Investigation of Early Structural Changes in Outer Hair Cell Damage Using Focused Ion Beam Scanning Electron Microscopy

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K16857
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 56050:Otorhinolaryngology-related
• Research Institution: Juntendo University
• Principal Investigator: Anzai Takashi 順天堂大学, 医学部, 准教授 (20624852)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: 内耳 / 収束イオンビーム搭載操作顕微鏡 / FIB/SEM / 外有毛細胞

Outline of Final Research Achievements

We created thin horizontal slices of the cochlear sensory epithelium in the mouse inner ear and obtained sequential images of outer hair cells, which are important cells for sensing sound, using a focused ion beam-equipped scanning microscope.
We were able to observe a cyst-like subcellular structure called subsurface cisternae, located just beneath the cell membrane of the outer hair cells, which is considered vital for cellular energy supply. Furthermore, by digitally tracing and reconstructing these sequential images, we were able to capture the three-dimensional structure of the intracellular organelles of the outer hair cells, which were previously observed only in planar structures.

Free Research Field

分子細胞生物学

Academic Significance and Societal Importance of the Research Achievements

収束イオンビーム搭載操作顕微鏡で撮影した連続画像のsubsurface cisternae及び細胞膜をデジタルトレースを行うことでこれまで平面でとらえられていた構造を立体構造として可視化し得た。Subsurface cisternaeはATP産生の場としても注目されており、疾患モデルとの比較により障害の程度を定量化する新たな指標になりえることが期待できる。