NEURO- MUSCULAR ORGANIZATION 
OF SHIVERING 
Yojiro Kawamura 
Department of Physiology 
University of Osaka 
Osaka, Japan 
Shivering in response to a cold stress normally waxes and 
wanes in intensity. Studying patterns of muscular activity at different 
levels of such intensity is a method of investigating certain neural 
aspects of shivering. In this experiment jaw and limb muscles were 
analyzed electromyographically during shivering and the effects of 
some physiological variables on such activity were noted. 
EXPERIMENTAL PROCEDURE 
Thirty-five male and female adult dogs (9.0 - 11.5 kg.) were 
anesthetized with sodium isoamytal barbiturate (0.6 mg/kg I. V.) 
and electromyograms of jaw, fore and hind limb flexor and extensor 
muscles were recorded simultaneously while the animals were 
shivering in the waning stages of anesthesia. The animals were not 
restrained, but rather positioned in normal sleeping posture. The 
electromyograms were recorded with a concentric bipolar electrode, 
C-R coupledamplifier,cathode ray oscilloscope and electromagnetic 
oscillograph. Respiratory movements were recorded by strain 
gauge transduction of pressure variation of a chest tambour. Shiv- 
ering movements were additionally recorded by strain gauge trans- 
duction of limb vibrations. 
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