Information processing in sensory systems

描述（由申请人提供）：该提案的主要目标是了解听觉系统中早期丘脑皮层处理阶段的功能组织。这涉及到更好地了解连接内侧膝状体（MGB）以及第一和第二听觉皮层（A1和A2）的各种通路的功能。我们将使用小鼠大脑的体外切片制备，其中不同的切片配置将使MGB至A1/A2、A1至MGB和A1至A2通路完整。我们将通过光刺激或最小电刺激来释放谷氨酸，以测试这些谷氨酸能通路中的每一个的功能，并且这将通过使用通道视紫红质方法来补充。特别地，我们将尝试将每个途径分类为1类（即，以前称为“驱动器”）、第2类（以前称为“调制器”）或其他，因此我们希望构建信息流的功能层次结构。我们还将测试的作用，第6层皮质丘脑细胞门控丘脑-皮质的传输和测试复杂的假设，首先，存在平行的直接和皮质丘脑-皮质通路连接A1与A2，第二，这些双重途径的操作在一个巧合的检测方式来控制信息流。这也可以提供关于皮质功能的更一般的见解，特别是关于不同皮质区域可以根据行为需求动态合作的新证据。 公共卫生相关性：我们必须更好地理解听觉信息流通过皮层处理的前几个阶段，以开始理解这些通路中的病理如何导致听力损失，包括认知听觉功能的缺陷，如词汇语义处理，语音信息提取，选择性注意和物体识别。

DESCRIPTION (provided by applicant): The broad goal of the proposal is to understand the functional organization of the early thalamocortical stages of processing in the auditory system. This involves a better functional understanding of the various pathways connecting the medial geniculate body (MGB) plus first and second auditory cortices (A1 and A2). We will use an in vitro slice preparation of the mouse brain in which different slice configurations will have the MGB to A1/A2, A1 to MGB, and A1 to A2 pathways intact. We will use uncaging of glutamate by photostimulation or minimal electrical stimulation to test the function of each of these glutamatergic pathways, and this will be complemented by the use of channelrhodopsin methodology. In particular, we shall attempt to classify each pathway as Class 1 (i.e., formerly "driver"), Class 2 (formerly "modulator"), or other, and thereby we hope to construct a functional hierarchy of information flow. We shall also test the role of layer 6 corticothalamic cells in gating thalamocortical transmission and test the complex hypothesis, first, that there exists parallel direct and corticothalamocortical pathways linking A1 with A2, and second, that these dual pathways operate in a coincidence detection manner to control information flow. This could also provide more general insights regarding cortical functioning, particularly with respect to new evidence that different cortical areas can dynamically cooperate depending on behavioral needs. PUBLIC HEALTH RELEVANCE: We must better understand auditory information flow through the first few stages of cortical processing to begin to understand how pathology in these pathways leads to hearing loss including defects in cognitive auditory functions, such as lexical-semantic processing, phonological information extraction, selective attention and object recognition.