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A Cerebellar-dependent Efference Copy Mechanism for Generating Appropriate Muscle Responses to Limb Perturbations

  • J. Hore
  • T. Vilis
Part of the Proceedings in Life Sciences book series (LIFE SCIENCES)

Abstract

The generation of appropriate muscle responses to a limb or body perturbation requires correct prediction of the nature and consequences of the perturbation. For example, Nashner (1976) demonstrated that the same stretch of the ankle extensors elicited different muscle responses depending on the postural situation in which this stretch occurred. Given a few trials the responses could be altered such That they were appropriate for maintaining postural stability. Thus training can be used to set up stretch reflexes such that they are context-specific. Motor responses can also be altered by prior instruction or intent. Hammond (1956) showed that the muscle response to stretch could be modulated in magnitude depending on whether the subject intended to resist or give way to the stretch. How does motor set, whether mediated by training or prior instruction, modify the muscular response to stretch? One possibility is that set can modulate or gate the synaptic efficacy of stretch reflexes. In the case of Nashner’s experiment reflex loops could be modulated or even opened or closed depending on the motor set. Another possibility is that set allows the preprogramming of the appropriate response which then is triggered or released by the initial stretch. This mode is suggested in the experiments of Evarts and Tanji (1976) which dissociated reflex from intended muscle activity. Here set-dependent activity in both muscle and motor cortex was triggered by a perturbation independent of the direction of the initial stretch.

Keywords

Motor Cortex Antagonist Muscle Muscle Response Stretch Reflex Return Movement 
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. Bantli H, Bloedel JR (1976) Characteristics of the output from the dentate nucleus to spinal neurons via pathways which do not involve the primary sensorimotor cortex. Exp Brain Res 25: 199–220 EcclesGoogle Scholar
  2. Eccles JC (1979) Introductory remarks. In: Massion J, Sasaki K (eds) Cerebro-cerebellar interactions. Elsevier/North-Holland, Biomedical Press, AmsterdamGoogle Scholar
  3. Evarts EV (1973) Motor cortex reflexes associated with learned movement. Science 179: 501–503PubMedCrossRefGoogle Scholar
  4. Evarts EV, Tanji J (1976) Reflex and intended responses in motor cortex pyramidal tract neurons of monkey. J Neurophysiol 39: 1069–1080PubMedGoogle Scholar
  5. Flament D, Hore J, Vilis T (1984) Dependence of cerebellar tremor on proprioceptive but not visual feedback. Exp Neurol 94: 314–325CrossRefGoogle Scholar
  6. Hammond PH (1956) The influence of prior instruction to the subject on an apparently involuntary neuro-muscular response. J Physiol 132: 17P - 18 PGoogle Scholar
  7. Helmholtz HV (1910) Handbuch der physilogischen Optik, vol III. Leopold Voss, Hamburg Leipzig Hore J, Vilis T (1984) Loss of set in muscle responses to limb perturbations during cerebellar dysfunction. J Neurophysiol 51: 1137–1148Google Scholar
  8. Marsden CD, Merton PA, Morton HB, Hallett M, Adam J, Rushton DN (1977) Disorders of movement in cerebellar disease in man. In: Rose F (ed) The physiological aspect of clinical neurology. Blackwell, Oxford, pp 179–199Google Scholar
  9. Nashner LM (1976) Adapting reflexes controlling the human posture. Exp Brain Res 26: 59–72PubMedCrossRefGoogle Scholar
  10. Phillips CG, Porter R (1977) Corticospinal neurones. Academic Press, London New YorkGoogle Scholar
  11. Strick PL (1983) The influence of motor preparation on the response of cerebellar neurons to limb displacements. J Neurosci 3: 2007–2020PubMedGoogle Scholar
  12. Thach WT (1972) Cerebellar output: properties, synthesis and uses. Brain Res 40: 89–97PubMedCrossRefGoogle Scholar
  13. Vilis T, Hore J (1980) Central neural mechanisms contributing to cerebellar tremor produced by limb perturbations. J Neurophysiol 43: 279–291PubMedGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1984

Authors and Affiliations

  • J. Hore
  • T. Vilis
    • 1
  1. 1.Department of PhysiologyUniversity of Western OntarioLondonCanada

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