Mapping working memory networks in the Drosophila brain

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K06496
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 46010:Neuroscience-general-related
• Research Institution: Tokyo Metropolitan Institute of Medical Science
• Principal Investigator: HORIUCHI Junjiro 公益財団法人東京都医学総合研究所, 脳・神経科学研究分野, 主席研究員 (80392364)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: Drosophila / forgetting / aging / learning and memory

Outline of Final Research Achievements

We characterized forgetting in Drosophila using behavioral and mathematical methods and found that a major component of forgetting is an increase in uncertainty regarding a memory. This increase results in a reduction in the ability of a memory to influence memory-related behaviors. To understand the cellular basis of forgetting and memory uncertainty, we examined memory engram cells in young and old flies. Compared to young flies, old flies have increased forgetting and reduced memory scores. We found that both young and old flies produce similar numbers of engram cells after training. Cues that activate memory recall induce reactivation of engram cells in both young and old flies. However, unrelated cues activate engram cells in old, but not young flies. Thus, a major component of age-dependent forgetting is memory generalization where memories are activated by inappropriate stimuli. We identified the cells and neurotransmitters responsible for memory generalization.

Free Research Field

Drosophila neurobiology

Academic Significance and Societal Importance of the Research Achievements

私たちの性格は経験と記憶で形成される。現在、社会を悩ませている病気の中で自分の性格を失う認知症は特に恐ろしい。認知症で何が起こるかを理解するには、物忘れが脳内でどのように起こるかを理解する必要がある。忘れることは単なる記憶の喪失か？ それとも、記憶に関する不確実が段階的に増大する現象か？私たちの研究では記憶の不確実性が高まることが忘れの原因だということを明らかにした。さらに、記憶の不確実性を引き起こす細胞および分子の変化を特定した。 これらの発見は、物忘れを理解することに役立ち、さらに高齢者の物忘れを改善するための新しい戦略の開発に役立つことが期待される。