Abstract
Evolution of central respiratory chemosensitivity has been linked traditionally to the need for carbon dioxide regulation that accompanied the evolution of air breathing in terresterial animals. We examined the validity of this linkage by investigating the possibility of central chemoreception in air breathing fish that diverged from the amphibian lineage long before the appearance of terrestriality. We showed that the isolated brainstem preparation of the long nose gar ( Lepisosteus osseus) produces a putative motor pattern for lung ventilation, which is responsive to CO 2. These findings, together with more inferential evidence, suggest an association between air breathing and central chemosensitivity in aquatic animals that spans the major branches in vertebrate phylogeny. Furthermore, developmental observations in tadpoles suggest that the neural substrates for central chemoreception exist in proximity to that for rhythm generation. We postulate that a primitive ancestral CPG, sensitive to CO 2 is conserved and is evidenced in the intrinsic coupling of respiratory CPG and central chemoreception in modern tetrapods.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.