Mechanics of brain development: elasticity, residual tissue stress, and mechanosensing

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H02656
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 48010:Anatomy-related
• Research Institution: Nagoya University
• Principal Investigator: Miyata Takaki 名古屋大学, 医学系研究科, 教授 (70311751)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 脳発生 / 力学的要因 / 弾性 / 圧縮 / 張力 / 応力解放試験 / アクトミオシン / 神経前駆細胞

Outline of Final Research Achievements

When circumferential continuity of the midembryonic cerbral wall was reduced to a degree to leave only a cube-like structure, such cubes observed in culture medium spontaneously changed their overall shapes in 30~60 min, showing the bulging of the neuronal zones to the lateral direction, which was coupled with the thinning of the entire wall. These results indicate that pressure-relieving recoil of the intramural neurons lateral to and beyond the slice edges upon surgery always resulted in thinning of the neuronal layers and shortening of neural progenitor cells along the apicobasal axis. It is therefore suggested that in vivo neurons, packed in a manner compressed centripetally parallel to the wall surfaces (along the circumferential plane including the anterior-posterior and dorsoventral axes), use their counteractingly expansive property to orthogonally (thus apicobasally) stratify themselves to thicken the wall. The wall is therefore under self-tightening for mechanical stability.

Free Research Field

発生学，解剖学，神経科学

Academic Significance and Societal Importance of the Research Achievements

建築物・工業製品であれ地球上構造であれ，何かが生じる・作られる場合に「ちから」は 必ず意識され，力学的に「どうある」かの理解が「カタチ」の成立を説明する．しかし「哺乳類の脳づくり」は，どんな形態成立原理の探求にも本来欠かせないはずの力学的な視点と，それに沿った解析法をほとんど持たないままであった．本研究がもたらした，胎生期の脳原基における力学的な理解，すなわち，どんな細胞がどの向きのどんな力を受け取るか，は，将来的に「mechanopathy メカノパシー」と括られることになる可能性のある分子病態の理解のための細胞・組織力学の基盤となり得ると予想され，重要である．