Pontine influences on respiratory control in ectothermic and heterothermic vertebrates

• Published in: Respiratory physiology & neurobiology 2004-11, Vol.143 (2), p.263-280
• Main Authors: Milsom, William K., Chatburn, Jonathan, Zimmer, M. Beth
• Format: Article
• Language: English
• Subjects: Animals; Control of breathing, pontine mechanisms, rhythmogenesis; Development, ontogeny, phylogeny; Humans; Isthmus rhombencephali; Medulla, pons; Motor Neurons - physiology; Parafacial complex; Pattern of breathing; Periodicity; Phylogeny; Pons - anatomy & histology; Pons - physiology; Respiration; Respiratory Physiological Phenomena; Reticular Formation - anatomy & histology; Reticular Formation - physiology; Species Specificity; Vertebrates - physiology
• ISSN: 1569-9048; 1878-1519
• DOI: 10.1016/j.resp.2004.05.008

Respiratory rhythm generators appear both evolutionarily and developmentally as paired segmental rhythm generators in the reticular formation, associated with the motor nuclei of cranial nerves V, VII, IX, X, and XII. Those associated with the Vth and VIIth motor nuclei are “pontine” in origin and in fishes that employ a buccal suction/force pump for breathing the primary pair of respiratory rhythm generators are associated with the trigeminal nuclei. In amphibians, while the basic respiratory pump remains the same, the dominant site of respiratory rhythm generation has been assumed by the facial, glossopharyngeal and vagal motor nuclei. In reptiles, birds and mammals, in general there is a switch to an aspiration pump driven by thoraco-lumbar muscles innervated by spinal nerves. In these groups, the critical sites necessary for respiratory rhythmogenesis now sit near the ponto-medullary border, in the parafacial region (which may underlie expiratory-dominated, intercostal–abdominal breathing in non-mammalian tetrapods) and in a more caudal region, the preBötzinger complex (which may underlie inspiratory-dominated diaphragmatic breathing in mammals).