3-D firing properties of head direction and grid cells

项目摘要/摘要 研究计划描述了两个实验，这些实验将检查空间信息是如何在 哺乳动物的大脑--特别是在三维(3-D)空间导航方面。上一首 研究已经确定了一组神经元，称为头部方向细胞，其放电是一种 动物在水平面上的定向航向的作用。HD细胞主要是 记录在二维空间中。不同的理论假设了它们在3D空间中的反应方式。 目标1将通过记录HD细胞来验证这些理论，因为动物在 三维立方体的表面。特别是，我们将确定细胞激活是否与动物一样具有传递性。 从地板到垂直墙到顶面的不同路线。每一种理论都使 不同的预测是，当动物到达顶端表面时，细胞将如何激发。第二个空间 细胞类型是内嗅皮层中的网状细胞。当动物处于多个位置时，这些细胞会被激发； 这些位置形成了一个规则的、重复的六边形图案，形成了一个网格。目标2将评估电网如何 像元在环境中占据相同位置但偏移的两个水平面上触发 在垂直平面上。我们将确定两个表面之间的网格图案是对齐的还是 彼此之间的偏移。了解格网单元在这些条件下的响应方式非常重要 对理解网格单元信号是如何产生的影响。总而言之，这些研究将提供 洞察3-D空间信息在大脑中的组织和处理方式，并将增强我们的 了解HD和网格细胞在导航过程中的功能作用。结果是 对人类健康和行为的影响。前庭功能障碍患者和 阿尔茨海默病患者，这种疾病通常与边缘系统的显著病理有关 结构，以体验空间迷失的程度，需要不断的监督。 研究空间信息在大鼠大脑中是如何处理的，将给我们提供关于这个复合体的线索 人类空间过程的本质。

Project Summary/Abstract The Research Plan describes two experiments that will examine how spatial information is processed in the mammalian brain – particularly in regards to navigation in three-dimensional (3-D) space. Previous studies have identified a population of neurons, referred to as head direction cells, that discharge as a function of the animal’s directional heading in the horizontal plane. HD cells have primarily been recorded in two-dimensional space. Different theories have postulated how they respond in 3-D space. Aim 1 will test these theories by recording HD cells as an animal locomotes different routes on the surface of a 3-D cube. In particular, we will determine whether cell firing is comutative as the animal travels different routes from the floor up the vertical walls to the top surface. Each theory makes different predictions as how the cells will fire when the animal reaches the top surface. A second spatial cell type are grid cells in the entorhinal cortex. These cells fire when the animal is at multiple locations; the locations form a regular, repeating hexagonal pattern that forms a grid. Aim 2 will assess how grid cells fire across two horizontal planes that occupy the same location in the environment, but are offset in the vertical plane. We will determine if the grid patterns between the two surfaces are in alignment or offset from one another. Knowing how grid cells respond under these conditions has important implications for understanding how the grid cell signal is generated. In sum, these studies will provide insight into how 3-D spatial information is organized and processed in the brain and will enhance our understanding of the functional role of HD and grid cells during navigation. The results have implications for human health and behavior. It is common for patients with vestibular disorders and patients with Alzheimer’s disease, a disease often associated with marked pathology in limbic system structures, to experience spatial disorientation to the extent that constant supervision is required. Learning how spatial information is processed in the rat brain will give us clues about the complex nature of spatial processes in humans.