Journal
EUROPEAN JOURNAL OF NEUROSCIENCE
Volume 52, Issue 4, Pages 3181-3195Publisher
WILEY
DOI: 10.1111/ejn.14717
Keywords
locomotion; lumbar glutamatergic neurons; neonatal rodent; neural network interactions; respiration
Categories
Funding
- Fond de Recherche en Sante Respiratoire/Fondation du Souffle
- Ministere de l'Enseignement Superieur et de la Recherche Scientifique
Ask authors/readers for more resources
Early at the onset of exercise, breathing rate accelerates in order to anticipate the increasing metabolic demand resulting from the extra effort produced. Accordingly, the respiratory neural networks are the target of various input signals originating either centrally or peripherally. For example, during locomotion, the activation of muscle sensory afferents is able to entrain and thereby increase the frequency of spontaneous respiratory rhythmogenesis. Moreover, the lumbar spinal networks engaged in generating hindlimb locomotor rhythms are also capable of activating the medullary respiratory generators through an ascending excitatory command. However, in the context of quadrupedal locomotion, the influence of other spinal cord regions, such as cervical and thoracic segments, remains unknown. Using isolated brainstem-spinal cord preparations from neonatal rats and mice, we show that cervicothoracic circuitry may also contribute to locomotion-induced acceleration of respiratory cycle frequency. As previously observed for the hindlimb CPGs, the pharmacological activation of forelimb locomotor networks produces episodes of fictive locomotion that in turn increase the ongoing respiratory rhythm. Thoracic neuronal circuitry may also participate indirectly in this modulation via the activation of both cervical and lumbar CPG neurons. Furthermore, using light stimulation of CHR2-expressing glutamatergic neurons, we found that the modulation of the respiratory rate during locomotion involves lumbar glutamatergic circuitry. Our results demonstrate that during locomotion, the respiratory rhythm-generating networks receive excitatory ascending inputs from the spinal circuits responsible for generating and coordinating fore- and hindlimb movements. This constitutes a distributed central mechanism that contributes to matching breathing rate to the speed of locomotion.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available