Origins of Binaural Processing in Vertebrates

描述(申请人提供)：陆地动物使用双耳处理来帮助它们检测、辨别、定位和分离声源。中枢听觉系统的所有区域都参与了用于这些一般听力任务的计算，但哺乳动物和鸟类脑干的几个核团在双耳处理方面得到了最深入的研究。最近对鱼类的观察，包括行为、中枢听觉系统形态以及外周和中枢神经生理学，都表明从外周到脑的信息流不仅在所有种类的有颌脊椎动物中遵循相同的一般模式，而且听觉本身可能在这些类群中是同源的，最早是在早期鱼类中发展起来的。这反过来又表明，双耳处理可能也最先在早期鱼类中发展起来。在这项提议中，我们的目标是首次系统地研究鱼类(牡蛎蟾鱼-Opsanus tau)双耳听力的策略和机制。这些在活体中结合使用自然声学和双侧机械耳石操作的研究，将首次系统地描述和分析鱼类的双耳处理过程，并将有助于确定在陆地动物中观察到的哪些双耳机制是原始的，或者在脊椎动物中共享的，以及哪些机制可能是最近派生的。我们假设，双耳处理的几个基本结构和功能方面是原始脊椎动物的特征，我们希望它们在鱼类的听觉脑干中得到初步揭示。这项工作将有助于我们理解听觉系统和听觉的进化，从而有助于建立一个生物学和进化的背景，在这个背景下，可以更好地理解和应用人类听力和人类听力动物模型。

DESCRIPTION (provided by applicant): Terrestrial animals use binaural processing to help them detect, discriminate, locate, and segregate sounds sources. All regions of the central auditory system participate in the computations used for these general tasks of hearing, but several nuclei of the mammalian and avian brainstem have been most intensively studied with respect to binaural processing. Recent observations on fishes, including behavior, central auditory system morphology and peripheral and central neurophysiology converge in suggesting not only that the flow of information from the periphery to the epencephalon follows the same general pattern in all classes of jawed vertebrates, but that the sense of hearing itself may be homologous within these taxa, having first developed among early fishes. This, in turn, suggests that binaural processing may have first developed in early fishes, too. In this proposal, we aim to systematically investigate, for the first time, the strategies and mechanisms of binaural hearing in a fish (oyster toadfish - Opsanus tau). These studies using combinations of natural acoustic and bilateral mechanical otolith manipulation, in vivo, will provide the first systematic description and analysis of binaural processing in a fish, and will help determine what binaural mechanisms observed in terrestrial animals are primitive, or shared among vertebrates, and what mechanisms are likely to have been more recently derived. We hypothesize that several fundamental structural and functional aspects of binaural processing are primitive vertebrate characters and we expect them to be primitively revealed in the auditory brainstem of fishes. This work will contribute to our understanding of the evolution of auditory systems and the sense of hearing, and thereby help establish a biological and evolutionary context within which human hearing and animal models for human hearing can be better understood and applied.