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

This Article Figures Only 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 Moon, B. R. Articles by Urquhart, M. R. Search for Related Content PubMed PubMed Citation Articles by Moon, B. R. Articles by Urquhart, M. R. Social Bookmarking                         What's this?

The Journal of Experimental Biology 206, 1291-1297 (2003)
doi: 10.1242/jeb.00253

Minimal shortening in a high-frequency muscle

Brad R. Moon^1,*, Kevin E. Conley², Stan L. Lindstedt³ and Michael R. Urquhart³

¹ Department of Biology, PO Box 42451, University of Louisiana at Lafayette, Lafayette, LA 70504-2451, USA
² Department of Radiology, Box 357115, University of Washington Medical Center, Seattle, WA 98195, USA
³ Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA

^* Author for correspondence (e-mail: BradMoon{at}louisiana.edu)

Accepted 21 January 2003

Reducing the cost of high-frequency muscle contractions can be accomplished by minimizing cross-bridge cycling or by recycling elastic strain energy. Energy saving by contractile minimization has very different implications for muscle strain and activation patterns than by elastic recoil. Minimal cross-bridge cycling will be reflected in minimal contractile strains and highly reduced force, work and power output, whereas elastic energy storage requires a period of active lengthening that increases mechanical output. In this study, we used sonomicrometry and electromyography to test the relative contributions of energy reduction and energy recycling strategies in the tailshaker muscles of western diamondback rattlesnakes (Crotalus atrox). We found that tailshaker muscle contractions produce a mean strain of 3%, which is among the lowest strains ever recorded in vertebrate muscle during movement. The relative shortening velocities (V/V_max) of 0.2-0.3 were in the optimal range for maximum power generation, indicating that the low power output reported previously for tailshaker muscle is due mainly to contractile minimization rather than to suboptimal V/V_max. In addition, the brief contractions (8-18 ms) had only limited periods of active lengthening (0.2-0.5 ms and 0.002-0.035%), indicating little potential for elastic energy storage and recoil. These features indicate that high-frequency muscles primarily reduce metabolic energy input rather than recycle mechanical energy output.

Key words: tailshaker muscle, rattlesnake, Crotalus atrox, muscle contraction, elastic recoil, cross-bridge, biomechanics

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				C. P. H. Elemans, I. L. Y. Spierts, M. Hendriks, H. Schipper, U. K. Muller, and J. L. van Leeuwen Syringeal muscles fit the trill in ring doves (Streptopelia risoria L.) J. Exp. Biol., March 1, 2006; 209(5): 965 - 977. [Abstract] [Full Text] [PDF]