| Project/Area Number |
17580275
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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 |
Clinical veterinary science
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| Research Institution | Tokyo University of Agriculture (2006)
Hokkaido University (2005) |
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Principal Investigator |
NIWA Koichi (2006) Tokyo University of Agriculture, Faculty of Bioindustry, Associate Professor, 生物産業学部, 助教授 (20301012)
浅沼 武敏 (2005) 北海道大学, 大学院・獣医学研究科, 助手 (40332473)
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| Co-Investigator(Kenkyū-buntansha) |
HIRAOKA Wakako Meiji University, Department of Science and Technology, Associate Professor, 理工学部, 助教授 (00212168)
ASANUMA Taketoshi Hokkaido University, Graduate School of Veterinary Medicine, Research Associate, 大学院・獣医学研究科, 助手 (40332473)
KITAMURA Naoki Tottori University, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (80301951)
丹羽 光一 東京農業大学, 生物産業学部, 助教授 (20301012)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2005: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | neuropathic pain / fMRI / BOLD / anterior cingulated cortex / somatosensory cortex / rat / brain / pain / ホルマリン / 前帯状皮質 / モルヒネ |
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| Research Abstract |
In this study, the possibility that functional MRI (fMRI) method can non-invasively visualize a response of pain was examined in rat cerebral cortex. In order to demonstrate that blood oxygen level dependent (BOLD) signal changes actually reflect the pain in the cerebral cortex, we compared BOLD-signals with morphine with those without morphine.
Experiment was performed using a 7.05 Tesla superconducting MRI system and a one-turned surface coil centered over the primary somatosensory cortex in cerebral cortex of rat under the mechanical ventilation. A set of multi-slice gradient echo images was acquired and analyzed using commercially available software for imaging analysis (MEDx). Isoflurane provided the stable anesthesia level and the favorable results concerning the fMRI in rat cerebral cortex. Following the subcutaneous injection of 50 μl of formalin or capsaicin into the left forepaw, a regional increase in the signal intensity in the MR images was observed in all rats.
Formalin stimulation to the left forepaw of rat displayed that the signal increase was observed in contralateral somatosensory cortex and both anterior cingulated cortexes following its injection, it was maintained for 4 minutes. Furthermore, the continuous but weak signal increase in signal was observed for 20 minutes after stimulation. Pre-treatment with morphine vanished these responses. Capsaicin stimulation in left forepaw displayed that the signal increase was observed immediately after stimulation, but the signal disappeared within one minute. Pre-treatment with morphine vanished these responses in a similar fashion to the formalin stimulation.
This BOLD-fMRI technique in anesthetized animal brain is a useful way to study the mechanism of pain and assess new analgesics.
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