Ulfendahl M, Khanna S M, Flock A
Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
Neuroscience. 1996 May;72(1):199-212. doi: 10.1016/0306-4522(95)00545-5.
The mechanical tuning characteristics of the hearing organ were measured in response to sound stimulation using laser heterodyne interferometry in in vitro preparations of temporal bones from waltzing guinea-pigs expressing different degrees of hearing organ and sensory cell degeneration. Measurements were made at various stages of structural changes allowing us to correlate structure and mechanical function. It was found that the characteristic frequency of the response at a given location in the cochlea occurred at lower frequencies than what is normally seen and that the sharpness of the mechanical tuning was considerably reduced when sensory hair cells were absent and the hearing organ structurally altered. However, even when extensive hair cell degeneration was evident a residual mechanical tuning was present. These results further support the concept that the sensory hair cells plays a key role in determining normal auditory tuning characteristics. It is suggested that the basilar membrane mechanics gives rise to a broadly tuned mechanical response on which a sharper tuning mechanism, originating from the hair cells, is superimposed.
利用激光外差干涉测量法，在表达不同程度听觉器官和感觉细胞退化的华尔兹豚鼠颞骨体外制备物中，测量了听觉器官对声音刺激的机械调谐特性。在结构变化的各个阶段进行测量，使我们能够将结构与机械功能联系起来。研究发现，耳蜗中给定位置的反应特征频率出现在比正常情况更低的频率，并且当感觉毛细胞缺失且听觉器官结构改变时，机械调谐的锐度会显著降低。然而，即使明显存在广泛的毛细胞退化，仍存在残余的机械调谐。这些结果进一步支持了感觉毛细胞在决定正常听觉调谐特性中起关键作用的概念。有人提出，基底膜力学产生了一种宽泛调谐的机械反应，在此基础上叠加了一种源自毛细胞的更尖锐的调谐机制。
