1993 Fiscal Year Final Research Report Summary
Experimental study on the mechanism of pain induction in the reflex sympathetic dystrophy
| Project/Area Number |
04454385
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
麻酔学
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| Research Institution | NIIGATA UNIVERSITY |
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Principal Investigator |
SHIMOJI Koki Niigata University School of Medicine Professor, 医学部, 教授 (30040158)
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| Co-Investigator(Kenkyū-buntansha) |
HOKARI Tamaki Niigata University School of Medicine Assistant, 医学部附属病院, 助手 (10173577)
YOSHIMURA Megumu Kurume University School of Medicine Lecturer, 医学部, 講師 (10140641)
FUJIWARA Naoshi Niigata University School of Medicine Lecturer, 医学部附属病院, 講師 (70181419)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Refractory sensory nerve dystrophy / Sciatic nerve / Intracellular recording / Substantia gelatinosa neuron / Spinal cord potential / Supraspinal structures |
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| Research Abstract |
To investigate the mechanism of pain induction in reflex sympathetic dystrophy (RSD), we observed behaviors of RSD model rats and recorded neuronal activities of their spinal cord in vivo and in vitro. The RSD-model rats were prepa ; red by mechanical or chemical destruction of the sciatic nerve. Following the sciatic nerve destruction, abnormal behaviors such as biting the hind paws, running motion and paraplegia were observed. No abnormal behavior were observed in sham operated animal without the sciatic nerve destruction. In intracellular recording in the slice preparations of normal adult rats, monosynapotic EPSP and IPSP mediated by only the Asigma and C fibers, not by the Aalpha/beta fibers, werefound in substanitia gelatinosa neurons in respose to dorsal root stimulation. Polysynaptic postsynapyic potentials activated by Aalpha/beta fibers were recorded in a few substantia gelatinosa neurons. In the RSD model rats, monosynaptic potentials activated asigma and C fibers and polysynaptic inputs viaAalpha/beta fibers were observed in a majority of substantia gelatinosa neurons. Repetitive firings in substantia gelatinosa neurons were also observed following a dorsal root stimulation in slice preparations of the RSD model rats. Hetero-segmental spinal cord potentials consisted of two positive potentials (HSP1, HSP2) preceded by negatibe potentials were recorded at L4/5 in normal rats. There observed significant intensification in peak amplitude and elongation in duration in HSP1 and HSP2 in the RSD model animals. As these potentials might be produced by a feedback loop via supraspinal structures, abnormal neuronal excitation and intensification of the inhibitory potentials observed in the RSD model rats were thought to be mediated by segmental as well as supraspinal structures.
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Research Products
(14 results)
