1990 Fiscal Year Final Research Report Summary
Neurophysiological Analysis of Spinoderebellar Tract Neurones of the Thoracic Segments in Relation to Respiratory Movement
| Project/Area Number |
01570077
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Neurophysiology and muscle physiology
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| Research Institution | Kyorin University |
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Principal Investigator |
HIRAI Naoki Kyorin University School of Medicine Dept. Physiol., Professor, 医学部, 教授 (40086583)
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| Co-Investigator(Kenkyū-buntansha) |
TANAKA Yuji Nihon University School of Medicine Dept. Physiol., Lecturer, 医学部, 助手 (40179792)
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| Project Period (FY) |
1989 – 1990
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| Keywords | Spinocerebellar tract / Spinal cord / Cerebellum / Respiration / Motor control |
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| Research Abstract |
In each spinal segment, there exist two grtoups of spinocerebellar tract (SCT) neurones ; one having uncrossed and the other crossed ascending axons. To see if there is a functional difference between them, the kind of information transmitted to the cerebellum through uncrossed and crosses SCTs was examined in the thoracic segments during respiration. Recordings of activity of uncrossed and crossed SCT neurones identified by antidromic activation from the cerebellum and upper cervical spinal cord were made in the cat anesthetized with pentobarbital sodium (35mg/Kg), and artificially ventilated after being paralyzed with pancuronium bromide. Rhythmic respiratory movement was monitored by recording phrenic nerve activity (reflecting central respiratory rhythm) and by thorax movement.
Thirty four SCT neurones showed rhythmic activities in relation to some aspects of respiration. Neural activity of 22 uncrossed SCT neurones located in mainly the Clarke's column was locked to the respiratory pump cycle. Because this rhythmicity still remained even after vagotomy, but disappeared after pneumothorax, rhythmic activity of uncrossed SCT neurones may be caused by inflow from the chest wall. On the other hand, rhythmic activity of crossed SCT neurones remained and coincided with the phrenic nerve activity even after pneumothorax, suggesting the central genesis of the rhythmcity.
During spontaneous respiration, rhythmic activity of some crossed SCT neurones, which was clearly seen under artificial ventilation, became weak or disappeared, suggesting that crossed SCT may integrate central and peripheral inputs.
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