Remote Control of Respiratory Neural Network by Spinal Locomotor Generators
PLoS ONE. 2014-02-20; 9(2): e89670
Read on PubMed
Le Gal JP(1), Juvin L(1), Cardoit L(1), Thoby-Brisson M(1), Morin D(1).
(1)Institut de Neurosciences Cognitives et Intégratives d’Aquitaine, CNRS,
University of Bordeaux, Bordeaux, France.
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.