Stroboscopic Cinematographic and Videorecording of Dynamic Bag1 Fibres During Rapid Stretching of Isolated Cat Muscle Spindles

  • I. A. Boyd
  • M. H. Gladden
  • D. Halliday
  • M. Dickson

Abstract

When an isolated cat muscle spindle is subjected to a ramp and hold stretch the primary sensory annulo-spiral round the dynamic bag1 (Db1) fibre is extended and then creeps back part way towards its original state over several seconds since the poles of the fibre give way (Boyd, 1976). This ‘creep’ at the final length is small, or absent, when the fibre is inactive, and is greatly enhanced by activation of the fibre (Fig. 1; Boyd, Gladden & Ward, 1981). The length sensitivity of the primary sensory ending is greatly increased during the dynamic phase of stretching, but the static length sensitivity is little increased because the creep causes pronounced slow adaptation of the Ia discharge (Fig. 2).

Keywords

Muscle Spindle Sarcomere Length Fluid Space Intrafusal Fibre Stretch Activation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Boyd, I. A., 1976, The mechanical properties of dynamic nuclear bag fibres, static nuclear bag fibres and nuclear chain fibres in isolated cat muscle spindles, Prog. Brain Res., 44:33–50.PubMedCrossRefGoogle Scholar
  2. Boyd, I. A., and Gladden, M. H., 1985, “The Muscle Spindle”, Macmillan, London.Google Scholar
  3. Boyd, I. A., Gladden, M. H., and Ward, J., 1981, The contribution of mechanical events in the dynamic bag., intrafusal fibre in isolated cat muscle spindles to the form of the Ia afferent axon discharge, J. Physiol., 317:80–81P.Google Scholar
  4. Poppele, R. E., 1985, Relation between intrafusal muscle mechanics and the sensitivity of spindle sensory endings, in: “The Muscle Spindle”, pp.167–171, I. A. Boyd and M. H. Gladden, eds., Macmillan, London.Google Scholar
  5. Poppele, R. E., and Quick, D. C., 1981, Stretch induced contraction of intrafusal fibres in the cat muscle spindle, J. Neurosci. 1:1069–1174.PubMedGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1988

Authors and Affiliations

  • I. A. Boyd
    • 1
  • M. H. Gladden
    • 1
  • D. Halliday
    • 1
  • M. Dickson
    • 1
  1. 1.Institute of PhysiologyUniversity of GlasgowGlasgowUK

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