1998 Fiscal Year Final Research Report Summary
Central control of spinal reflex circuits in normal subjects and patients with motor disorders of central origin.
| Project/Area Number |
08670701
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Neurology
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| Research Institution | Shinshu University |
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Principal Investigator |
MASAOMI Shindo Shinshu University Center for Health Services, Professor, 保健管理センター, 教授 (90020924)
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| Project Period (FY) |
1996 – 1998
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| Keywords | monosynaptic Ia facilitation / presynaptic inhibition / Ib inhibition / spasticity / Parkinson's disease / ageing / H-reflex / magnetic cortical stimulation |
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| Research Abstract |
1. lb inhibition in spastic patients : lb inhibition was studied at rest and during antagonist voluntary contraction in normal and spastic subjects. The extent of inhibition was normal in the patients. During contraction, the inhibition increased significantly in extent in normal subjects, whereas the increase was significantly less in the patients. In the patients without spastic gait, the inhibition increased to the normal extent, while it never increased in those with spastic gait. The extent of increase in inhibition was reversibly correlated with the walking time in the patients.
2. la facilitation & lb inhibition in normal ageing : Change in activities of monosynaptic la facilitation and lb inhibition with ageing was studied. These activities were assessed with the soleus H-reflex. In the resting state, la facilitation decreased in extent almost linearly with ageing, but lb inhibition did not show any change. The extent of increase in lb inhibition during antagonist contraction did not change during ageing process either. Decrease in la facilitation was considered to reflect increase in presynaptic inhibition on la terminals. Difference in the two pathways indicate a non-uniform change in reflex activities with ageing process, and these activity changes may be responsible for motor disturbances in elderly people.
3. Cortical activity in Parkinsonian patients : Cortical modulation of spinal motoneurones at voluntary contraction was studied in normal subjects and patients with Parkinson's disease. Magnetic cortical stimulation was applied to the motor cortex, and its effect on the soleus H-reflex was explored at rest and at soleus contraction. In normal subjects, a short latency inhibition was observed at rest, and at contraction, facilitation newly appeared with shorter latencies. In the patients, however, neither inhibition at rest nor facilitation at contraction was observed. These results may be caused by over-inhibition of the thalamo-cortical pathway.
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