Information processing in sensory systems

描述（由申请人提供）：该提案的总体目标是了解听觉系统处理的早期丘脑皮质阶段的功能组织。这涉及到对连接内侧膝状体（MGB）与第一和第二听觉皮层（A1和A2）的各种通路的更好的功能理解。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到A1/A2， A1到MGB和A1到A2通路完整。我们将通过光刺激或最小电刺激释放谷氨酸来测试这些谷氨酸能途径的功能，并将通过使用通道视紫质方法进行补充。特别是，我们将尝试将每个路径分类为1类（即以前的“驱动器”），2类（以前的“调制器”）或其他，因此我们希望构建信息流的功能层次结构。我们还将测试第6层皮质丘脑细胞在控制丘脑皮质传递中的作用，并测试复杂的假设，首先，存在平行的直接通路和皮质丘脑皮质通路连接A1和A2，其次，这些双重通路以巧合检测的方式运行以控制信息流。这也可以提供关于皮层功能的更普遍的见解，特别是关于不同皮层区域可以根据行为需要动态合作的新证据。

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.