Comparative aspects of central CO2 chemoreception.

Abstract

We compare and contrast the putative mechanisms underlying CO2 chemoreceptor function in air breathing vertebrates and terrestrial pulmonate snails. We discuss the role of intracellular pH (pHi) in central respiratory responses to CO2 and describe a variety of patterns of pHi regulation in chemosensory areas. One pattern, in which pHi retains a fixed relationship to the CO2 stimulus over time, seems well suited to chemoreceptor cells. Alphastat regulation of ventilation is apparent in both air breathing vertebrates and terrestrial pulmonate snails. Diethyl pyrocarbonate inhibits respiratory responses to hypercapnia in both groups of animals. The neuronal basis of chemosensitivity is similar, in that putative chemoreceptor cells depolarize during hypercapnic stimulation, but the ionic basis of excitability appears to be a potassium conductance in the vertebrates studied to date and a calcium conductance in the snails. Despite divergent evolutionary histories, chemosensory responses and mechanisms are remarkably similar in air breathing vertebrates and terrestrial pulmonate snails.

• Authors: J S Erlichman, J C Leiter
• Journal: Respiration physiology (Respir Physiol) Vol. 110 Issue 2-3 Pg. 177-85 (Nov 1997) ISSN: 0034-5687 [Print] Netherlands
• PMID: 9407610 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S., Review)

Chemical References

• Carbon Dioxide

Topics

• Animals
• Carbon Dioxide (blood, metabolism)
• Chemoreceptor Cells (physiology)
• Humans
• Respiratory Mechanics (physiology)