J.Jpn. Surg. Soc.. 58(8): 1205-1216, 1957
EXPERIMENTAL STUDIES ON THE CHRONAXY RATIO OF THE ANTAGONITIC MUSCLES BY THE LESION ON THE CEREBEELUM.
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First Department of Surgery, Osaka University Medical School (Director: Dr. Y. Ozawa) Yukio BABA |
Recently, the author found this ratio became 1: 1 on patients with cerebellar tumor. This fact leads the author to investigate the important role of cerebellar function on the control mechanism of this chronaxy ratio. Therefore, experimental researches have been performed to study the influences of cerebellar lesions on this ratio, systematically stimulating and destructing on each portion of the cerebellum of rabbit respectively. The chronaxy of antagonistic muscles was measured on the M. tibialis anterior (longer chronaxy) and on the M. gastrocnemius (shorter chronaxy). There were observed two modes of the influence by cerebellar lesions on this ratio, however, they both showed 1: 1.
(1) 1 : 1 was due to the increase of the shorter chronxy in the case of lesion of the following parts :
a) Hemisphaerium cerebelli,
b) Lobulus petrosus,
c) Nucl. dentatus and
d) Brachium conjunctivum.
(2) 1 : 1 was due to increase of shorter chronaxy and, at the same time, decrease of the longer chronaxy.
e) Vermis,
f) Nucl. fastigii and
g) Corp. restiforme.
Formerly, lesion of the crus cerebri showed the same attitude as (1) and at the next stage of the investigation the author tested the relationship between these same two tendencies. Partial resection of the cortex was performed on this point of view.
Resection of the motor cortex or parietal, occipital part did not influenced on this mechanism, but the resection of the frontal and temporal part induced the shorter chronaxy increased, which caused chronaxy ratio 1: 1.
These results are considered that the control mechanism of chronaxy ratio is influenced by the corico-ponto-cerebellar system. On the other hand, the reticular formation, vestibular organ, spinal cord and peripheral sensory nerves correspond as (2) and these results are considered that these systems are being connected through the corpus restiforme.
(author's abstract)
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