Neural dynamics and memory consolidation in prefrontal cortex

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K07715
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 51010:Basic brain sciences-related
• Research Institution: Kansai Medical University
• Principal Investigator: HAYASHI Yuichiro 関西医科大学, 医学部, 博士研究員 (90378737)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 前頭前皮質 / カルシウムイメージング / 学習

Outline of Final Research Achievements

Rodents can distinguish between spatial environments and associate them with other behaviorally relevant information. In the hippocampus, a subpopulation of neurons that are active only in a specific spatial environment have been found, and they are likely involved in memory linked to the environment. Because the memory initially formed in the hippocampus is consolidated and stored long-term in neocortex, how spatial information is encoded in neocortex is an intriguing question. To address this, the activity of mouse mPFC in four different environments was recorded. In contrast to the CA1, the majority of mPFC neurons were inactive (45%) or active in all four environments (52%), and neurons active in 1-3 environments were rare (3%). Long-term tracking of mPFC activity revealed that the number of environments in which a cell showed activity was not preserved over time. These results suggest that the context representation in the mPFC is completely different from that in the hippocampus.

Free Research Field

神経生理学

Academic Significance and Societal Importance of the Research Achievements

人間を含む多くの動物には空間を認識する能力があり、様々な感覚と記憶を頼りに自分がどんな空間のどこに居るかを知ることができる。この能力が損なわれると社会生活に著しい不都合が生じる。海馬には空間内の場所特異的に活動するニューロンが存在し、場所感覚の基盤をなしていると考えられているが、空間を識別し自分の位置を知る脳内機構は現在も良くわかっていない。一方、大脳皮質にも空間特異的に活動するニューロンが見つかっており、脳の空間認識機構についてより幅広く調べるため、本研究では海馬と大脳皮質の場所表現の違いについて研究した。