2000 Fiscal Year Final Research Report Summary
Response properties of thalamic neurons in the rats with experimental mononeuropathy -the role of the dorsal column -thalamic pathway-
| Project/Area Number |
11671857
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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 |
Functional basic dentistry
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| Research Institution | Nihon-University |
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Principal Investigator |
TSUBOI Yoshiyuki Nihon-University, School of Dentistry, Physiology, Assitant Professor, 歯学部, 講師 (50246906)
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| Co-Investigator(Kenkyū-buntansha) |
KONDO Eiji Hyogo College of Medicine, Anatomy and Neuroscience, Assistant Professor, 医学部, 講師 (50273636)
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| Project Period (FY) |
1999 – 2000
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| Keywords | CCI / rat / VPL / hyperalgesia / dorsal column / gracile nucleus / CNOX / MK-801 |
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| Research Abstract |
We examined the involvement of the dorsal column-thalamic pathway in changes the response properties of thalamic neurons in the rats with experimental mononeuropathy We recorded from the ventro-postero-lateral nucleus of thalamus (VPL) in rats with chronic constriction nerve injury (CCI), and examined the effects of the lesion of the dorsal column (DC) -thalamic pathway and the administration of the glutamate receptor antagonists (CNQX, MK801) to the gracile nucleus (GN) on the response properties of VPL neurons. The following results were obtained from this study.
1. In the lesion study, responses of low threshold mechanoreceptive (LTM) and wide dynamic range (WDR) neurons to innocuous mechanical stimulation to the receptive fields were significantly decreased after DC and DC+GN lesions. However, the responses of WDR neurons to noxious stimuli were selectrons in the VPL nucleus contralateral to CCI side after DC and DC+GN lesions was grater than that in the VPL nucleus contralatral to the sham operated side and naive.
2. In the administration study, the evoked responses of WDR neuron, in the VPL nucleus contralateral to CCI side, to the graded mechanical stimulation were dose-dependently depressed after application of CNQX on GN pool. The evoked responses of WDR neuron, in the VPL nucleus contralateral to CCI side, to the noxious stimulation and background activity were dose-dependently depressed after application of MK-801.
We suggested that DC-pathway might take an important role in the development of mechanical hyperalgesia.
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