Functional anatomy of the auditory system

描述（由申请人提供）：听觉系统由上行通路和下行通路组成，上行通路将信息从耳朵传输到感知声音的皮层，下行通路从皮层调节上行信息的处理和流动。下行通路在多种功能中发挥作用，包括选择性注意、学习、频率选择性、声音定位和语音辨别。最近的研究表明，下行通路和脑干胆碱能系统之间的密切联系。乙酰胆碱参与了许多刚刚列出的听觉功能，以及对新刺激的唤醒和检测。由于缺乏有关神经元回路的信息，对下行和胆碱能系统的各种功能的理解受到了阻碍。目前的建议将结合联合收割机多标记的解剖追踪技术与多标记的免疫组织化学，以确定这些电路的组件和突触组织。实验将集中在下丘，中脑的一部分，参与听觉感知的途径，以及许多方面的神经驱动的行为。这些结果将为解释生理和行为实验提供一个框架，并将为设计更先进的实验提供必要的数据，以检查这些途径的功能并确定潜在的细胞机制。

DESCRIPTION (provided by applicant): The auditory system consists of ascending pathways that transmit information from the ear to the cortex, where sound is perceived, and descending pathways from the cortex that modulate the processing and flow of ascending information. The descending pathways play a role in a wide variety of functions, including selective attention, learning, frequency selectivity, sound localization, and discrimination of speech sounds. Recent work has shown close ties between the descending pathways and the brainstem cholinergic system. Acetylcholine has been implicated in many of the same auditory functions just listed as well as arousal and detection of novel stimuli. Understanding the various functions of the descending and cholinergic systems has been impeded by lack of information on the underlying neuronal circuitry. The present proposal will combine multi-labeling anatomical tracing techniques with multi-labeling immunohistochemistry to identify the components and synaptic organization of these circuits. The experiments will focus on the inferior colliculus, a part of the midbrain that is involved in pathways for auditory perception as well as numerous aspects of auditory-driven behavior. The results will provide a framework for interpreting physiological and behavioral experiments, and will provide essential data for designing more advanced experiments to examine both the functions of these pathways and to determine the underlying cellular mechanisms.