| Project/Area Number |
16591240
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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 |
Radiation science
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| Research Institution | National Institute for Environmental Studies |
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Principal Investigator |
WATANABE Hidehiro National Institute for Environmental Studies, Environmental Chemistry Division, Senior Researcher, 化学環境研究領域, 主任研究員 (60370269)
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| Co-Investigator(Kenkyū-buntansha) |
MITSUMORI Fumiyuki National Institute for Environmental Studies, Environmental Chemistry Division, Chief, 化学環境研究領域, 室長 (90125229)
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| Project Period (FY) |
2004 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2006: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2005: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2004: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | neurotransmitter / glutamate / GABA / MRI / high field / human brain / 2D spectroscopy / noninvasive / γ-アミノ酪酸 / ヒト / 脳 / CT COSY / MRS / 代謝物 / 興奮性神経伝達物質 / 抑制性神経伝達物質 / 無浸襲計測 |
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| Research Abstract |
Glutamate and GABA are major neurotransmitters in human brain. It is suggested that they have some relation with degenerative nerve diseases and psychiatric disorders. Then, these metabolites are one of the important subjects for ^1H MRS.
However, it is difficult to detect these metabolites in vivo, because they have JHH coupled spin systems. Due to this coupling and close chemical shifts, the features of these peaks are complicated and they are severely overlapped at clinical 1.5 T MR systems. Even at 3 T which are now applied to clinical fields, these difficulties are not enough improved.
The purpose of our studies was to detect and quantify glutamate and GABA in human brain in vivo simultaneously. First, we have developed new measurement methods for peak detection of glutamate and GABA in vivo. These peaks could be resolved on localized CT COSY spectra at 4.7 T in human brain. Next, ISIS CT COSY method has been developed to improve slice displacement error due to chemical shifts. This method also improves slice profile. Post processing methods have also developed to improve distortion along F_2 axis and artifacts along F_1 axis. Finally, we have developed a quantitation method on in vivo 2D spectra using ISIS CT COSY. This method consists of T_2 compensation of J_<HH> coupled spin systems and curve fitting of peak on 2D spectra. By this method, we have quantified glutamate and GABA simultaneously in human brain and these concentrations were calculated as 11.7 mM and 0.95 mM respectively. These values were within reported values.
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