| Project/Area Number |
08670012
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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 |
General anatomy (including Histology/Embryology)
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| Research Institution | YAMANASHI MEDICAL UNIVERSITY |
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Principal Investigator |
ATSUMI Saoko Yamanashi Medical University, Department of Anatomy, Professor, 医学部, 教授 (10110298)
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| Co-Investigator(Kenkyū-buntansha) |
KAWATE Toyoko Yamanashi Medical University, Department of Anatomy, Research Associate, 医学部, 助手 (10252024)
SAKAMOTO Hiroshi Yamanashi Medical University, Department of Anatomy, Research Associate, 医学部, 助手 (10162314)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1997: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1996: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | spinal cord / primary afferent fiber / synaptic glomerulus / pain / enkephalin / substance P / GABA / glycine / 免疫細胞化学 |
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| Research Abstract |
The aim of this study is to elucidate the neural circuitry between terminals of nociceptive primary afferents and long ascending tract neurons, and inhibitory control mechanism of pain transmission in the dorsal horn of the chicken by morphological techiniques. The following results were obtained in 1996 and 1997.
1. Neural circuitry from primary afferents to long ascending tract cells. (1) Presumable long ascending tract cells which received nemerous substance P (SP)-containing axon terminals were distributed in the laminae I and II throughout the spinal cord and observed once in every 50mum. (2) In chickens which had been given backskin-cut in either side of the body to give chronic pain, time course of SP-immunoreactivity (IR) in the dorsal horn was examined. The SP-IR changed diphasically ; it decreased immediately after skin-cut, then increased, next decreased, and then increased and finally gradually returned to the original level.
2. Inhibitory mechanism of pain sensation at the d
… More
orsal horn level. (1) In the synaptic glomerulus, glycine-containing elements made synapses with the central terminal of the primary afferents. Some glycine terminals coexisted with GABA.(2) Enkephalin (Enk)-containing elements in the synaptic glomerulus were demonstarated to be vesicle-containing dendrites by the double labeling technique using antiMAP2 and antiEnk antibodies. (3) The structure of synaptic glomeruli was examined by the freeze-fracture technique. On the P face of the central terminal, the characteristic feature of presynapic P face (dimples and surrounding intramembrane particles (IMPs)) was observed adjacent to aggregate of IMPs which was characteristic to the postsynaptic membrane, suggesting the presence of reciprocal synapses.
3. As to terminals of primary afferents, HRP was injected in the spinal ganglion. Labeled unmyelinated and thin myelinated fibers were examined by electron microscopy. These formed the central terminal in the synaptic glomerulus. A part of the labeled central terminals showed SP-IR. Less
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