Perinatal development of respiratory motoneurons.
Breathing movements require the coordinated recruitment of cranial and spinal motoneurons innervating muscles of the upper airway and ribcage. A significant part of respiratory motoneuron development and maturation occurs prenatally to support the generation of fetal breathing movements in utero and sustained breathing at birth. Postnatally, motoneuron properties are further refined and match changes in the maturing respiratory musculoskeletal system. In this review, we outline developmental changes in key respiratory motoneuronal populations occurring from the time of motoneuron birth in the embryo through the postnatal period. We will also bring attention to major deficiencies in the current knowledge of perinatal respiratory motoneuron development. To date, our understanding of processes occurring during the prenatal period comes primarily from analysis of phrenic motoneurons (PMNs), whereas information about postnatal development derives largely from studies of PMN and hypoglossal motoneuron properties.
Greer
John J
JJ
Department of Physiology, Division of Neuroscience, 513 HMRC, Perinatal Research Centre, University of Alberta, Edmonton, Alta., Canada T6G 2S2. John.Greer@ualberta.ca
Funk
Gregory D
GD
D000818:Animals; D003964:Diaphragm / Q000294:innervation; D006801:Humans; D007002:Hypoglossal Nerve / Q000502:physiology; D009046:Motor Neurons / Q000502:physiology*; D012143:Respiratory Physiological Phenomena; D012137:Respiratory System / Q000196:embryology* / Q000294:innervation*; D014059:Tongue / Q000294:innervation