2022 Fiscal Year Research-status Report
3D spatial coding in the monkey hippocampus
| Project/Area Number |
22K07320
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| Research Institution | University of Toyama |
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Principal Investigator |
YOUNG MEGAN 富山大学, 学術研究部医学系, 特命助教 (50930830)
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| Co-Investigator(Kenkyū-buntansha) |
田村 了以 富山大学, 学術研究部医学系, 教授 (60227296)
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| Project Period (FY) |
2022-04-01 – 2025-03-31
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| Keywords | hippocampus / primate / electrophysiology |
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| Outline of Annual Research Achievements |
Since the discovery of hippocampal place cells by O'Keefe, there have been many studies on the neural basis of spatial cognition in the rodent hippocampus, but knowledge on primate hippocampal place cells is limited. The purpose of this study was to record neuronal activity from the hippocampus of monkeys moving in a 3D environment, and to clarify the relationship between the animal's direction of movement (horizontal and vertical) and place responsiveness. Conventional recording of neuronal activity via signal transmission cables is problematic because it interferes with the movement of monkeys in a 3D environment with complex structures. Previously we trained the monkeys in a 3D environment consisting of horizontal and vertical moving spaces connected in an L-shape, and found the movement of the monkey was restricted at the L-shaped ends, which could make it difficult to analyze neuronal activity. Therefore, this fiscal year we completed a square doughnut-shaped 3D environment. In this fiscal year, we first and trained a rhesus monkey to move in clockwise and counter-clockwise directions in this 3D environment. We also developed an AI-based monkey behavior monitoring system capable of identifying the monkey's position and pose. Then, a cranioplastic head cap was surgically attached to the head of the monkey; evoked potential mapping is currently being conducted to accurately estimate the optimal location for recording neuronal activity.
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| Current Status of Research Progress |
Current Status of Research Progress
1: Research has progressed more than it was originally planned.
Reason
The research is progressing smoothly. The 3D environment and camera system have been constructed. The monkey has been implanted successfully with the recording chamber, and mapping is progressing to localize the target recording area.
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| Strategy for Future Research Activity |
The next steps taken will be to finish mapping and implant chronic electrodes, and to begin to record neuronal data from the monkey hippocampus using the wireless recording system as the animal traverses the 3D environment, while recording video for processing with the position tracking system.
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| Causes of Carryover |
Remaining funds will be used for supplies as needed for recording and animal maintenance, for hardware for analysis of recorded video as well as neuronal data, and for fees for travel and conference fees to present research findings.
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