A comprehensive odor mapping of compartmentalized and valence-encoding MB intrinsic neurons in Drosophila

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K16254
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 46010:Neuroscience-general-related
• Research Institution: The University of Tokyo
• Principal Investigator: Abe Takashi 東京大学, 定量生命科学研究所, 助教 (70756824)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 2光子顕微鏡カルシウムイメージング / 嗅覚記憶連合学習 / ショウジョウバエ キノコ体 / cAMP / Calucium / Dopamine / ACh / PKA

Outline of Final Research Achievements

The Drosophila mushroom body (MB) is the site of memory formation through the association of olfactory stimuli with aversive/attractive stimuli. The MB neurons consist of functionally distinct subtypes, and each axonal bundle is compartmentalized into multiple output regions, receiving distinct regulation. Using two-photon microscopy, we conducted experiments to obtain basic response profiles through in vivo imaging of odor responses in axonal regions before associative conditoning, aiming to establish a foundation for presynaptic plasticity analysis.
Subsequently, we introduced a highly sensitive sensor for cAMP, which is thought to act as a coincidence detector in associative learning, and conducted simultaneous imaging of calcium and cAMP during association.
This led to the observation of phenomena that could not be explained by the classical associative model. After further detailed experiments and analysis, we proposed a new model and submitted a paper on this to bioRxiv

Free Research Field

神経生物学

Academic Significance and Societal Importance of the Research Achievements

キノコ体のポストシナプス側であるMBON神経においては、網羅的に単一神経レベルの解像度で匂い応答が調べられ、可塑的変化も顕微鏡下で示された。一方プレシナプス側であるKCsにも可視的に検出可能な可塑性があるのかどうかは未解明の部分が多かった。これには、それぞれのKCサブタイプの区画化された出力域においてどのような制御機構が存在するのかについて多くが未知であり、可塑性変化の検出の前提となる生理学的知見が不足していることが一因として考えられた。サブタイプを分離した発現系統を用いることで、可視的に、時空間的分解能が高い応答プロファイルの構築が可能となり匂い記憶の形成メカニズムの理解に近づけると考えた。