis that airway patency is maintained not simply by activation of extrinsic tongue muscles but by the coactivation of intrinsic and extrinsic protrudor and retractor muscles.",
keywords = "EMG, Hypoxia, Sleep apnea",
author = "Bailey, {Elizabeth F} and Janssen, {Patrick L.} and Fregosi, {Ralph F}",
year = "2005",
month = "6",
day = "15",
doi = "10.1164/rccm.200411-1550OC",
language = "English (US)",
volume = "171",
pages = "1403--1407",
journal = "American Journal of Respiratory and Critical Care Medicine",
issn = "1073-449X",
publisher = "American Thoracic Society",
number = "12",

}

TY - JOUR

T1 - Po2-dependent changes in intrinsic and extrinsic tongue muscle activities in the rat

AU - Bailey, Elizabeth F

AU - Janssen, Patrick L.

AU - Fregosi, Ralph F

PY - 2005/6/15

Y1 - 2005/6/15

N2 - Rationale: Historically, respiratory-related research in sleep apnea has focused exclusively on the extrinsic tongue muscles (i.e., genioglossus, hyoglossus, and styloglossus). Until recently, the respiratory control and function of intrinsic tongue muscles (i.e., inferior and superior longitudinals, transverses, and verticalis), which comprise the bulk of the tongue, were unknown. Objectives: The current study sought to determine if extrinsic and intrinsic tongue muscles are coactivated in conditions of hypoxemia comparable to that experienced by adults with obstructive sleep apnea. Measurements: Esophageal pressure and EMG activity of an extrinsic (hyoglossus) and an intrinsic (superior longitudinal) tongue muscle were studied in anesthetized, tracheotomized, spontaneously breathing rats. Average EMG activity was compared in a control gas condition (Pao2, 160 ± 12 mm Hg) and in mild isocapnic hypoxia (Pao2, 69 ± 7.2 mm Hg), with and without brief (3-breath) airway occlusions, pre- and postbilateral vagotomy. Main Results: (1) intrinsic and extrinsic tongue muscles are coactivated in mild hypoxia, (2) airway occlusion increased the activities of intrinsic retractor muscles in mild hypoxia, and (3) extrinsic retractor muscles have a steeper rate of rise of activity and an earlier burst onset relative to intrinsic retractor activities in mild hypoxia. Conclusions: These findings support our working hypothesis that airway patency is maintained not simply by activation of extrinsic tongue muscles but by the coactivation of intrinsic and extrinsic protrudor and retractor muscles.

AB - Rationale: Historically, respiratory-related research in sleep apnea has focused exclusively on the extrinsic tongue muscles (i.e., genioglossus, hyoglossus, and styloglossus). Until recently, the respiratory control and function of intrinsic tongue muscles (i.e., inferior and superior longitudinals, transverses, and verticalis), which comprise the bulk of the tongue, were unknown. Objectives: The current study sought to determine if extrinsic and intrinsic tongue muscles are coactivated in conditions of hypoxemia comparable to that experienced by adults with obstructive sleep apnea. Measurements: Esophageal pressure and EMG activity of an extrinsic (hyoglossus) and an intrinsic (superior longitudinal) tongue muscle were studied in anesthetized, tracheotomized, spontaneously breathing rats. Average EMG activity was compared in a control gas condition (Pao2, 160 ± 12 mm Hg) and in mild isocapnic hypoxia (Pao2, 69 ± 7.2 mm Hg), with and without brief (3-breath) airway occlusions, pre- and postbilateral vagotomy. Main Results: (1) intrinsic and extrinsic tongue muscles are coactivated in mild hypoxia, (2) airway occlusion increased the activities of intrinsic retractor muscles in mild hypoxia, and (3) extrinsic retractor muscles have a steeper rate of rise of activity and an earlier burst onset relative to intrinsic retractor activities in mild hypoxia. Conclusions: These findings support our working hypothesis that airway patency is maintained not simply by activation of extrinsic tongue muscles but by the coactivation of intrinsic and extrinsic protrudor and retractor muscles.

KW - EMG

KW - Hypoxia

KW - Sleep apnea

UR - http://www.scopus.com/inward/record.url?scp=20444391317&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=20444391317&partnerID=8YFLogxK

U2 - 10.1164/rccm.200411-1550OC

DO - 10.1164/rccm.200411-1550OC

M3 - Article

C2 - 15778485

AN - SCOPUS:20444391317

VL - 171

SP - 1403

EP - 1407

JO - American Journal of Respiratory and Critical Care Medicine

JF - American Journal of Respiratory and Critical Care Medicine

SN - 1073-449X

IS - 12

ER -