Encyclopedia of Neuroscience

2009 Edition
| Editors: Marc D. Binder, Nobutaka Hirokawa, Uwe Windhorst

Postural Muscle Tone

  • Victor S. Gurfinkel
Reference work entry
DOI: https://doi.org/10.1007/978-3-540-29678-2_4711

Definition

Postural tone is the steady contraction of muscles that are necessary to hold different parts of the skeleton in proper relation to the various and constantly changing attitudes and postures of the body.

Description of the Theory

Decerebrate Posture

Because postural muscle tone is completely suppressed by narcosis, postural tone has mainly been studied using an experimental model called the decerebrate animal [1]. In the decerebration of mammals, the cerebral cortex and thalamus are surgically inactivated by intercollicular cross-section of the brain stem under general anesthesia. Once the effects of the anesthesia have dissipated, the condition known as “decerebrate rigidity” can be seen. This condition is characterized by a strong extended neck, trunk, tail and limbs, which resist attempts to flex them. In decerebrate rigidity, there is no sensation of pain. Because of this rigidity, when the decerebrate cat is placed on its four limbs, tension in the limb muscles is...

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References

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Copyright information

© Springer-Verlag GmbH Berlin Heidelberg 2009

Authors and Affiliations

  • Victor S. Gurfinkel
    • 1
  1. 1.Neurological Sciences InstituteOregon Health & Science UniversityPortlandUSA