Discharge patterns of human tensor palatini motor units during sleep onset

Christian L. Nicholas, Amy S. Jordan, Leila Heckel, Christopher Worsnop, Bei Bei, Julian P. Saboisky, Danny J. Eckert, David P. White, Atul Malhotra, John A. Trinder

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Study Objectives: Upper airway muscles such as genioglossus (GG) and tensor palatini (TP) reduce activity at sleep onset. In GG reduced muscle activity is primarily due to inspiratory modulated motor units becoming silent, suggesting reduced respiratory pattern generator (RPG) output. However, unlike GG, TP shows minimal respiratory modulation and presumably has few inspiratory modulated motor units and minimal input from the RPG. Thus, we investigated the mechanism by which TP reduces activity at sleep onset.

Design: The activity of TP motor units were studied during relaxed wakefulness and over the transition from wakefulness to sleep.

Setting: Sleep laboratory.

Participants: Nine young (21.4 ± 3.4 years) males were studied on a total of 11 nights.

Intervention: Sleep onset.

Measurements and Results: Two TP EMGs (thin, hooked wire electrodes), and sleep and respiratory measures were recorded. One hundred twenty-one sleep onsets were identified (13.4 ± 7.2/subject), resulting in 128 motor units (14.3 ± 13.0/subject); 29% of units were tonic, 43% inspiratory modulated (inspiratory phasic 18%, inspiratory tonic 25%), and 28% expiratory modulated (expiratory phasic 21%, expiratory tonic 7%). There was a reduction in both expiratory and inspiratory modulated units, but not tonic units, at sleep onset. Reduced TP activity was almost entirely due to de-recruitment. Conclusions: TP showed a similar distribution of motor units as other airway muscles. However, a greater proportion of expiratory modulated motor units were active in TP and these expiratory units, along with inspiratory units, tended to become silent over sleep onset. The data suggest that both expiratory and inspiratory drive components from the RPG are reduced at sleep onset in TP.

Original languageEnglish
Pages (from-to)699-707
Number of pages9
JournalSLEEP
Volume35
Issue number5
DOIs
Publication statusPublished - 1 May 2012
Externally publishedYes

Keywords

  • sleep
  • upper airway muscles
  • obstructive sleep apnea

Fingerprint Dive into the research topics of 'Discharge patterns of human tensor palatini motor units during sleep onset'. Together they form a unique fingerprint.

  • Cite this

    Nicholas, C. L., Jordan, A. S., Heckel, L., Worsnop, C., Bei, B., Saboisky, J. P., Eckert, D. J., White, D. P., Malhotra, A., & Trinder, J. A. (2012). Discharge patterns of human tensor palatini motor units during sleep onset. SLEEP, 35(5), 699-707. https://doi.org/10.5665/sleep.1834