Details

Autor(en) / Beteiligte

• Le Gal, Jean‐Patrick
• Colnot, Eloïse
• Cardoit, Laura
• Bacqué-Cazenave, Julien
• Thoby‐Brisson, Muriel
• Juvin, Laurent
• Morin, Didier

Titel

Modulation of respiratory network activity by forelimb and hindlimb locomotor generators

Ist Teil von

• The European journal of neuroscience, 2020-08, Vol.52 (4), p.3181-3195

Ort / Verlag

France: Wiley Subscription Services, Inc

Erscheinungsjahr

2020

Link zum Volltext

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• 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. Early at the onset of exercise, breathing rate accelerates to anticipate the increasing metabolic demand. Using isolated brainstem‐spinal cord preparations from neonatal rats and mice, we show here that lumbar spinal networks engaged in generating hindlimb locomotor rhythms are capable of activating the brainstem respiratory centres through an ascending excitatory drive and that cervicothoracic circuitry may also contribute to locomotion‐induced respiratory frequency increase.