Reexamination of adult neurogenesis in the marmoset and human hippocampus

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K06930
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 46020:Anatomy and histopathology of nervous system-related
• Research Institution: Juntendo University (2021-2022); Tokyo Medical University (2019-2020)
• Principal Investigator: Seki Tatsunori 順天堂大学, 医学部, 非常勤講師 (20175417)
• Co-Investigator(Kenkyū-buntansha): 柏木 太一 東京医科大学, 医学部, 助教 (10398232) ; 篠原 広志 東京医科大学, 医学部, 講師 (10455793) ; 權田 裕子 東京医科大学, 医学部, 講師 (60424181)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 成体脳ニューロン新生 / 海馬 / ヒト / マーモセット / 未熟ニューロン / 可塑性

Outline of Final Research Achievements

Studies in rodents have demonstrated that adult neurogenesis occurs in the granule cell layer (GCL) of the hippocampus, and is involved in various hippocampal functions, such as memory and learning, and pathological conditions. However, it remains controversial as to what extent adult neurogenesis actually occurs in the adult human hippocampus. To address this question, we analyzed immature neuronal marker-positive (INM+) cells and proliferating neuronal progenitor cells in humans and marmosets. The present study shows that marmosets and humans harbor abundant INM+ cells not only in the GCL, but also in the hilus, unlike rodents. Although in marmosets, newly generated neurons were always detected in the GCL, but in humans, there were few proliferating neuronal progenitors. These results suggest that the INM+ cells in the adult human hippocampus are not newly generated neurons, and may compensate for the decline in plasticity by a low level of neurogenesis.

Free Research Field

神経発生学

Academic Significance and Societal Importance of the Research Achievements

本研究は、ヒトの海馬のニューロン新生は低いが、未熟な性質のニューロンは豊富に存在することを示している。この未熟な性質のニューロンは、海馬の可塑性（記憶・学習の基盤）や神経再生に関与している可能性があり、学術的にも社会的にも意義があると考えている。