Patuzzi R, Rajan R
Department of Physiology, University of Western Australia, Nedlands.
Hear Res. 1990 Apr;45(1-2):15-32. doi: 10.1016/0378-5955(90)90179-s.
Low-frequency microphonic waveforms have been recorded in the basal turn of the guinea pig cochlea with and without electrical stimulation of the crossed olivocochlear bundle (COCB) at the floor of the fourth ventricle. Stimulation of the COCB increased the amplitude of the microphonic waveforms as described previously, but did not alter the shape of the waveforms markedly. The changes observed with COCB stimulation are consistent with a reduction in the impedance of the basolateral wall of the outer hair cells by about 50%, and possibly a 20% increase in the vibration of the organ of Corti at low frequencies, but suggest little or no change in the operating point on the transfer curve relating deflection of the hair bundles to the receptor current through the hair cells. It therefore seems that if slow contraction of the outer hair cells occurs during acute efferent stimulation in vivo, then it produces only a small deflection of the outer hair cell stereocilia, equivalent to a transverse displacement of the organ of Corti of less than 1.5 nm.
在豚鼠耳蜗基底转，记录了有无对第四脑室底部的交叉橄榄耳蜗束（COCB）进行电刺激时的低频微音器波形。如先前所述，刺激COCB会增加微音器波形的幅度，但并未显著改变波形的形状。COCB刺激所观察到的变化与外毛细胞基底外侧壁的阻抗降低约50%一致，并且可能低频时柯蒂氏器的振动增加20%，但表明在将毛束偏转与通过毛细胞的受体电流相关的传递曲线上，工作点几乎没有变化。因此，似乎如果在体内急性传出刺激期间外毛细胞发生缓慢收缩，那么它只会使外毛细胞静纤毛产生小的偏转，相当于柯蒂氏器横向位移小于1.5纳米。
