Cell-type basis for auditory processing in the inferior colliculus

项目摘要 作为中枢听觉系统的主要中枢，下丘(IC)接受 来自听觉脑干核团的自下而上的输入，以及来自听觉皮质(AC)的反馈输入。 IC对处理用于交流的声音的基本特征和 本地化。IC处理能力受损与各种听力障碍有关。然而， 尽管对IC的中枢听觉处理进行了广泛的研究，但我们对特定细胞类型的理解 集成电路的功能作用背后的电路机制仍然有限。特别是，有多大的不同 颈内动脉三个解剖和功能亚区的神经元类型，中央核(ICC)， 背侧皮质(ICD)和外部皮质(ICE)相互作用，对 IC的听觉处理在很大程度上仍然不清楚。解决这个问题需要确定 细胞类型的分子标记，具体位于每个亚群中。10倍基因组学 单核RNA测序(SnRNAseq)，我们在筛选分子标记方面做了初步的努力 针对不同神经细胞群的IC。通过识别和验证IC细分的特定标记 并利用相应的转基因Cre小鼠品系来寻找所选的标记基因，然后我们将 描述所选细胞类型的解剖连接和听觉反应特性 它在听觉加工功能中的功能作用。我们的初步SnRNAseq结果显示有两个 潜在的分子标记专门标记大脑皮质兴奋性神经元亚群。 他们的核查将赋予我们独特的机会来调查具体和多样化的 ICD在听觉感知和行为中的功能作用。领先的方法 电生理学、解剖学和光遗传学与基于交叉或投影的标记相结合 也将应用于解决ICD中不同类型神经元的不同功能贡献 作为不同的基础电路机制。

Project Summary As a major hub of the central auditory system for hearing, the inferior colliculus (IC) receives both bottom-up input from auditory brainstem nuclei, as well as feed-back input from the auditory cortex (AC). IC contributes importantly to the processing of essential features of sounds for communication and localization. Impaired IC processing has been associated with various hearing deficits. However, despite extensive studies of central auditory processing in IC, our understanding of cell-type-specific circuit mechanisms underlying the functional roles of the IC remains limited. In particular, how different types of neurons in the three anatomical and functional subdivisions of IC, the central nucleus (ICc), dorsal cortex (ICd), and external cortex (ICe), interact with each other and contribute differentially to the auditory processing of IC remains largely unclear. Addressing this question requires identification of molecular markers for cell types specifically located in each of the subdivisions. With 10X Genomics single-nucleus RNA sequencing (snRNAseq), we made initial efforts in screening molecular markers for different neuronal populations of IC. By identifying and verifying specific markers for IC subdivisions and exploiting corresponding transgenic Cre mouse lines for the selected marker genes, we will then characterize the anatomical connections and auditory response properties of the selected cell type and its functional role in auditory processing functions. Our preliminary snRNAseq results suggest two potential molecular markers specifically labeling subpopulations of excitatory neurons in the IC cortex. Their verification will endow us with unique opportunities to investigate the specific and diverse functional roles of ICd in auditory perception and behavior. Cutting-edge approaches in electrophysiology, anatomy, and optogenetics coupled with intersectional or projection-based tagging will be applied to address the differential functional contribution of diverse neuronal types in ICd as well as the distinct underlying circuitry mechanisms.