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01 奈良県立医科大学 >
012 大学院 >
0122 学位請求論文 >
01221 博士論文(医学) >
2024年度 >
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http://hdl.handle.net/10564/4460
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タイトル: | Effects of aging on otolith morphology and functions in mice |
その他のタイトル: | 加齢がマウスの耳石器の形態と機能に与える影響について |
著者: | Ueda, Keita Imai, Takao Ito, Taeko Okayasu, Tadao Harada, Shotaro Kamakura, Takefumi Ono, Kazuya Katsuno, Tatsuya Tanaka, Tatsuhide Tatsumi, Kouko Hibino, Hiroshi Wanaka, Akio Kitahara, Tadashi |
キーワード: | otolith otoconia micro-computed tomography linear vestibulo-ocular reflex mice |
発行日: | 2024年10月 |
出版者: | Frontiers Media S.A. |
引用: | Frontiers in neuroscience. 2024 Oct, vol.18, article no.1466514 |
抄録: | Background: Increased fall risk caused by vestibular system impairment is a significant problem associated with aging. A vestibule is composed of linear acceleration-sensing otoliths and rotation-sensing semicircular canals. Otoliths, composed of utricle and saccule, detect linear accelerations. Otolithic organs partially play a role in falls due to aging. Aging possibly changes the morphology
and functions of otoliths. However, the specific associations between aging and otolith changes remain unknown. Therefore, this study aimed to clarify these associations in mice.
Methods: Young C56BL/6 N (8 week old) and old (108–117 weeks old) mice were used in a micro-computed tomography (μCT) experiment for morphological analysis and a linear acceleration experiment for functional analysis. Young C56BL/6 N (8 week old) and middle-aged (50 week old) mice were used in
electron microscopy experiments for morphological analysis.
Results: μCT revealed no significant differences in the otolith volume (p = 0.11)
but significant differences in the otolith density (p = 0.001) between young and old mice. μCT and electron microscopy revealed significant differences
in the structure of striola at the center of the otolith (μCT; p = 0.029, electron
microscopy; p = 0.017). Significant differences were also observed in the
amplitude of the eye movement during the vestibulo-ocular reflex induced
by linear acceleration (maximum amplitude of stimulation = 1.3G [p = 0.014];
maximum amplitude of stimulation = 0.7G [p = 0.015]), indicating that the otolith
function was worse in old mice than in young mice.
Discussion: This study demonstrated the decline in otolith function with age
caused by age-related morphological changes. Specifically, when otolith
density decreased, inertial force acting on the hair cells decreased, and when the
structure of striola collapsed, the function of cross-striolar inhibition decreased,
thereby causing a decline in the overall otolith function. |
内容記述: | 権利情報:© 2024 Ueda, Imai, Ito, Okayasu, Harada,
Kamakura, Ono, Katsuno, Tanaka, Tatsumi,
Hibino, Wanaka and Kitahara. This is an
open-access article distributed under the
terms of the Creative Commons Attribution
License (CC BY). The use, distribution or
reproduction in other forums is permitted,
provided the original author(s) and the
copyright owner(s) are credited and that the
original publication in this journal is cited, in accordance with accepted academic
practice. No use, distribution or reproduction
is permitted which does not comply with
these terms. |
URI: | http://hdl.handle.net/10564/4460 |
ISSN: | 1662-453X |
DOI: | https://doi.org/10.3389/fnins.2024.1466514 |
学位授与番号: | 24601甲第965号 |
学位授与年月日: | 2025-03-14 |
学位名: | 博士(医学) |
学位授与機関: | 奈良県立医科大学 |
出現コレクション: | 2024年度
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