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This article is part of the supplement: Sixteenth Annual Computational Neuroscience Meeting: CNS*2007

Open Access Poster presentation

Role of the semi-lunar process in locust jumping

David W Cofer1*, James Reid2, Ying Zhu2, Gennady Cymbalyuk3, William J Heitler4 and Donald H Edwards1

Author Affiliations

1 Department of Biology, Georgia State University, Atlanta, GA 30303, USA

2 Computer Science, Georgia State University, Atlanta, GA 30303, USA

3 Physics and Astronomy, Georgia State University, Atlanta, GA 30303, USA

4 School of Biology, Univ. of St. Andrews, UK

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BMC Neuroscience 2007, 8(Suppl 2):P12  doi:10.1186/1471-2202-8-S2-P12

The electronic version of this article is the complete one and can be found online at:


Published:6 July 2007

© 2007 Cofer et al; licensee BioMed Central Ltd.

Poster presentation

The biomechanical and neural components that underlie locust jumping have been extensively studied [1-4]. Previous research suggested that energy for the jump is stored primarily in the extensor apodeme and in the semi-lunar process (SLP) [5], a thickened band of cuticle at the distal end of the tibia. As it has thus far proven impossible to experimentally alter the SLP without rendering a locust unable to jump, it has not been possible to test whether the energy stored in the SLP has a significant impact on the jump, or how that energy is applied during the jump.

To address problems such as this we have developed a software toolkit, AnimatLab, which allows researchers to build and test virtual organisms. We used this software to build a virtual locust, and then asked how the SLP is utilized during jumping, and how manipulation or removal of the virtual SLP influences jump dynamics (figures 1 and 2). The results show that without the SLP the jump distance was reduced by almost half. Further, the simulations were also able to show that loss of the SLP had a significant impact on the final phase of the jump impulse which prevented the full extension of the tibia against the ground. Power for the jump during the initial phase was almost identical between the two cases, but without the SLP the power peaked early and there was a significant difference in the power for the late phase of the jump.

thumbnailFigure 1. Percentage reduction in jump distance without semilunar process. Loss of the SLP reduced the distance jumped by approximately 45% across the entire range of extensor tensions tested. Each point is n = 20.

thumbnailFigure 2. Power during jump impulse. The power during the early phase of the jump is almost identical, but without the SLP it peaks early and the power from the late phase of the jump is almost entirely missing. This has a significant impact on the jump distance.

Acknowledgements

This project is supported by GSU Brains & Behavior Program and NIH Grant P20-GM065762.

References

  1. Heitler W: The locust jump.

    J Comp Physiol 1974, 89:93-104. Publisher Full Text OpenURL

  2. Heitler WJ, Burrows M: The locust jump. II. Neural circuits of the motor programme.

    J Exp Biol 1977, 66:221-241. PubMed Abstract | Publisher Full Text OpenURL

  3. Heitler WJ, Burrows M: The locust jump. I. The motor programme.

    J Exp Biol 1977, 66:203-219. PubMed Abstract | Publisher Full Text OpenURL

  4. Bennet-Clark HC: The energetics of the jump of the locust Schistocerca gregaria.

    J Exp Biol 1975, 63:53-83. PubMed Abstract | Publisher Full Text OpenURL

  5. Burrows M, Morris G: The kinematics and neural control of high-speed kicking movements in the locust.

    J Exp Biol 2001, 204:3471-3481. PubMed Abstract | Publisher Full Text OpenURL