Müller Marcus, Smolders Jean W T
Physiology II, J.W. Goethe-University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany.
Neuroreport. 2005 Aug 1;16(11):1183-7. doi: 10.1097/00001756-200508010-00010.
The cochlear place-frequency map, determined from noise-damaged mice, is shifted to lower frequencies by up to one octave compared with the map determined from normal hearing mice. To test the hypothesis that the shift results from damage to the cochlear amplifier, we measured frequency tuning curves from the same neurons before and after noise exposure. Noise damage resulted in loss of tuning and elevation of thresholds. The neuronal characteristic frequency shifted by 0.6-1.2 octaves, dependent on frequency. The shift in characteristic frequency was used to calculate a shifted place-frequency map. We conclude that desensitization of areas in the inner ear after noise exposure can explain the shift of the map after noise damage relative to the normal physiological map.
与正常听力小鼠所确定的耳蜗部位-频率图相比，由噪声损伤小鼠所确定的耳蜗部位-频率图向低频方向移动了多达一个八度。为了验证这种移位是由耳蜗放大器受损所致的假设，我们在噪声暴露前后测量了同一神经元的频率调谐曲线。噪声损伤导致调谐丧失和阈值升高。神经元的特征频率根据频率不同而移位了0.6 - 1.2个八度。特征频率的移位被用于计算一个移位后的部位-频率图。我们得出结论，噪声暴露后内耳区域的脱敏可以解释噪声损伤后该图谱相对于正常生理图谱的移位。
