Hummel Jennifer, Wolf Konstantin, Kössl Manfred, Nowotny Manuela
Institute of Cell Biology and Neuroscience, Goethe University, Max-von-Laue-Straße 13, 60438 Frankfurt am Main, Germany.
Institute of Cell Biology and Neuroscience, Goethe University, Max-von-Laue-Straße 13, 60438 Frankfurt am Main, Germany
Proc Biol Sci. 2014 Dec 7;281(1796):20141872. doi: 10.1098/rspb.2014.1872.
Processing of complex signals in the hearing organ remains poorly understood. This paper aims to contribute to this topic by presenting investigations on the mechanical and neuronal response of the hearing organ of the tropical bushcricket species Mecopoda elongata to simple pure tone signals as well as to the conspecific song as a complex acoustic signal. The high-frequency hearing organ of bushcrickets, the crista acustica (CA), is tonotopically tuned to frequencies between about 4 and 70 kHz. Laser Doppler vibrometer measurements revealed a strong and dominant low-frequency-induced motion of the CA when stimulated with either pure tone or complex stimuli. Consequently, the high-frequency distal area of the CA is more strongly deflected by low-frequency-induced waves than by high-frequency-induced waves. This low-frequency dominance will have strong effects on the processing of complex signals. Therefore, we additionally studied the neuronal response of the CA to native and frequency-manipulated chirps. Again, we found a dominant influence of low-frequency components within the conspecific song, indicating that the mechanical vibration pattern highly determines the neuronal response of the sensory cells. Thus, we conclude that the encoding of communication signals is modulated by ear mechanics.
听觉器官中复杂信号的处理仍未得到充分理解。本文旨在通过展示对热带灌丛蟋蟀长扁菱蝗听觉器官对简单纯音信号以及作为复杂声学信号的同种鸣声的机械和神经反应的研究，为这一主题做出贡献。灌丛蟋蟀的高频听觉器官，即听脊（CA），在约4至70千赫的频率范围内进行了音频定位调谐。激光多普勒振动计测量显示，当用纯音或复杂刺激进行刺激时，CA会出现强烈且占主导地位的低频诱导运动。因此，CA的高频远端区域被低频诱导波偏转的程度比被高频诱导波偏转的程度更大。这种低频主导将对复杂信号的处理产生强烈影响。因此，我们还研究了CA对原始和频率操纵的啁啾声的神经反应。同样，我们发现同种鸣声中的低频成分具有主导影响，这表明机械振动模式高度决定了感觉细胞的神经反应。因此，我们得出结论，通讯信号的编码受耳力学调制。
