A tympanal insect ear exploits a critical oscillator for active amplification and tuning.
A tympanal insect ear exploits a critical oscillator for active amplification and tuning.
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DOI：
10.1016/j.cub.2013.08.028
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发表时间：
2013-10-07
期刊：
影响因子：
--
通讯作者：
Robert D
中科院分区：
文献类型：
--
作者：
Mhatre N;Robert D
声学通信的一个主导主题是将声学空间划分为排他性的、物种特异性的小生境，以实现有效的信息传递。在昆虫中，声音生态位的划分是通过听觉频率过滤来实现的，这是由它们耳朵的机械特性引起的。然而，蚊子和苍蝇的触角耳朵的调谐来自主动放大，这一过程类似于哺乳动物耳蜗的工作过程。然而，在昆虫的另一种耳--鼓膜耳中是否存在主动放大仍然不确定。在这里，我们证明了存在的主动放大和自适应调谐在鼓膜的一个寄生虫的基础昆虫，树蟋蟀。我们还表明，树蟋蟀利用关键的搅拌机一样的机制，使高听觉灵敏度和调谐到同种歌曲。这些发现意味着，复杂的听觉机制可能出现在听觉和声学交流的进化过程中，甚至比目前所认识的更早。我们的研究结果还提出了一种可能性，即鼓室系统的频率辨别和定向听力可能依赖于生理非线性，除了机械性能，有效地解除了一些物理限制放在昆虫的小尺寸，并促使广泛的无脊椎动物的听力重新检查。树蟋蟀的鼓膜耳朵使用主动放大主动放大而不是被动共振决定了对歌曲频率的调谐主动放大和调谐有一个“开”和“关”状态蟋蟀是具有主动听觉放大功能的遗传学上最古老的昆虫
A dominant theme of acoustic communication is the partitioning of acoustic space into exclusive, species-specific niches to enable efficient information transfer. In insects, acoustic niche partitioning is achieved through auditory frequency filtering, brought about by the mechanical properties of their ears. The tuning of the antennal ears of mosquitoes and flies, however, arises from active amplification, a process similar to that at work in the mammalian cochlea. Yet, the presence of active amplification in the other type of insect ears—tympanal ears—has remained uncertain. Here we demonstrate the presence of active amplification and adaptive tuning in the tympanal ear of a phylogenetically basal insect, a tree cricket. We also show that the tree cricket exploits critical oscillator-like mechanics, enabling high auditory sensitivity and tuning to conspecific songs. These findings imply that sophisticated auditory mechanisms may have appeared even earlier in the evolution of hearing and acoustic communication than currently appreciated. Our findings also raise the possibility that frequency discrimination and directional hearing in tympanal systems may rely on physiological nonlinearities, in addition to mechanical properties, effectively lifting some of the physical constraints placed on insects by their small size and prompting an extensive reexamination of invertebrate audition. The tympanal ears of a tree cricket use active amplification Active amplification and not passive resonance determines tuning to song frequency Active amplification and tuning have an “on” and an “off” state Crickets are the phylogenetically oldest insects with active auditory amplification