AUDITORY INFORMATION PROCESSING IN MIDBRAIN AND THALAMUS

声学行为依赖于投影系统所传达的信息 从下丘到奖牌膝状体，然后到 听觉皮层这项研究的长期目标是评估 听觉信息处理在这些投射系统中。拟议 研究将检查神经元进行光谱分析的机制， 时间复杂的声音。特别注意解剖学 连接和生理特性，从而产生组合- 敏感神经元这些联合收割机的神经元， 在适当的时间关系中的不同频率， 复杂声音的计算分析。拟议的研究审查 这些在胡子蝙蝠的听觉系统中， 明白 最初的实验描述了，使用生理记录， 组合敏感神经元的功能特性和组织 在下丘这些实验将引导逆行 跟踪研究，确定听觉脑干核， 有助于丘神经元的组合敏感性反应。 将从听觉脑干获得生理记录 在前面的解剖实验中确定的区域。这些将 提供检查组合敏感性是否源于劣 丘神经元，或在较低的水平。顺行追踪器将 位于脑干听觉区， 下丘的组合敏感性;这可以证实 可能导致下丘组合敏感性。 最后，化学灭活实验将测试假定的作用 脑干神经核团在创造这些反应特征中的作用 丘因为丘脑网状核似乎 内侧膝状体的组合敏感反应，其 还将检查功能特性和解剖学连接。 声音引导的行为，包括言语和其他形式的 声学通信和声音定位，通常依赖于神经 联合收割机在不同频带上组合信息的机制。 在胡子蝙蝠的组合敏感神经元形成一个主要的途径 从下丘到内侧膝状体，然后到 听觉皮层，时间信息在其中被编码。在人类中， 内侧膝状体的结构不规则， 与以时间处理为特征的语言障碍有关 赤字组合敏感神经元产生机制的研究 也许能让我们更深入地了解 语音处理系统在人类中运行。

Acoustic behavior relies on information conveyed by projection systems from the inferior colliculus to the medal geniculate body and then to the auditory cortex. The long term goal of this research is to evaluate auditory information processing in these projection systems. The proposed research will examine mechanisms by which neurons analyze spectrally and temporally complex sounds. Special attention is placed on anatomical connections and physiological properties which give rise to combination - sensitive neurons. These neurons, which combine inputs responding to different frequencies in the appropriate temporal relationships, perform computational analyses of complex sounds. The proposed studies examine these in the mustached bat auditory system, where they are best understood. The initial experiments describe, using physiological recording, functional properties and organization of combination-sensitive neurons in the inferior colliculus. These experiments will guide retrograde tracing studies that identify auditory brain stem nuclei which may contribute to the combination-sensitive response of collicular neurons. Physiological recordings will be obtained from auditory brain stem regions identified in the preceeding anatomical experiments. These will provide examine whether combination sensitivity originates in inferior colliculus neurons, or at lower levels. An anterograde tracer will be placed in an auditory brain stem region that appears to contribute to combination sensitivity in the inferior colliculus; this can confirm a potential contribution to inferior collicular combination sensitivity. Finally, chemical inactivation experiments will test the presumed role of brain stem nuclei in creating these response features in the colliculus. Because the thalamic reticular nucleus appears to contribute to combination-sensitive responses in the medial geniculate body, its functional properties and anatomical connections will also be examined. Acoustically-guided behavior, including speech and other forms of acoustic communication and sound localization, often relies on neural mechanisms which combine information across different frequency bands. Combination-sensitive neurons in the mustached bat form a major pathway from the inferior colliculus to the medial geniculate body, and then to the auditory cortex, in which temporal information is encoded. In humans, structural irregularities in the medial geniculate body have been implicated in language disorders characterized by temporal processing deficits. Studies of mechanisms creating combination-sensitive neurons in mustached bats may provide a deeper understanding of how analagous speech processing systems operate in humans.