AUDITORY INFORMATION PROCESSING IN MIDBRAIN AND THALAMUS

声学行为依赖于投影系统所传递的信息 从下丘到内侧膝状体，再到 听觉皮质。这项研究的长期目标是评估 这些投影系统中的听觉信息处理。建议数 研究将检查神经元通过光谱分析和 时间上复杂的声音。特别注意解剖学 产生结合的联系和生理特性- 敏感神经元。这些神经元结合了响应于 在适当的时间关系中的不同频率，执行 复杂声音的计算分析。拟议的研究审查了 在胡子蝙蝠的听觉系统中，它们是最好的 明白了。 最初的实验使用生理记录描述了， 组合敏感神经元的功能特性和组织 在下丘。这些实验将引导我们逆行 识别听觉脑干核团的示踪研究 有助于小丘神经元的组合敏感反应。 生理记录将从听觉脑干获得 在先前的解剖学实验中确定的区域。这些遗嘱 提供检查组合敏感度是否起源于劣势 丘神经元，或位于较低水平。一种顺行追踪器将是 放置在听觉脑干区，似乎有助于 下丘的组合敏感性；这可以证实 对下丘组合敏感性的潜在贡献。 最后，化学灭活实验将检验推测的作用。 脑干核团在创造这些反应特征中的作用 丘脑。因为丘脑网状核似乎对 对内侧膝状体的组合敏感反应，其 功能特性和解剖联系也将被检查。 听觉引导的行为，包括言语和其他形式的 声学通信和声音定位，往往依赖于神经 将不同频段的信息组合在一起的机制。 胡子蝙蝠中的组合敏感神经元构成了一条主要途径 从下丘到内侧膝状体，再到 听觉皮层，在其中编码时间信息。在人类身上， 内侧膝状体的结构不规则已经被 与以时间加工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 在长胡子的蝙蝠身上可能提供了更深层次的理解 语音处理系统在人类体内运行。

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.