QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online April 18, 2006
Journal of Experimental Biology 209, 1709-1715 (2006)
Published by The Company of Biologists 2006
doi: 10.1242/jeb.02199

This Article Summary Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Florindo, L. H. Articles by Rantin, F. T. Search for Related Content PubMed PubMed Citation Articles by Florindo, L. H. Articles by Rantin, F. T.

The role of branchial and orobranchial O₂ chemoreceptors in the control of aquatic surface respiration in the neotropical fish tambaqui (Colossoma macropomum): progressive responses to prolonged hypoxia

Luiz H. Florindo¹, Cléo A. C. Leite², Ana L. Kalinin², Stephen G. Reid³, William K. Milsom⁴ and F. Tadeu Rantin^2,*

¹ Department of Zoology and Botany, São Paulo State University–UNESP, São José do Rio Preto, SP, Brazil
² Department of Physiological Sciences, Federal University of São Carlos, 13565-905 São Carlos, SP, Brazil
³ Division of Life Sciences, University of Toronto at Scarborough, Scarborough, OT, Canada
⁴ Department of Zoology, University of British Columbia, Vancouver, BC, Canada

View larger version (13K): [in a new window]   Fig. 1. Ventilation rate (fR) of tambaqui, Colossoma macropomum, exposed to normoxia (PwO2=140 mmHg at time zero) and then hypoxia (PwO2=10 mmHg) for 360 min. Intact (circles; N=10) and denervated fish (squares): (A) cranial nerves IX+X denervated (N=10), (B) cranial nerve V denervated (N=10) and (C) cranial nerves V+VII denervated (N=10). Values are mean ± s.e.m. Open symbols indicate values that are significantly (P<0.05) different from time zero. +Intact and denervated fish are significantly different.

View larger version (15K): [in a new window]   Fig. 2. Ventilation amplitude (VAMP) of tambaqui, Colossoma macropomum, exposed to normoxia (PwO2=140 mmHg at time zero) and then hypoxia (PwO2=10 mmHg) for 360 min. Intact (circles; N=10) and denervated fish (squares): (A) cranial nerves IX+X denervated (N=10), (B) cranial nerve V denervated (N=10) and (C) cranial nerves V+VII denervated (N=10). Values are mean ± s.e.m. Open symbols indicate values that are significantly (P<0.05) different from time zero. +Intact and denervated fish are significantly different.

View larger version (12K): [in a new window]   Fig. 3. Heart rate (fH) of tambaqui, Colossoma macropomum, exposed to normoxia (PwO2=140 mmHg at time zero) and then hypoxia (PwO2=10 mmHg) for 360 min. Intact (circles; N=10) and denervated fish (squares): (A) cranial nerves IX+X denervated (N=10), (B) cranial nerve V denervated (N=10) and (C) cranial nerves V+VII denervated (N=10). Values are mean ± s.e.m. Open symbols indicate values that are significantly (P<0.05) different from time zero. +Intact and denervated fish are significantly different.

View larger version (18K): [in a new window]   Fig. 4. (A) ASR frequency and (B) time spent in ASR (time spent at the surface) of tambaqui, Colossoma macropomum, exposed to normoxia (PwO2=140 mmHg at time zero) and then severe hypoxia (PwO2=10 mmHg) for 360 min. Circles, intact fish (N=8); squares, fish with cranial nerves IX+X denervated (N=8); triangles, fish with cranial nerve V denervated (N=8). Values are means ± s.e.m. Open symbols indicate values that are significantly (P<0.05) different from time zero. +Intact and denervated fish are significantly different.

View larger version (18K): [in a new window]   Fig. 5. Area of lower lip of tambaqui, Colossoma macropomum, exposed to normoxia and then 360 min of severe hypoxia (PwO2=10 mmHg). (A) Open bars, intact fish (N=8); filled bars, fish with cranial nerves IX+X denervated (N=8). (B) Open bars, intact fish (N=8); filled bars, fish with cranial nerve V denervated (N=8); grey bars, fish with cranial nerves V+VII denervated (N=8). N, normoxia; H, hypoxia; Values are means ± s.e.m. *Values are significantly (P<0.05) different from the normoxic values.