| Project/Area Number |
16591178
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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 |
Psychiatric science
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| Research Institution | NATIONAL INSTITUTE OF RADIOLOGICAL SCIENCES |
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Principal Investigator |
OBAYASHI SHIGERU NATIONAL INSTITUTE OF RADIOLOGICAL SCIENCES, DEPT. MOLECULAR NEUROIMAGING, MOLECULAR IMAGING CENTER, TEAM LEADER, 分子イメージング研究センター分子神経イメージング研究グループ, チームリーダー (90318246)
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| Co-Investigator(Kenkyū-buntansha) |
SUHARA TETSUYA NATIONAL INSTITUTE OF RADIOLOGICAL SCIENCES, MOLECULAR NEUROIMAGING, GROUP LEADER, 分子イメージング研究センター分子神経イメージング研究グループ, グループリーダー (90216490)
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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 |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2006: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2005: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2004: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | positron emission tomography(PET) / macaque monkeys / drug addiction / plasticity / dopamine / マイクロダイアリシス法 |
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| Research Abstract |
In this research project, we sought to explore the neurochemical mechanism underlying drug addiction using in vivo positron emission tomography (PET) with awake monkeys in combination with some invasive techniques. In the first year, we used microdialysis technique to investigate the neurochemical changes in the ventral striatum such as necleus accumbense by repetitive metamphetamine administration. The preliminary study suggested that the increase in methamphetamine-induced extracellular dopamine release would be augmented exponentially every methamphetamine exposure. In the second year, we investigated the long-term changes in the dopamine system caused by chronic exposure to the above addictive drug in an awake treated monkey using PET with [^<11>C]NNC112 and [^<11>C]FLB457. Our preliminary data suggested that the dopamine D1 receptor availability quantified by PET measurement with [^<11>C]NNC112 was decreased in PFC, whereas the dopamine D2 availability quantified by PET measurement with [^<11>C]FLB457 was increased in thalamus. In the last year, unfortunately, due to an accident bitten by monkey, we are forced to interrupt all of our monkey studies in our institute for 8 months till our study with monkeys was restarted. Meanwhile, we developed a intra-venous self-administration system for monkeys that could quantify the values of craving for the drug by counting lever responses. We are now training the task where monkeys can get food rewards or experience cocaine exposure when reaching a criteria by pressing a lever in front of the abdomen. The monkeys can recognize by visual cues which one of reward monkeys would be avialable. We expect that we can detect the neural basis underlying craving for cocaine by contrasting between regional CBF measured by PET with 0-15 labeled water during food reward condition and cocaine condition in the near future.
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