凹耳蛙高频听觉的分子与神经机理

The concave-eared torrent frog (Odorrana tormota) is an endemic Chinese species and has recently been shown to have ability to produce and detect ultrasounds. It is the first non-mammal demonstrated to communicate ultrasonically. The high-frequency acoustic communication facilitates the frog to precisely localize sound sources and is likely an evolutionary adaptation in a noisy habitat. Sound is a mechanical wave. In order to be coded and processed in the central nervous system, the mechanical wave must be converted into electrical signals by mechanically sensitive transducer channels. The mechano-electrical transductions lie at the hair cells of the auditory organs. A key member of our project, Prof. Junxian Shen, has made great contribution to the field of high-frequency acoustic communication in the frogs (Feng et al., Nature, 2006; Shen et al., Nature, 2008; Gridi-Papp et al., PNAS, 2008; Shen et al., Nature Communations, 2011). To further understand the neural and biophysical mechanisms, we plan to study 1) Biophysical mechanisms of precise sound source localization. How do the concave-eared torrent frogs interpret the received signals to determine the location of a sound source? 2) Information processing of high-frequency sounds in the auditory centers of the frog. 3) The roles of ion channels distributed in auditory hair cells in the frog. The project is of significance to understand auditory evolutions in frogs and may help to develop new technology for improving hearing in noise.

凹耳蛙为中国特有蛙种，它产生并检测超声，是第一个被证实采用超声通讯的非哺乳类动物。高频声通讯有利于凹耳蛙进行精确声源定位；利用高频声通讯是凹耳蛙应对环境噪声干扰的有效策略。声波是一种机械能信号，只有通过内耳毛细胞上机械力感受型离子通道的换能作用转换为电信号，才可由神经细胞感知和传输。我国在凹耳蛙高频声通讯研究方面已处于世界前沿(2006及2008年在Nature，2007年在PNAS，2011年在Nat. Commun.上均发表了相关论文)。为继续保持优势，揭示凹耳蛙高频听觉的分子与神经机理，本项目拟从整体水平研究高频超声信号在凹耳蛙超精度声源定位中的作用及其生物物理机制；在系统水平研究凹耳蛙听觉神经系统对高频声信号的中枢加工；在分子水平研究离子通道在凹耳蛙高频声信号转换为神经电信号中的作用。研究成果不仅能加深对声通讯和听觉进化科学意义的理解，还有助于开发治疗听力损失的新技术。

主要研究内容：从整体水平研究高频超声信号在凹耳蛙超精度声源定位中的作用及其生物物理机制；在系统水平研究凹耳蛙听觉神经系统对高频声信号的中枢加工；在分子水平研究离子通道在凹耳蛙高频声信号转换为神经电信号中的作用。.重要结果：.1. 发现并证实凹耳蛙进化Lombard效应机制（SCI论文，2016年发表）.2. 证实自然噪声对凹耳蛙高频声通讯影响较小（SCI论文，2015年发表）.3. 证实凹耳蛙同域共生的大绿蛙听觉灵敏度存在性别差别（SCI论文，2014年发表）.科学意义：.提供了强噪声下凹耳蛙高频声通讯的新知识，加深了对高频听觉进化的理解。