Path Integration in the Rat Navigational System

描述（由申请人提供）：当大鼠在太空中导航时，神经元 位于整个边缘系统提供了一个抽象的表示， 环境提供这种类似地图的表示的像元分为两种 一般类别。其中一种称为Place细胞， 大鼠处于较大环境中的一个特定位置。每个地方 细胞有自己的高放电区域，因此，对于每个点，动物 访问时，有一组独特的细胞将被激活。另一类是 称为头部方向细胞。每当老鼠面对一个 无论老鼠的当前位置如何， 行为状态由于每个单元格都有自己的首选方向， 唯一的一组方向单元，对于每个可能的航向都是活动的。 先前的工作表明，地点单元格和头部方向单元格 部分依赖于一个被称为路径整合的过程，以某种方式“跟踪” 老鼠的位置和方向路径整合包括 利用动物自身的运动来不断更新空间发射 模式.例如，如果大鼠从位置'A'开始，然后取几个 到达“B”的步骤，这个运动本身会以某种方式导致“A”位置 细胞关闭，而“B”放置细胞打开。同样，如果动物 开始于“北”信号头方向细胞的活动，然后 向右旋转90度，这个角运动本身， “北”头方向单元格关闭，“东”头方向单元格打开。 最近的数据表明，地点和头部方向系统可能各自具有 它们自己的路径积分电路位于特定的、标识的 边缘系统的脑干成分拟议工作的目标将 1）记录这些细胞核中的细胞，以确定它们是否含有 信号已被假定为必要的路径集成在神经 位置和头部方向细胞的网络模型，以及2）损伤这些区域 并检查对位置和头部方向细胞在其他部分的影响， 边缘系统我们假定，这些核团的损伤应该破坏所有的 位置和方向信号遍布边缘系统。 如果证实这些原子核确实构成了假设的路径 集成电路，这将为未来的重要工作提供基础。 路径整合是一种诡辩的神经计算思想， 复杂的认知映射能力。此外，电路假设为 路径整合在形式上类似于许多其他 认知功能，包括短期记忆和某些类型的视觉 perception.因此，用于所述电路的路径积分电路的识别是困难的。 地点和头部方向系统将允许详细研究一种类型的 电路，这是可能发挥核心作用，在几种类型的高等 认知功能

DESCRIPTION (provided by applicant): As a rat navigates through space, neurons located throughout the limbic system provide an abstract representation of the environment. The cells which provide this map-like representation fall into two general categories. One type, known as Place cells, fires optimally whenever the rat is in one particular location within the larger environment. Each Place cell has its own region of high firing, so that for each spot the animal visits, there is a unique set of cells which will be active. The other type is known as Head Direction cells. Each of these fires whenever the rat faces one particular direction and will do so regardless of the rat's current location or behavioral state. Since each cell has its own preferred direction, there is a unique set of directional cells which are active for each possible heading. Previous work; has shown that both the Place cells and the Head Direction cells rely, in part, on a process known as path integration, to somehow "track" the rat's location and directional heading, respectively. Path integration involves the use of the animal's own movement to constantly update the spatial firing patterns. For example, if the rat begins at, location 'A', and then takes a few steps to arrive at 'B', this motion itself will, somehow, cause the 'A' Place cells to turn off, and the 'B' Place cells to turn on. Similarly, if the animal begins with activity in the 'north'-signaling Head Direction cells, and then turns 90 degrees to the right, this angular motion will, itself, somehow turn the 'north' Head Direction cells off, and the 'east' Head Direction cells on. Recent data suggest that the Place and Head Direction systems may each have their own path integration circuitry located within particular, identified brainstem components of the limbic system. The goal of the proposed work will be 1) to record from cells in these nuclei to determine whether they contain signals which have been postulated as necessary for path integration in neural network models of Place and Head Direction cells, and 2) to lesion these areas and examine the effects on Place and Head Direction cells in other parts of the limbic system. We postulate that lesions of these nuclei should destroy all Place and Directional signals throughout the limbic system. If it is verified that these nuclei do, in fact, constitute the postulated path integration circuitry, this will provide a basis for important future work. Path integration is a sophistocated neural computation thought to underly complex cognitive mapping abilities. In addition, the circuitry postulated for path integration is formally similar to that postulated for numerous other cognitive functions, including short term memory and certain types of visual perception. Thus the identification of the path integration circuitry for the Place and Head Direction systems would allow for detailed study of a type of circuit which is likely to play a central role in several types of higher cognitive function.