1994 Fiscal Year Final Research Report Summary
Analysis of cerebrofugal inputs to the medullary and upper cervical respiratory neurons.
| Project/Area Number |
05680701
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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 |
Neuroscience in general
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| Research Institution | SAPPORO MEDICAL UNIVERSITY |
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Principal Investigator |
AOKI Mamoru Sapporo Medical University, School of Medicine, Department of Physiology, Professor, 医学部, 教授 (50001871)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAZONO Yoshimi Sapporo Medical University, School of Medicine, Department of Physiology, Instru, 医学部, 助手 (30180300)
SATOMI Hajime Sapporo Medical University, School of Medicine, Department of Physiology, Assist, 医学部, 講師 (10045445)
FUJITO Yutaka Sapporo Medical University, School of Medicine, Department of Physiology, Assist, 医学部, 講師 (40133144)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Cervical respiratory neuron / Cerebrofugal input / Corticospinal tract / Rubrospinal tract / Phrenic nucleus / Cat / PHA-L |
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| Research Abstract |
Cerebrofugal inputs to the brainstem-spinal cord respiratory neural structures were investigated by use of electrophysiological and histological methods in the period from 1993.4 to 1995.3. Following important findings were obtained. In the first year, corticospinal effects were analyzed by microstimulations (below 100muA) of the sensory motor cortex or the cerebral peduncle in the cat. This stimulation produced the short latency facilitation followed by inhibitory effects on upper cervical respiratory neurons and phrenic motoneurons. Stimulation of the red nucleus produced no observable effects on these neurons and in several experiments, there occurred only slight facilitatory effects on phrenic motoneuron discharge.
In the following years, histological identification of the descending tracts were attempted. A small amount of PHA-L was injected to the sensory-motor cortex and the distribution of anterogradely labeled fibers were traced. Labeled fibers were specifically distributed to the intermediate gray matter of the upper cervical segments (C1-C2) and also in the intermediate gray matter and in the phrenic motor nucleus of the lower cervical segments (C5-C6).
These results suggest that cerebrofugal inputs, especially the corticospinal tract plays an important role in the brainstem-spinal cord respiratory neural mechanisms.
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