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Volume 28 (1979)
- Issue 4 Pages 299-
- Issue 3 Pages 239-
- Issue 2 Pages 81-
- Issue 1 Pages 1-
Volume 28, Issue 4
Displaying 1-3 of 3 articles from this issue
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TATSUYA KASAI, YOSHIBUMI NAKAHARA1979 Volume 28 Issue 4 Pages 299-306
Published: December 01, 1979
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSIt has been shown that there were the changes of H-reflex prior to the rapid voluntary movement. The present paper is designed to examine the changes of H-reflex about the time course prior to the rapid voluntary movement (dorsiflexion and plantarflexion), and premotor silent period in detail.
H-reflexes were elicited from subjects' right foot at varying intervals after the response signal (sound stimulus) of reaction time task when the response involved the rapid dorsiflexion or plantarflexion of the foot. In plantarflexion, H-reflexes were elicited from two response situations ; one was the situation which subjects were not given the preparatory stimulus (without warning = W -), the other was given the preparatory stimulus (with warning= W+) .
The following results were obtained ;
1) Dorsiflexion and plantarflexion
In case of dorsiflexion, although there were no obvious changes of H-reflex prior to EMG onset, in case of plantarflexion the damping phenomenon of H-reflex prior to EMG onset was observed and this phenomenon was the inhibitory one. Especially, under w-situation, it was obviously and it was about 70-80msec prior to EMG onset.
2) Silent period
The damping phenomenon of H-reflex was observed in accordance with silent period but this value was much the same of control level. This value of the damping of H-reflex was smaller than that of premotor silent period (about 30-40msec) . The time when the damping of H-reflex was observed was in accordance with that of prior to EMG onset of simple plantarflexion and this damping of H-reflex was the inhibitory phenomenon.
These results suggest that the upper center sents some inhibitory motor commands to cotralateral agonist motorneurons in advance of the voluntary movement in spite of the peripheral motor set, and those from the upper center precede the voluntary movement by ahnnt 70-80msec.View full abstractDownload PDF (934K) -
SHUKICHIRO NAKAMURA1979 Volume 28 Issue 4 Pages 307-313
Published: December 01, 1979
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSStroke-prone spontaneously hypertensive rats (SHRSP), which were separated from spontaneously hypertensive rats (SHR), have had a high incidence (more than 900) of cerebrovascular lesions (stroke) spontaneously, and are regarded as a model animal for the study of essential hypertension and stroke in man.
The present study was undertaken to analyse the effect of long-term running, using the treadmill with an electroshocker designed by Fujiwara, on the blood pressure, incidence of stroke and average age of death in SHRSP. After the rats lost their ability to continue the running on the treadmill, they were taken in the sloping cage designed by the author in order to exercise as long as they could.
When the load of running was adjusted according as individual coditions of rats, the blood pressure elevation were considerably delayed, and their life span were considerably elongated. The exercise started at six weeks of age seemed to be more effective than that at ten weeks of age. But there was no difference in the incidence of stroke between the running group and the control group in SHRSP.View full abstractDownload PDF (765K) -
1979 Volume 28 Issue 4 Pages 325-406
Published: December 01, 1979
Released on J-STAGE: September 30, 2010
JOURNAL FREE ACCESSDownload PDF (12095K)
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