Experimental study on the changes and regeneration of the cupula due to ototoxic drugs.

本文研究了机械振动对牛蛙和哺乳动物半规管顶端物理性质变化的影响。耳锥移入半规管管腔。这种情况被认为是BPPV胆管结石的模型。当耳石附着在杯状表面时，即为杯状结石模型。两种模型均能抑制正弦旋转刺激引起的神经活动。这被认为是BPPV患者热量反应和VOR降低的一个机制。将庆大霉素注入牛蛙内耳，观察牛蛙内耳顶盖的变化。盖子被缩小到大约一半大小。然而，顶盖表面的粘性保持不变。顶盖体积的减小使头部改变时容易偏转，从而可能导致位置性眩晕的发生。壶盖体积的减少也允许内淋巴通过壶腹壁逃逸，从而可能导致根管封堵术后的眩晕。

The effects of the changes in physical property of the semicircular canal cupula were studied Mechanical vibration to the middle ear induced detachment of the utricular otoconia both in bull frogs and mammals. The otoconia moved into semicircular canal lumen. This condition was regarded as a model of canalolithiasis of BPPV. When the otoconia were attached to the cupula surface, this was cupulolithiasis model. Both models suppressed the canal nerve activity induced by sinusoidal rotatory stimulus. This is considered to be a mechanism of decreased caloric response and VOR in BPPV patients. Gentamicin was injected into bullfrogs' inner ear and changes of the cupula were studied. The cupula was shrunken into about half size. However, the viscous nature of the cupula surface was maintained. Decreased cupula volume allows easy deflection upon head change, thus possibly leading to the occurrence of positional vertigo. Decreased cupula volume also allows the endolymph escape through ampullary wall, thus possibly leading to vertigo after canal plugging procedure.