Cheatham M A, Dallos P
Hugh Knowles Center, Northwestern University, Evanston, Illinois 60208-3550, USA.
J Acoust Soc Am. 1998 Jul;104(1):356-69. doi: 10.1121/1.423245.
Hair cell responses are recorded from third turn of the guinea pig cochlea in order to define the relationship between hair cell depolarization and position of the basilar membrane. Because the latter is determined locally, using the cochlear microphonic recorded in the organ of Corti (OC) fluid space, no corrections are required to compensate traveling wave and/or synaptic delays. At low levels, inner hair cells (IHC) depolarize near basilar membrane velocity to scala vestibuli reflecting the free standing nature of their stereocilia. At high levels, the time of depolarization changes rapidly from velocity to scala vestibuli to the scala tympani phase of the basilar membrane response. This change in response phase, recorded in the fundamental component of the IHC response, is associated with a decrease in response magnitude. The absence of this behavior in OC and outer hair cell responses implies that basilar membrane mechanics may not be responsible for these response patterns. Because these features are reminiscent of the magnitude notches and the large phase shifts observed in single unit responses at high stimulus levels, they provide the IHC correlates of these phenomena.
从豚鼠耳蜗第三转记录毛细胞反应，以确定毛细胞去极化与基底膜位置之间的关系。由于后者是局部确定的，利用在柯蒂氏器（OC）液腔中记录的耳蜗微音器电位，无需进行校正来补偿行波和/或突触延迟。在低强度时，内毛细胞（IHC）在基底膜向前庭阶的速度附近去极化，反映了其静纤毛的自由站立性质。在高强度时，去极化时间从基底膜向前庭阶的速度迅速变化到基底膜反应的鼓阶阶段。在IHC反应的基本成分中记录到的这种反应相位变化与反应幅度的降低有关。OC和外毛细胞反应中不存在这种行为，这意味着基底膜力学可能不是这些反应模式的原因。因为这些特征让人联想到在高刺激强度下单单位反应中观察到的幅度凹陷和大的相位偏移，它们提供了这些现象的IHC相关因素。
