| Project/Area Number |
17390518
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
補綴理工系歯学
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| Research Institution | OKAYAMA UNIVERSITY |
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Principal Investigator |
MINAGI Shogo Okayama Univ., Graduate School of Medicine, Dentistry & Pharmaceutical Sciences, Professor, 大学院医歯薬学総合研究科, 教授 (80190693)
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| Co-Investigator(Kenkyū-buntansha) |
HARA Tetsuya Okayama Univ., Graduate School of Medicine, Dentistry & Pharmaceutical Sciences, Associate Professor, 大学院医歯薬学総合研究科, 助教授 (60238160)
KINUTA Yoshihiro Okayama Univ., Graduate School of Medicine, Dentistry & Pharmaceutical Sciences, Assistant Professor, 大学院医歯薬学総合研究科, 助手 (50314696)
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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 |
¥15,100,000 (Direct Cost: ¥15,100,000)
Fiscal Year 2006: ¥6,000,000 (Direct Cost: ¥6,000,000)
Fiscal Year 2005: ¥9,100,000 (Direct Cost: ¥9,100,000)
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| Keywords | memory / activity / spaced learning / hippocampus / maze / rat |
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| Research Abstract |
The purpose of the present study was (1) to investigate the changes in spatial learning and memory by tooth loss and occlusal rehabilitation with denture prosthesis, (2) to reveal the effectiveness of theory of spaced learning to the memory. Male Wistar rats were trained on working memory task for 20 days on 8-arm radial maze. After habitation trial, the massed learning group received 8 trials every 5 days. On the contrary, the trial was received twice every 5, 10, 15, and 20 days in the spaced learning group. All groups received the last trial to evaluate the loss of a spatial memory 20 days after these trials. The total number of errors and the time taken to finish the trial were analyzed by ANOVA. Following completion of these behavioral tests, histological investigation was carried out by pyramidal cell count of tissue samples (Nissl staining).
The massed learning showed significant increase of the number of errors between the eighth and ninth task, but spaced learning didn't show the decrease of the memory. In the ninth task of massed learning groups, hypomnesia progressed in toothless group compared to the other groups. The time was showing a tendency to rise as time passed. The number of hippocampus pyramidal cells in CA1 and CA4 region decreased in order of control, occlusal rehabilitation and toothless groups.In conclusion, tooth loss progressed the decline of the spatial memory, and the occlusal rehabilitation recovered the memory. And it was indicated that the spaced learning would elude the loss of spatial memory compared with massed learning.
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