Anatomical and Physiological Studies on Interneurons Mediating the Inhibitory Effects of Exercise on Shivering in Pigeon Pectoral Muscles.
| Project/Area Number |
63570084
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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 |
環境生理学(含体力医学･栄養生理学)
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| Research Institution | Tokyo Metropolitan Institute of Gerontology |
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Principal Investigator |
NOMOTO Shigeki Tokyo Metropolitan Institute of Gerontology, Department of Central Nervous System, Research Scientist, 中枢神経部門, 研究員 (70125235)
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| Project Period (FY) |
1988 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1990: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1989: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1988: ¥900,000 (Direct Cost: ¥900,000)
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| Keywords | Shivering / Exercise / Pigeon / N. reticularis parvocellularis / Interneuron / Transsynaptic transport / WGA-HRP / WGA / 胸筋 / Nucleus reticularis parvocellularis / 一次求心性線維 / 誘発電位 / 背髄 / 運動ニューロン / WGA-HRP / transneuronal transport |
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| Research Abstract |
Shivering in the pectoral muscle of pigeons is inhibited immediately after beginning of treadmill exercise. Similar inhibition could be observed when one of the hind limb muscle was stimulated electrically. So it was suggested that primary afferent imputs from the muscle induce the inhibition. I have examined that primary afferent fibers of M. fibularis longus terminated in the dorsal horn of the spinal segments between T3 and S4 and that motoneurons of M. pectoralis located in the ventral horn of the spinal segments between C12 and C14. Consequently, the pectoral motor nucleus did not overlap the terminal fields of fibular muscle afferents. The inhibitory effects are mediated by interneurons located between these two regions.
In the present study,
1. I labeled the interneurons terminating to the pectoral motoneurons by means of transsynaptic transport of WGA-HRP and WGA in pigeons. Labeled interneurons were found in Nucleus reticularis parvocellularis (Rpc) in the lateral reticular formation bilaterally. No labeled interneurons were found in the spinal cord.
2. I examined the role of Rpc neurons on shivering in the pectoral muscle. Shivering was suppressed when Rpc was stimulated strongly (5-10V) with the onset latency of less than 10 msec. The onset latency of shivering inhibition was about 15 msec when the fibular muscle was stimulated. So it was suggested that Rpc neurons were mediating the inhibition of shivering.
3. I studied the fibular muscle afferent fibers mediating the inhibition of shivering and the terminal field in the spinal cord by recording evoked field potentials. The conduction velocity of fibular muscle afferent fibers coincided with group II fibers of mammals, and these fibers terminated mainly in lamina IV of the L4 spinal segment.
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Report
(4 results)
Research Products
(22 results)
