Neural regulation of discontinuous gas exchange in Periplaneta americana
Date
2008
Authors
Woodman, James
Cooper, Paul
Haritos, Victoria S
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
Patterns of gas exchange among terrestrial arthropods are highly variable from continuous to discontinuous with discretely partitioned phases. The underlying initiation and co-ordination of these patterns is relatively poorly understood. Here we present a novel method for the simultaneous measurement of central nervous system (CNS) activity of the metathoracic ganglion and VCO2 in medium to large sized live terrestrial arthropods. Using Periplaneta americana at four oxygen levels (40%, 21%, 10% and 2% at 25 °C; n=6 per treatment), we present minimally invasive visualization of nervous output relative to typical resting discontinuous gas exchange (DGE) data for the first time. DGE was maintained when cockroaches were exposed to hyperoxia or moderate hypoxia, but was lost in severe hypoxia. CNS activity was manifested in three signal types: large CNS output coinciding with peak CO2 production during a burst, moderate CNS output coinciding with CO2 sawtoothing and fluttering, and minimal CNS activity during the closed phase of DGE in normoxia. Large and moderate CNS outputs were associated with observed abdominal pumping and congruent CO2 peaks. At 10% oxygen, VCO2 was significantly elevated during the inter-burst period in association with almost constant moderate CNS output between the periodic large CNS output. At 2% oxygen, DGE and large CNS output are lost to continuous CO2 release and largely continuous moderate CNS output. As previously reported for this species, a central pattern generator for ventilation in the metathoracic ganglion is supported and we infer the presence of localized oxygen chemoreceptors based on clear CNS response to a change in oxygen tension.
Description
Keywords
Keywords: oxygen; cockroach; gas exchange; measurement method; nervous system; respiration; animal; article; central nervous system; lung gas exchange; Periplaneta; physiology; respiratory function; Animals; Central Nervous System; Oxygen; Periplaneta; Pulmonary Ga CNS; Discontinuous gas exchange; Metathoracic ganglion; Oxygen tension; Respirometry
Citation
Collections
Source
Journal of Insect Physiology
Type
Journal article
Book Title
Entity type
Access Statement
License Rights
Restricted until
2037-12-31
Downloads
File
Description