豚鼠耳蜗局部微循环障碍的听力损伤特点

Characteristics of hearing loss caused by local microcirculatory disorders in cochlea of guinea pigs

目的 研究豚鼠耳蜗底回接近末端和耳蜗顶部区域局部微循环障碍的听力损伤特点。方法 光化学法在豚鼠耳蜗底回接近末端 1/ 2段或耳蜗区域分别诱导局部微循环障碍 ;常规火棉胶切片观察耳蜗形态学变化 ;Madsen2 2 5 0诱发电位系统记录各频率CAPN1。结果 当耳蜗底回接近末端发生局部微循环障碍时 ,听力损伤以高频最明显 ,同时伴有不同程度的低频听力损失。当耳蜗顶部区域发生局部微循环障碍时 ,听力损害以低频为主 ,同时也伴有不同程度的高频听力损失。

Objective To study the characteristics of hearing loss caused by local microcirculatory disorders in the cochlea of guinea pigs. Methods The local microcirculatory disorders in the cochlea basal turn near terminal or in the cupule of cochlea of guinea pigs were induced by photochemical reaction. The morphological changes in the cochlea were observed with light microscopy. The compound action potential N1 (CAPN 1) amplitude, latency, threshold shift evoked by short tone burst were recorded by Madsen 2250 system. Results When the local microcirculatory disorders took place in the cochlea basal turn near terminal, the hearing losses were more remarkable in the high-range frequencies, but with low-range ones to some extent. If the local microcirculatory disorders was induced in the cochlea cupule, the hearing losses were mainly in the low-range frequencies companying with some high-frequency ones. Conclusion Local microcirculatory disorders in the different parts of the cochlea cause different types of hearing loss in different frequency.