title: Remote control of respiratory neural network by spinal locomotor generators.
abstract: During exercise and locomotion, breathing rate rapidly increases to meet the suddenly enhanced oxygen demand. The extent to which direct central interactions between the spinal networks controlling locomotion and the brainstem networks controlling breathing are involved in this rhythm modulation remains unknown. Here, we show that in isolated neonatal rat brainstem-spinal cord preparations, the increase in respiratory rate observed during fictive locomotion is associated with an increase in the excitability of pre-inspiratory neurons of the parafacial respiratory group (pFRG/Pre-I). In addition, this locomotion-induced respiratory rhythm modulation is prevented both by bilateral lesion of the pFRG region and by blockade of neurokinin 1 receptors in the brainstem. Thus, our results assign pFRG/Pre-I neurons a new role as elements of a previously undescribed pathway involved in the functional interaction between respiratory and locomotor networks, an interaction that also involves a substance P-dependent modulating mechanism requiring the activation of neurokinin 1 receptors. This neurogenic mechanism may take an active part in the increased respiratory rhythmicity produced at the onset and during episodes of locomotion in mammals.
authors.affiliation: Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, CNRS, University of Bordeaux, Bordeaux, France.
authors.forename: Jean-Patrick
authors.initials: JP
authors.lastname: Le Gal
authors.affiliation: Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, CNRS, University of Bordeaux, Bordeaux, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Juvin
authors.affiliation: Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, CNRS, University of Bordeaux, Bordeaux, France.
authors.forename: Laura
authors.initials: L
authors.lastname: Cardoit
authors.affiliation: Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, CNRS, University of Bordeaux, Bordeaux, France.
authors.forename: Muriel
authors.initials: M
authors.lastname: Thoby-Brisson
authors.affiliation: Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, CNRS, University of Bordeaux, Bordeaux, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Morin
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001933:Brain Stem / Q000187:drug effects / Q000502:physiology*; D004558:Electric Stimulation; D008124:Locomotion / Q000502:physiology; D016202:N-Methylaspartate; D009415:Nerve Net / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D017207:Rats, Sprague-Dawley; D018040:Receptors, Neurokinin-1; D012119:Respiration; D012125:Respiratory Center / Q000502:physiology*; D012701:Serotonin / Q000494:pharmacology; D013116:Spinal Cord / Q000502:physiology*
chemical_list: D018040:Receptors, Neurokinin-1; D012701:Serotonin; D016202:N-Methylaspartate