Control of nasal dilator muscle activities during exercise: Role of nasopharyngeal afferents

Jenna Sullivan, David Fuller, Ralph F. Fregosi

Research output: Contribution to journalArticlepeer-review

21 Scopus citations

Abstract

Our primary aim was to determine whether reducing the activity of nasal airway receptors would influence drive to the nasal dilator muscles (NDMs) during exercise. We used lidocaine (2%) or nasal splints to diminish afferent airway receptor activity and measured the electromyogram (EMG) activity of the NDMs during incremental bicycle exercise in subjects who breathed nasally. NDM EMG activities increased as a function of exercise intensity but were not changed by lidocaine and were only slightly reduced by splinting. Similarly, neither intervention altered the normal decrease in NDM EMG activity associated with reductions in airway resistance evoked by He-O2 breathing. We also compared the NDM EMG response to exercise with that evoked by CO2 rebreathing at rest to determine whether the nature of the ventilatory stimulus influences drive to the NDMs; comparisons were made at constant levels of nasal inspired ventilation and, therefore, constant total ventilatory output. The increase in EMG activity was much higher during exercise compared with hyperoxic hypercapnia. In conclusion, 1) desensitizing the nasal airway does not alter NDM activity significantly during exercise and 2) exercise results in much greater increases in NDM activity compared with hypercapnia, indicating that different ventilatory stimuli can evoke more or less activation of upper airway motoneurons, even when comparisons are made at constant levels of total ventilatory output.

Original languageEnglish (US)
Pages (from-to)1520-1527
Number of pages8
JournalJournal of Applied Physiology
Volume80
Issue number5
DOIs
StatePublished - May 1996

Keywords

  • carbon dioxide rebreathing
  • control of breathing
  • facial motoneurons
  • lidocaine
  • nasal splints

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

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