| Project/Area Number |
10680762
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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 |
神経・脳内生理学
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| Research Institution | TOYAMA MEDICAL AND PHARMACEUTICAL UNIVERSITY |
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Principal Investigator |
NISHIJO Hisao Faculty of Medicine, Professor, 医学部, 教授 (00189284)
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| Co-Investigator(Kenkyū-buntansha) |
HORI Etsuro Faculty of Medicine, TOYAMA MEDICAL AND PHARMACEUTICAL UNIVERSITY Assistant, 医学部, 助手 (90313600)
UMENO Katsumi Faculty of Medicine, TOYAMA MEDICAL AND PHARMACEUTICAL UNIVERSITY Assistant, 医学部, 助手 (90086596)
TABUCHI Eiichi Faculty of Medicine, TOYAMA MEDICAL AND PHARMACEUTICAL UNIVERSITY Assistant Professor, 医学部, 講師 (70272911)
EIFUKU Satoshi Faculty of Medicine, TOYAMA MEDICAL AND PHARMACEUTICAL UNIVERSITY Assistant, 医学部, 助手 (70262508)
TAMURA Ryoi Faculty of Medicine, TOYAMA MEDICAL AND PHARMACEUTICAL UNIVERSITY Associate professor, 医学部, 助教授 (60227296)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 1999: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1998: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | Place cells / Place fields / Cognitive map / Reference frame / Episodic memory / Hippocampal formation / Monkey / Cross correlation |
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| Research Abstract |
1. To investigate the role of the medial temporal lobe including the hippocampal formation (HF), and parahippocampal gyrus (PH) in spatial representaion of the outer world, neuronal activity in the HF, and PH was recorded from the monkeys. In the tasks the monkey freely moved to one of 4 reward areas in an experimental. field by driving a cab which the monkey rode (real translocation task), or freely moved a pointer to one of 4 reward areas on a monitor (virtual translocation task) by manipulating a joystick.
2. Of 389 neurons recorded from the monkey HF and PH, 166 had place fields which displayed increased activity in a specific area in the experimental field and/or on the monitor (location-differential neurons). These neurons had low mean spontaneous firing rates, similar to those of rodent HF place cells. The remaining non-responsive neurons had significantly higher mean firing rates, similar to interneurons or theta cells in the rodent HF. Furthermore, most location-differential ne
… More
urons showed different responses in different tasks. In addition, of 163 neuron pairs recorded simultaneously, significant cross-correlation (CCR) peaks were observed in 98 pairs. Task-selective CCRs were observed in 44% (43/98) of neuron pairs. These results suggest that the HF and PH are crucial in allocentric information processing and more over that the HF can encode different reference frames that are context or task-dependent. This may be the neural basis of episodic memory.
3. These 166 location-differential neurons were analyzed in terms of 16 places in the experimental field or on the monitor by means of the multidimensional scaling (MDS). In the real translocation tasks, the 16 places spread apart in two-dimensional space and their relative positions in a two-dimensional space were well correlated to real positions in the experimental room. However, correlation between spatial arrangements in the MDS-derived and real spaces was significantly smaller in virtual than real translocation tasks. The present results strongly suggest that the ensemble of the HF and PH neurons represent spatial information, and might provide a neurophysiological basis of the cognitive map. Less
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