研究課題/領域番号 |
21K06419
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研究種目 |
基盤研究(C)
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配分区分 | 基金 |
応募区分 | 一般 |
審査区分 |
小区分46030:神経機能学関連
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研究機関 | 筑波大学 |
研究代表者 |
Kumar Deependra 筑波大学, 国際統合睡眠医科学研究機構, 研究員 (20747696)
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研究分担者 |
船戸 弘正 筑波大学, 国際統合睡眠医科学研究機構, 客員教授 (90363118)
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研究期間 (年度) |
2021-04-01 – 2024-03-31
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研究課題ステータス |
交付 (2022年度)
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配分額 *注記 |
4,030千円 (直接経費: 3,100千円、間接経費: 930千円)
2023年度: 650千円 (直接経費: 500千円、間接経費: 150千円)
2022年度: 520千円 (直接経費: 400千円、間接経費: 120千円)
2021年度: 2,860千円 (直接経費: 2,200千円、間接経費: 660千円)
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キーワード | Sleep / memory / Theta / hippocampus / neonates / TRAP2 / Dreamless / Fear expression / Neonatal sleep / Neonatal memory / Theta rhythm maturation / Dreamless mice / Engram |
研究開始時の研究の概要 |
During the development, a low amplitude theta wave starts appearing from postnatal day 16 (P16) and reaches its maturity on P26. However, the critical period when theta activity associated with REM sleep to consolidate memory is unknown. Therefore, this study aims to determine the normal development of REM theta-dependent memory consolidation mechanism during the neonatal stage.
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研究実績の概要 |
We found dreamless mice display low freezing behavior during fear conditioning, which could be due to chronic loss of REM sleep. Early data indicates their REM sleep duration gets further shortened during the postconditioning sleep, which can influence the memory consolidation. Furthermore, hippocampal theta shows low spectral power during REM sleep, that required for memory storage.
Indeed dreamless show low-freezing behavior one day or two weeks later. Dreamless shows a larger loss of memory at two weeks time, indicating faster memory decay compared with wild type littermates . Upon remote memory retrieval, the number of c-fos positive cells in the anterior cingulate cortex (ACC), a center for remote memory storage, was low in dreamless, which agrees with lower freezing behavior.
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現在までの達成度 (区分) |
現在までの達成度 (区分)
1: 当初の計画以上に進展している
理由
Customized tetrode required to measure LFP in the neonatal brain is established.
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今後の研究の推進方策 |
In mutant mice, LFP will be measured simultaneously from the medial septum (theta generator) and hippocampus (prominent theta in REM) to narrow the region and cause-related with low theta in mutant mice. Theta synchronicity between the hippocampus, amygdala, and medial prefrontal cortex is essential for memory task performance. LFP will be measured during fear learning, sleep, and memory retrieval period. Can theta wave enhancement rescue fear memory in mutant mice? To test, dreamless mutants expressing channelrhodopsin in medial septum cholinergic neurons will receive laser light to induce hippocampal theta during task performance and sleep artificially. How does theta enhancement affect the activity of learning tag cells? Imaging and optogenetics techniques will be combined to understand theta's role in the consolidation mechanism.
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