| Project/Area Number |
01570609
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Psychiatric science
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| Research Institution | Kochi Medical School |
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Principal Investigator |
IKEDA Hisao Kochi Medical School, Department of Neuro-psychiatry, Professor, 医学部, 教授 (90033076)
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| Co-Investigator(Kenkyū-buntansha) |
OKADA Michiyuki Kochi Medical School, Department of Neuro-psychiatry, Assistant, 医学部, 助手 (20224024)
YAMASHITA Motoshi Kochi Medical School, Department of Neuro-psychiatry, Instructor, 医学部, 講師 (30174684)
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| Project Period (FY) |
1989 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1991: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1990: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1989: ¥800,000 (Direct Cost: ¥800,000)
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| Keywords | Dementia / Animal model of dementia / Medial septum lesion / Basal nucleus lesion / 8-aum radial maze / Water maze / アルツハイマ-型老年痴呆 / 水迷路課題 |
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| Research Abstract |
In order to establish the experimental systems for studying a pathophysiology and recovery process of dementia, many kinds of neurotoxic drugs for making a lesion in the cholinergic systems in the brain, and tasks for evaluating the learning ability of an animal were studied with the following results.
Hypofunction of cholinergic systems as a neurochemical finding and spatial disorientation as a clinical symptoms are well known characters of Alzheimer's disease. These findings were reproduced in animals to make an animal model of dementia.
Ibotenic acid or AF64A were injected into medial septum (MS) or nucleus basalis of Magnocellularis (NBM). The effects of cholinergic hypofunction on spatial memory were assessed in water maze (Morris, 1981). After injection of ibotenic acid into NBM, escape latency was significantly increased. Transfer test also showed significant increase of time to stay in the area where platform was once placed. MS lesion combined with unilateral lesion of NBM by AF64A significantly increased escape latency. And furthermore, escape latency was longer after 24 hour interval compared to ten minutes interval. These results show the function of MS cholinergic system in long term and short term memory. Even unilateral lesion of NBM significantly impaired acquisition of spatial memory.
To our knowledge, radial maze task was a potent task to assess MS cholinergic hypofunction but was not a potent task to assess NBM cholinergic hypofunction. But these results showed that water maze is a useful task to access, especially NBM cholinergic system.
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