Organ of corti potentials and the motion of the basilar membrane
Organ of corti potentials and the motion of the basilar membrane
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DOI：
10.1523/jneurosci.2711-04.2004
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发表时间：
2004-11-10
影响因子：
5.3
通讯作者：
Nuttall, A
中科院分区：
文献类型：
--
作者：
Fridberger, A;de Monvel, JB;Nuttall, A
在声音刺激期间，在耳蜗的感觉毛细胞内产生受体电位。流行的理论认为，外毛细胞使用电位敏感的运动蛋白普雷斯廷将受体电位转化为细胞长度或硬度的快速变化，从而使听力灵敏度提高近1000倍。然而，受体电位被细胞膜的电容和电阻形成的滤波器衰减。这种衰减将限制高刺激频率下的细胞运动性，使上述方案无效。因此，Dallos和Evans（1995 a）提出Corti器内的细胞外电位变化可以驱动细胞运动蛋白。这些细胞外电位不被膜过滤。为了验证这一理论，测量了Corti器官内的电位和基底膜振动对声学刺激的反应。振动测量的网站非常接近那些询问的记录电极使用激光干涉。通过比较所测得的电调谐曲线和机械调谐曲线以及时间波形和它们的相位关系，发现这些细胞外电位确实可以驱动外毛细胞马达。然而，为了实现基底膜特有的尖锐频率调谐，必须在Corti器官内进行额外的机械处理。
During sound stimulation, receptor potentials are generated within the sensory hair cells of the cochlea. Prevailing theory states that outer hair cells use the potential-sensitive motor protein prestin to convert receptor potentials into fast alterations of cellular length or stiffness that boost hearing sensitivity almost 1000-fold. However, receptor potentials are attenuated by the filter formed by the capacitance and resistance of the membrane of the cell. This attenuation would limit cellular motility at high stimulus frequencies, rendering the above scheme ineffective. Therefore, Dallos and Evans ( 1995a) proposed that extracellular potential changes within the organ of Corti could drive cellular motor proteins. These extracellular potentials are not filtered by the membrane. To test this theory, both electric potentials inside the organ of Corti and basilar membrane vibration were measured in response to acoustic stimulation. Vibrations were measured at sites very close to those interrogated by the recording electrode using laser interferometry. Close comparison of the measured electrical and mechanical tuning curves and time waveforms and their phase relationships revealed that those extracellular potentials indeed could drive outer hair cell motors. However, to achieve the sharp frequency tuning that characterizes the basilar membrane, additional mechanical processing must occur inside the organ of Corti.