title: Responses of the diaphragm to transcranial magnetic stimulation during wake and sleep in humans.
abstract: The human ventilation depends on bulbospinal and corticospinal commands. This study assessed their interactions in five healthy volunteers (two men, age 25-35) through the description of diaphragm and abductor pollicis brevis (APB) motor potentials (DiMEPs, abpMEPs) evoked by transcranial magnetic stimulation (TMS) during relaxed expiration and tidal inspiration and during wake and sleep. NREM decreased corticospinal excitability and REM further did so, for both the diaphragm and the APB. During wake, inspiration shortened supine DiMEPs latencies (expiration 18.56+/-1.90ms; inspiration 17.37+/-1.48ms, P<0.001). This persisted during sleep in an augmented manner (expiration: 21.05+/-1.39ms; inspiration 18.69+/-1.17ms, P=0.002). Inspiration had no effect on apbMEPs during wake and sleep.
  
  
  CONCLUSIONS
  (1) the tidal bulbospinal input to phrenic motoneurones is sufficient to modulate the throughput of the corticospinal pathway to these neurones; (2) this modulation is best seen after the sleep related removal of corticospinal and/or afferent inputs.
authors.affiliation: Laboratoire de Physiopathologie Respiratoire, Service de Pneumologie, Groupe Hospitalier Pitié Salpétrière, Assistance Publique-Hôpitaux de Paris, Paris, France.
authors.forename: Selma
authors.initials: S
authors.lastname: Mehiri
authors.forename: Christian
authors.initials: C
authors.lastname: Straus
authors.forename: Isabelle
authors.initials: I
authors.lastname: Arnulf
authors.forename: Valérie
authors.initials: V
authors.lastname: Attali
authors.forename: Marc
authors.initials: M
authors.lastname: Zelter
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Derenne
authors.forename: Thomas
authors.initials: T
authors.lastname: Similowski
mesh_terms: D000328:Adult; D003964:Diaphragm / Q000502:physiology*; D019054:Evoked Potentials, Motor; D045853:Exhalation / Q000502:physiology; D005260:Female; D006801:Humans; D001239:Inhalation / Q000502:physiology; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D011712:Pyramidal Tracts / Q000502:physiology; D011930:Reaction Time; D012890:Sleep / Q000502:physiology*; D012894:Sleep Stages / Q000502:physiology; D013933:Thumb; D050781:Transcranial Magnetic Stimulation; D014851:Wakefulness / Q000502:physiology*