HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Free Full Text (PDF) Free All Versions of this Article: 102/2/772    most recent 00683.2006v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (7) Citing Articles via Google Scholar Google Scholar Articles by Saboisky, J. P. Articles by Butler, J. E. Search for Related Content PubMed PubMed Citation Articles by Saboisky, J. P. Articles by Butler, J. E.

Differential activation among five human inspiratory motoneuron pools during tidal breathing

¹Prince of Wales Medical Research Institute and University of New South Wales, Sydney, Australia; and ²Laboratory of Cardiorespiratory Physiology, Chest Service, Erasme University Hospital, Brussels, Belgium

Submitted 19 June 2006 ; accepted in final form 11 October 2006

Neural drive to inspiratory pump muscles is increased under many pathological conditions. This study determined for the first time how neural drive is distributed to five different human inspiratory pump muscles during tidal breathing. The discharge of single motor units (n = 280) from five healthy subjects in the diaphragm, scalene, second parasternal intercostal, third dorsal external intercostal, and fifth dorsal external intercostal was recorded with needle electrodes. All units increased their discharge during inspiration, but 41 (15%) discharged tonically throughout expiration. Motor unit populations from each muscle differed in the timing of their activation and in the discharge rates of their motor units. Relative to the onset of inspiratory flow, the earliest recruited muscles were the diaphragm and third dorsal external intercostal (mean onset for the population after 26 and 29% of inspiratory time). The fifth dorsal external intercostal muscle was recruited later (43% of inspiratory time; P < 0.05). Compared with the other inspiratory muscles, units in the diaphragm and third dorsal external intercostal had the highest onset (7.7 and 7.1 Hz, respectively) and peak firing frequencies (12.6 and 11.9 Hz, respectively; both P < 0.05). There was a unimodal distribution of recruitment times of motor units in all muscles. Neural drive to human inspiratory pump muscles differs in timing, strength, and distribution, presumably to achieve efficient ventilation.

motor unit; respiratory control; inspiratory muscles; breathing; human

This article has been cited by other articles:

				M. Eikermann, S. Zaremba, A. Malhotra, A. S. Jordan, C. Rosow, and N. L. Chamberlin Neostigmine but not sugammadex impairs upper airway dilator muscle activity and breathing Br. J. Anaesth., June 16, 2008; (2008) aen176v1. [Abstract] [Full Text] [PDF]

				D. J. Eckert, R. D. McEvoy, K. E. George, K. J. Thomson, and P. G. Catcheside Effects of hypoxia on genioglossus and scalene reflex responses to brief pulses of negative upper-airway pressure during wakefulness and sleep in healthy men J Appl Physiol, May 1, 2008; 104(5): 1426 - 1435. [Abstract] [Full Text] [PDF]

				J. E. Butler and S. C. Gandevia The output from human inspiratory motoneurone pools J. Physiol., March 1, 2008; 586(5): 1257 - 1264. [Abstract] [Full Text] [PDF]

				A. L. Hudson, S. C. Gandevia, and J. E. Butler The effect of lung volume on the co-ordinated recruitment of scalene and sternomastoid muscles in humans J. Physiol., October 1, 2007; 584(1): 261 - 270. [Abstract] [Full Text] [PDF]