Remote control of respiratory neural network by spinal locomotor generators

PLoS One. 2014 Feb 20;9(2):e89670. doi: 10.1371/journal.pone.0089670. eCollection 2014.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Newborn
  • Brain Stem / drug effects
  • Brain Stem / physiology*
  • Electric Stimulation
  • Locomotion / physiology
  • N-Methylaspartate
  • Nerve Net / drug effects
  • Nerve Net / physiology*
  • Neurons / physiology
  • Rats, Sprague-Dawley
  • Receptors, Neurokinin-1
  • Respiration*
  • Respiratory Center / physiology*
  • Serotonin / pharmacology
  • Spinal Cord / physiology*

Substances

  • Receptors, Neurokinin-1
  • Serotonin
  • N-Methylaspartate

Grant support

This work was supported by grants from the Conseil Régional d'Aquitaine. JPLG was supported by doctoral grant from the French Ministère de l'Enseignement Supérieur et de la Recherche. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.