PO2 of the metathoracic ganglion in response to progressive hypoxia in an insect: PO2 of the insect central nervous system

Jon F. Harrison, Wolfgang Waser, Stefan K. Hetz

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

Mammals regulate their brain tissue PO2 tightly, and only small changes in brain PO2 are required to elicit compensatory ventilation. However, unlike the flow-through cardiovascular system of vertebrates, insect tissues exchange gases through blind-ended tracheoles, which may involve a more prominent role for diffusive gas exchange. We tested the effect of progressive hypoxia on ventilation and the PO2 of the metathoracic ganglion (neural site of control of ventilation) using microelectrodes in the American locust, Schistocerca americana. In normal air (21 kPa), PO2 of the metathoracic ganglion was 12 kPa. The PO2 of the ganglion dropped as air PO2 dropped, with ventilatory responses occurring when ganglion PO2 reached 3 kPa. Unlike vertebrates, insects tolerate relatively high resting tissue PO2 levels and allow tissue PO2 to drop during hypoxia, activity and discontinuous gas exchange before activating convective or spiracular gas exchange. Tracheated animals, and possibly pancrustaceans in general, seem likely to generally experience wide spatial and temporal variation in tissue PO2 compared with vertebrates, with important implications for physiological function and the evolution of oxygen-using proteins.

Original languageEnglish (US)
Article number20200548
JournalBiology letters
Volume16
Issue number11
DOIs
StatePublished - Nov 2020

Keywords

  • hypoxia
  • oxygen
  • tracheal system
  • ventilation

ASJC Scopus subject areas

  • Agricultural and Biological Sciences (miscellaneous)
  • Agricultural and Biological Sciences(all)

Fingerprint Dive into the research topics of 'PO2 of the metathoracic ganglion in response to progressive hypoxia in an insect: PO2 of the insect central nervous system'. Together they form a unique fingerprint.

Cite this