| Project/Area Number |
16300150
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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 |
Biomedical engineering/Biological material science
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| Research Institution | The University of Tokyo |
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Principal Investigator |
JIMBO Yasuhiko The University of Tokyo, Graduate School of Frontier Sciences, Professor, 大学院・新領域創成科学研究科, 教授 (20372401)
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| Co-Investigator(Kenkyū-buntansha) |
YASUDA Kenji Tokyo Medical and Dental University, Institute of Biomaterials and Bioengineering, Professor, 生体材料工学研究所, 教授 (20313158)
SAKUMA Ichiro The University of Tokyo, Graduate School of Engineering, Professor, 大学院・工学系研究科, 教授 (50178597)
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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 |
¥15,100,000 (Direct Cost: ¥15,100,000)
Fiscal Year 2006: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 2005: ¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2004: ¥9,500,000 (Direct Cost: ¥9,500,000)
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| Keywords | plasticity / cell culture / neuron / electrode array / electrical stimulation / neuronal network |
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| Research Abstract |
Activity-dependent modification of synaptic connections probably plays a key role in both proper network formation during development and learning and memory. Based on the capability of multi-site stimulation, MEA recording was applied to see modification of evoked responses induced by repetitive application of temporally correlated stimuli. Cortical neurons show developmental changes in spontaneous activity and reach the steady state after about one month in vitro. Evoked responses also depend on their developmental stages. Thus, in this work, matured cultures of more than 40 days in vitro were used for recording. A series of recording consists of (1) evoked responses to test stimuli and (2) responses to the correlated stimuli. The test stimuli were composed of 100 times of single pulse stimulus from site A and another 100 times from site B. Each single-site stimulation was applied every six seconds. The correlated stimuli consisted of 100 times of double pulses. The first pulse applied from site A was followed by the second pulse from the site B with a fixed time delay. Time delays of 100, 50, 20, 10, and 0 ms were tested. The total process of the experiment was composed of 6 sets of test stimuli and 5 sets of correlated stimuli: test1-A＆B100-test2-A＆B50-test3-A＆B20-test4-A＆B10-tests-A＆B0-test6. The evoked activity consisted of early and late components. At the initial state, almost no late components were recorded. After the correlated stimuli, strong late components appeared. The late components were detected after about 30 ms, and 20 ms, respectively. To analyze relationship between induced activity-changes and the applied correlated stimuli, cross-correlation functions were calculated. These results suggested that the properties of the applied correlated stimuli might be reflected in the spatio-temporal structures in the evoked responses.
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