title: Expiratory load compensation is associated with electroencephalographic premotor potentials in humans.
abstract: In normal humans during quiet breathing, expiration is mostly driven by elastic recoil of the lungs. Expiration becomes active when ventilation must be increased to meet augmented metabolic demands, or in response to expiratory loading, be it experimental or disease-related. The response to expiratory loading is considered to be mediated by both reflex and cortical mechanisms, but the latter phenomenon have not been neurophysiologically characterized. We recorded the EEG in 20 healthy volunteers (9 men, 11 women, age: 22 to 50 yr) during unloaded breathing, voluntary expirations, and in response to 50 cmH2O·l(-1)·s expiratory resistive load (ERL), 20 cmH2O expiratory threshold load (high ETL), and 10 cmH2O expiratory threshold load (low ETL). EEGs were processed by ensemble averaging expiratory time-locked segments and examined for pre-expiratory potentials, defined as a slow negative shift from the baseline signal preceding expiration, and suggestive of cortical preparation of expiration involving the supplementary motor area. Four subjects were excluded because of technical EEG problems. Pre-expiratory potentials were present in one subject at baseline and in all subjects during voluntary expirations. They were present in eight subjects during low ETL, in 15 subjects during high ETL, and in 13 subjets during ERL (control vs. low ETL, P = 0.008; control vs. high ETL, P < 0.001; and control vs. ERL, P < 0.001). Respiratory discomfort was more intense in the presence of pre-expiratory potentials (P < 0.001). These results provide a neurophysiological substrate to a cortical component of the physiological response to experimental expiratory loads in humans.
authors: Sorbonne Universités, Pierre and Marie Curie University, Univ Paris 06, UMRS 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France; Institut National de la Santé et de la Recherche Médicale, UMRS 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France; Assistance Publique-Hópitaux de Paris (AP-HP), Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département R3S), Paris, France;
authors: Elise
authors: E
authors: Morawiec
authors: Sorbonne Universités, Pierre and Marie Curie University, Univ Paris 06, UMRS 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France; Institut National de la Santé et de la Recherche Médicale, UMRS 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France; AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Département d'Anesthésie-Réanimation, Paris, France; and Centre de recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Canada.
authors: Mathieu
authors: M
authors: Raux
authors: Sorbonne Universités, Pierre and Marie Curie University, Univ Paris 06, UMRS 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France; Institut National de la Santé et de la Recherche Médicale, UMRS 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France; AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Département d'Anesthésie-Réanimation, Paris, France; and Centre de recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Canada.
authors: Felix
authors: F
authors: Kindler
authors: Sorbonne Universités, Pierre and Marie Curie University, Univ Paris 06, UMRS 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France; Institut National de la Santé et de la Recherche Médicale, UMRS 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France;
authors: Louis
authors: L
authors: Laviolette
authors: Sorbonne Universités, Pierre and Marie Curie University, Univ Paris 06, UMRS 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France; Institut National de la Santé et de la Recherche Médicale, UMRS 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France; Assistance Publique-Hópitaux de Paris (AP-HP), Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département R3S), Paris, France; thomas.similowski@psl.aphp.fr.
authors: Thomas
authors: T
authors: Similowski
mesh_terms: D000328:Adult; D004569:Electroencephalography; D045853:Exhalation; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008564:Membrane Potentials; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology*; D011897:Random Allocation; D055815:Young Adult
keywords: cerebral cortex; control of breathing; dyspnea; expiration; expiratory loading; supplementary motor area