外毛细胞能动性介导耳蜗放大器机制的在体实验研究

The human auditory sensory organ, the cochlea, has exceptional sensitivity and enormous dynamic range.The cochlear amplifier is a mechanism within the cochlea that provides acute sensitivity in the mammalian auditory system,the main component of the cochlear amplifier is the outer hair cell (OHC) .It is commonly believed that the cochlea achieves its extraordinary sensitivity through the cochlear amplifier region which is predicted to operate before the traveling wave reaches the character frequency. So far, it is still unknown how the OHCs within the cochlear amplifier region amplify the vibration of BM in vivo. Our previous experiments show that there is a distorted vibration of organ of Corti induced by the low level sound stimulation, and the length and phase change of OHCs is the reason of the distorted vibration of organ of Corti. To deeply study how the length and phase change of OHCs within the cochlear amplifier region contribute to the amplification of the vibration of BM in vivo and further probe the mechanism of cochlear amplifier, in this project, using Optical Coherence Tomograph (OCT) and Cochlear microperfusion, we will confirm the cochlear amplifier region and we will study how the length and phase change of OHCs within the cochlear amplifier region contribute to the amplification of BM vibration in vivo. The purpose of this project is to provide in vivo experimental data for elucidating the mechanism of cochlear amplifier.

人耳听觉有着极精细的分辨力和极宽广的动态范围，耳蜗外毛细胞（OHC）能动性为核心的"耳蜗放大器"是这种精细调控的基础。耳蜗基底膜特征频率附近沿基底膜纵向存在一个"放大器区间"参与放大基底膜振动，但迄今为止，放大器区间内OHC如何调控放大基底膜振动并参与耳蜗放大器机制尚缺乏在体研究。我们的前期研究发现耳蜗Corti器在低强度声刺激时存在明显的振动畸变，进一步的研究发现在体OHC自身长度和特征性的相位变化是引起Corti器振动畸变的主要原因。为深入研究在体OHC长度和相位变化是如何调控声刺激诱发的基底膜振动并进一步揭示耳蜗放大器机制，本课题中我们将运用OCT在体记录技术和耳蜗微灌注技术，在听力敏感豚鼠模型上在体确认耳蜗放大器区间，深入研究耳蜗放大器区间内OHC能动性介导的OHC长度和相位变化特征及其与基底膜放大调谐振动的关系，本研究将为耳蜗放大器理论提供在体实验依据，并深入阐明耳蜗放大器机制。

人耳听觉有着极精细的分辨力和极宽广的动态范围，耳蜗外毛细胞（OHC）能动性为核心的“耳蜗放大器”是这种精细调控的基础。耳蜗基底膜特征频率附近沿基底膜纵向存在一个“放大器区间”参与放大基底膜振动。我们的前期研究发现耳蜗Corti器在低强度声刺激时存在明显的振动畸变，进一步的研究发现在体OHC自身长度和特征性的相位变化是引起Corti器振动畸变的主要原因。为深入研究在体OHC长度和相位变化是如何调控声刺激诱发的基底膜振动并进一步揭示耳蜗放大器机制，本课题中我们运用OCT在体记录技术和耳蜗微灌注技术，在听力敏感豚鼠模型上在体确认耳蜗放大器区间，深入研究了耳蜗放大器区间内OHC能动性介导的OHC长度和相位变化特征及其与基底膜放大调谐振动的关系，本研究为耳蜗放大器理论提供了在体实验依据。