Department of Otolaryngology, Head and Neck Surgery, Yamagata University Faculty of Medicine, Yamagata, Japan.
Department of Otolaryngology, Head and Neck Surgery, Yamagata University Faculty of Medicine, Yamagata, Japan.
J Neurosci Methods. 2021 Mar 1;351:109049. doi: 10.1016/j.jneumeth.2020.109049. Epub 2021 Jan 7.
Vestibular hair cell loss and its role in balance disorders are not yet completely understood due largely to the lack of precise hair cell damage protocols.
Our damage protocol aims to selectively remove type I hair cells in a way that produces consistent and predictable lesions that can be used for reliable inter-animal and inter-group comparison in balance research. This objective is achieved by transtympanic injection of gentamicin on both the round window membrane and oval window over a fixed time period followed by thorough washing.
We achieved nearly total and consistent loss of type I hair cells at 94 % for the crista ampullaris of the lateral semicircular canal (LSC) and 86 % for the utricular macula with negligible loss of type II hair cells at 4% for the crista ampullaris of the LSC and 6% for the utricular macula. While the vestibular function was compromised in the relevant study group, this group had a zero mortality rate with no significant suppression of body weight gain.
Gentamicin is typically administered via intraperitoneal systemic injection or, more recently, transtympanic injection. The intraperitoneal method is simple, but mortality rate is high. The transtympanic injection method produces ototoxic damage but with inconsistent lesion size. This inconsistency prevents reliable comparisons among animals.
This protocol employs a transtympanic injection method which selectively targets type I hair cells for removal in the vestibular epithelia in a time-dependent manner, uniformly damages vestibular function, and causes uniform hair cell loss.
由于缺乏精确的毛细胞损伤方案，前庭毛细胞损失及其在平衡障碍中的作用尚不完全清楚。
我们的损伤方案旨在以一种可产生一致且可预测损伤的方式选择性地去除 I 型毛细胞，从而可在平衡研究中用于可靠的动物间和组间比较。这一目标通过在固定时间内在圆窗膜和卵圆窗上对庆大霉素进行鼓室内注射，然后进行彻底冲洗来实现。
我们在外侧半规管壶腹嵴（LSC）的 94%和椭圆囊的 86%达到了几乎完全和一致的 I 型毛细胞损失，而 II 型毛细胞的损失可忽略不计，分别为 LSC 壶腹嵴的 4%和椭圆囊的 6%。虽然相关研究组的前庭功能受损，但该组的死亡率为零，体重增长无明显抑制。
庆大霉素通常通过腹腔内全身注射或最近通过鼓室内注射给药。腹腔内方法简单，但死亡率高。鼓室内注射法产生耳毒性损伤，但损伤大小不一致。这种不一致性阻止了动物之间的可靠比较。
该方案采用鼓室内注射方法，以时间依赖性方式选择性地去除前庭上皮中的 I 型毛细胞，均匀地损伤前庭功能，并导致均匀的毛细胞损失。
