德国柏林夏里特医院Benjamin Judkewitz研究团队揭示鱼类定向听觉的机制。2024年6月19日，《自然》杂志在线发表了这项成果。

研究人员在最小的脊椎动物之一——透明硬骨鱼Danionella cerebrum身上对这些模型进行了实证检验。通过选择性地控制压力和粒子运动，研究人员剖析了定向声惊吓的感官算法。研究人员发现这两种线索对于这种行为都是不可或缺的，而且它们的相对相位控制着行为的方向。通过使用微型计算机断层扫描和光学振动测量法，研究人员进一步证明了大脑具有实现这一机制的感觉结构。超过15%的脊椎动物与D. cerebrum具有相同的结构，这表明推断声音方向的机制非常普遍。

研究人员表示，确定猎物或捕食者等声源的位置对许多脊椎动物的生存至关重要。陆生脊椎动物通过测量两耳声压的时间延迟和强度差异来定位声源。然而，在水下，声音的物理特性使得耳际线索非常小，这表明鱼类几乎不可能有定向听觉。然而，定向听觉已在行为上得到证实，尽管其机制几十年来一直不为人知。人们提出了几种假说来解释这种非凡的能力，包括鱼类可能演化出了对微小耳间差异的极端敏感性，或者鱼类可能将声压与颗粒运动信号进行了比较。然而，长期以来，实验上的挑战一直阻碍着对其做出明确的解释。

附：英文原文

Title: The mechanism for directional hearing in fish

Author: Veith, Johannes, Chaigne, Thomas, Svanidze, Ana, Dressler, Lena Elisa, Hoffmann, Maximilian, Gerhardt, Ben, Judkewitz, Benjamin

Issue&Volume: 2024-06-19

Abstract: Locating sound sources such as prey or predators is critical for survival in many vertebrates. Terrestrial vertebrates locate sources by measuring the time delay and intensity difference of sound pressure at each ear1,2,3,4,5. Underwater, however, the physics of sound makes interaural cues very small, suggesting that directional hearing in fish should be nearly impossible6. Yet, directional hearing has been confirmed behaviourally, although the mechanisms have remained unknown for decades. Several hypotheses have been proposed to explain this remarkable ability, including the possibility that fish evolved an extreme sensitivity to minute interaural differences or that fish might compare sound pressure with particle motion signals7,8. However, experimental challenges have long hindered a definitive explanation. Here we empirically test these models in the transparent teleost Danionella cerebrum, one of the smallest vertebrates9,10. By selectively controlling pressure and particle motion, we dissect the sensory algorithm underlying directional acoustic startles. We find that both cues are indispensable for this behaviour and that their relative phase controls its direction. Using micro-computed tomography and optical vibrometry, we further show that D.cerebrum has the sensory structures to implement this mechanism. D.cerebrum shares these structures with more than 15% of living vertebrate species, suggesting a widespread mechanism for inferring sound direction.

DOI: 10.1038/s41586-024-07507-9

Source: https://www.nature.com/articles/s41586-024-07507-9