Functional relationships between visual cortex and thalamus

我们将首先使用小鼠大脑的体外切片制剂来研究丘脑皮质 视觉系统中两个方向的相互作用，集中在皮质区V1和V2 丘脑核团LGN和Lp。然后我们建议开发体内制剂来测试 来自体外实验的假说。我们大量使用光遗传学与其他 激活特定通路的刺激范例，并使用单细胞记录和 电流源密度分析以测量响应。我们对这个角色特别感兴趣 两个不同的皮质丘脑投射。一个从第6层发出，并反馈到 丘脑核团支配该区域；我们假设它的主要功能是抑制 丘脑皮质的多种互补机制传递。另一种是散发出 从第5层开始，以前馈方式组织，支配不 支配它的皮质区域；我们假设这代表着一个跨丘脑的启动， 皮质-丘脑-皮质通路与皮质直接投射平行组织。 最后，我们还将检验这两条路径同时运行的假设 以检测方式控制信息流。这可能会提供更全面的见解 关于皮质功能，特别是关于不同皮质功能的新证据 区域可以根据行为需求进行动态协作。

We shall initially use in vitro slice preparations from the mouse brain to study thalamocortical interactions in both directions in the visual system, concentrating on cortical areas V1 and V2 and thalamic nuclei LGN and LP. We then propose to develop in vivo preparations to test hypotheses from the in vitro work. We make heavy use of optogenetics in combination with other stimulation paradigms to activate specific pathways and use both single cell recording and current source density analysis to measure responses. We are particularly interested in the role of the two distinct corticothalamic projections. One emanates from layer 6 and feeds back to the thalamic nucleus innervating that area; we hypothesize that its main function is to depress thalamocortical transmission by multiple complementary mechanisms. The other emanates from layer 5 and is organized in a feed forward fashion, innervating thalamic regions that do not innervate its cortical area; we hypothesize that this represents the initiation of a transthalamic, cortico-thalamo-cortical pathway organized in parallel with direct corticocortical projections. Finally, we shall also test the hypothesis that these dual pathways operate in a coincidence detection manner to control information flow. This could provide more general insights regarding cortical functioning, particularly with respect to new evidence that different cortical areas can dynamically cooperate depending on behavioral needs.