ENCODING OF VOCAL SIGNALS IN THE AUDITORY SYSTEM

我们计划的目标是了解 脊椎动物的听觉神经系统处理特定物种 声音信号。这项研究将集中在两个神经基础上 对这些信号以及潜在机制的识别 这使得它们的空间定位成为可能。我们的方法是基于 主要基于我们之前对无尾两栖动物的神经行为研究 (青蛙和蟾蜍)跨越过去的许多年。因为我们有 研究发现，人的外周和中枢听觉神经系统 不同的物种被选择性地调谐以检测特定的信号 在它们特定物种的广告呼叫中的特征，我们希望 继续探索其不同级别的转型 产生选择性的听觉系统。我们也会 开始研究声音中其他叫声的神经编码 用于确定是否有单独通道的曲目 处理这些其他重要的声音。来自单曲的录音 神经元将在第八神经，脑干核团， 在麻醉动物的前脑中，对 各种声音刺激，包括自然发声和合成发声 信号。从最近的一项行为研究中，我们有证据表明 无尾两栖动物依靠一种包括声音的压力梯度机制 通过咽鼓管连接到双侧正中 耳腔，以实现准确的声音定位。在一个 合作研究我们将使用激光测振技术来 描述这本小说中涉及的生物物理学原理 计划。我们相信，我们的整体研究结果 计划将提供对类似问题的必要洞察 高等脊椎动物发声信号的感觉处理 更难被拆解。我们确信， 对较低、更简单的声带脊椎动物的研究是有价值的 用于理解以下基本过程的模型 在人类听觉中产生了听觉和语音识别 神经系统。

The goal of our program is the understanding of how the vertebrate auditory nervous system processes species-specific vocal signals. This research will focus on both the neural basis of recognition of these signals as well as the underlying mechanisms that enable their spatial localization. Our approach is based primarily on our previous neurobehavioral studies of anurans (frogs and toads) spanning the past many years. Since we have found that the peripheral and central auditory nervous system of different species is selectively tuned to detect certain signal features in their species-specific advertisement calls, we wish to continue to explore the transformations at various levels of their auditory system which give rise to the selectivity. We also will begin studies of neural encoding of the other calls in their vocal repertoire to determine if there are separate channels for processing these other important sounds. Recordings from single neurons will be conducted in the eighth nerve, brainstem nuclei, and in the forebrain of anesthetized animals in response to a variety of acoustic stimuli including natural and synthetic vocal signals. From a recent behavioral study we have evidence that anurans rely on a pressure gradient mechanism involving sound coupling through their Eustachian tubes to their bilateral middle ear cavities in order to achieve accurate sound localization. In a collaborative study we will employ laser vibrometry to characterize the biophysical principles involved in this novel scheme. We believe that the results of our overall research program will provide needed insight into similar questions of sensory processing of vocal signals in higher vertebrates but which are much more difficult to unravel. We are convinced that studies of lower, simpler vocal vertebrates serve as valuable models for understanding the fundamental processes that have given rise to hearing and speech recognition in the human auditory nervous system.