Lu Z, Xu Z
Department of Biology, University of Miami, Coral Gables, FL 33146-0421, USA.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2002 Sep;188(8):595-602. doi: 10.1007/s00359-002-0334-6. Epub 2002 Aug 15.
It is not known to what extent the entire saccule contributes to overall hearing sensitivity in any fish species. Here we report directional and frequency sensitivity in a teleost fish (Dormitator latifrons) and effects of unilateral and bilateral removal of saccular otoliths on its hearing sensitivity. The fish had different hearing thresholds in the horizontal (-54.4 to -50.3 dB re: 1 micro m) and mid-sagittal (-58.6 to -53.1 dB) planes. At 100 Hz, unilateral otolith removal did not significantly change hearing sensitivity in the mid-sagittal plane, but caused selective reductions of auditory sensitivity by 3-7 dB in the azimuthal axes that are consistent with the longitudinal axis of the damaged saccule. Along the fish's longitudinal axis, unilateral otolith removal significantly decreased auditory sensitivity at 50 Hz and 400 Hz, but not at 100 Hz, 200 Hz, and 345 Hz. At 100 Hz, bilateral otolith removal resulted in robust hearing loss of 27-35 dB at different axes in both horizontal and mid-sagittal planes. Along the fish's longitudinal axis, the bilateral removal reduced auditory sensitivity by 13-27 dB at the different frequencies. Therefore, these results demonstrate that the saccule plays important roles in directional hearing and frequency responses.
目前尚不清楚在任何鱼类中，整个球囊对总体听力敏感度的贡献程度如何。在此，我们报告了一种硬骨鱼（宽体眠鱼）的方向和频率敏感度，以及单侧和双侧去除球囊耳石对其听力敏感度的影响。该鱼在水平平面（相对于1微米为-54.4至-50.3分贝）和矢状中平面（-58.6至-53.1分贝）具有不同的听力阈值。在100赫兹时，单侧去除耳石在矢状中平面并未显著改变听力敏感度，但在与受损球囊纵轴一致的方位轴上导致听觉敏感度选择性降低3至7分贝。沿着鱼的纵轴，单侧去除耳石在50赫兹和400赫兹时显著降低了听觉敏感度，但在100赫兹、200赫兹和345赫兹时没有。在100赫兹时，双侧去除耳石导致在水平和矢状中平面的不同轴上出现27至35分贝的明显听力损失。沿着鱼的纵轴，双侧去除在不同频率下使听觉敏感度降低了13至27分贝。因此，这些结果表明球囊在定向听力和频率响应中发挥着重要作用。
