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

This Article Full Text (PDF) References 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 Nilsson, G. Search for Related Content PubMed PubMed Citation Articles by Nilsson, G.

Journal of Experimental Biology, Vol 199, Issue 3 603-607, Copyright © 1996 by Company of Biologists

JOURNAL ARTICLES

Brain and body oxygen requirements of Gnathonemus petersii, a fish with an exceptionally large brain

G Nilsson

Vertebrates have repeatedly been noted for having remarkably constant ratios of brain to body O2 consumption, the brain using 2-8 % of resting body O2 consumption, suggesting that evolution has put strict limits on the energetic cost of brain function. Only man, with a value of 20 %, is an exception to this rule. However, the results presented here suggest that, in the electric fish Gnathonemus petersii, the brain is responsible for approximately 60 % of body O2 consumption, a figure three times higher than that for any other vertebrate studied, including man. The exceptionally high energetic cost of the G. petersii brain appears to be a consequence both of the brain being very large and of the fish being ectothermic. It was also found that G. petersii has a high ability to utilise O2 at low levels. Thus, during falling [O2], this species was found to maintain both its O2 uptake and its electric discharge rate down to an ambient O2 level of 0.8 mg l-1 (at 26 &deg;C), although it was unable to tolerate an [O2] below 0.3 mg l-1. During severe hypoxia (<0.8 mg l-1), G. petersii attempted to gulp air from the water surface. These results establish a new record for the energetic cost of a vertebrate brain and they show that the species possessing such a brain has a high capacity for utilising O2 at very low ambient concentrations.

This article has been cited by other articles:

				J. E. Niven and S. B. Laughlin Energy limitation as a selective pressure on the evolution of sensory systems J. Exp. Biol., June 1, 2008; 211(11): 1792 - 1804. [Abstract] [Full Text] [PDF]

				G. E. Nilsson, J.-P. A. Hobbs, and S. Ostlund-Nilsson Tribute to P. L. Lutz: respiratory ecophysiology of coral-reef teleosts J. Exp. Biol., May 15, 2007; 210(10): 1673 - 1686. [Abstract] [Full Text] [PDF]

				G. E. Nilsson, J.-P. Hobbs, P. L. Munday, and S. Ostlund-Nilsson Coward or braveheart: extreme habitat fidelity through hypoxia tolerance in a coral-dwelling goby J. Exp. Biol., January 1, 2004; 207(1): 33 - 39. [Abstract] [Full Text] [PDF]

				S. Schreiber, C. K. Machens, A. V. M. Herz, and S. B. Laughlin Energy-Efficient Coding with Discrete Stochastic Events Neural Comput., June 1, 2002; 14(6): 1323 - 1346. [Abstract] [Full Text]