Path Integration in the Rat Navigational System

描述(申请人提供)：当一只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。提供这种地图状表示的像元分为两部分 一般类别。一种称为放置单元格的类型在任何时候都会以最佳方式触发 老鼠在更大的环境中的一个特定位置。每个地方 细胞有它自己的高活动区，所以对于每个点，动物 访问时，有一组独特的细胞将处于活动状态。另一种类型是 称为头部方向细胞。当老鼠面对其中一个时，每一个都会开火 特定的方向，并将这样做，而不管老鼠的当前位置或 行为状态。由于每个单元格都有其自己的首选方向，因此存在 唯一的一组定向单元格，对于每个可能的标题都是活动的。 以前的工作；已经表明，Place单元格和Head Direction单元格 在一定程度上，依赖于一种称为路径整合的过程，以某种方式“跟踪” 老鼠的位置和方向。路径集成涉及 利用动物自身的运动不断更新空间射击 模式。例如，如果老鼠从位置‘A’开始，然后取了几个 达到B的步骤，这项动议本身将以某种方式导致A的位置 单元格关闭，而‘B’放置要打开的单元格。同样，如果动物 从“北”--信号头向神经元的活动开始，然后 向右转90度，这个角运动本身就会以某种方式转动 “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，Place和Head Direction系统可能各自具有 他们自己的路径集成电路位于特定的、识别的 边缘系统的脑干组件。拟议工作的目标将是 1)记录这些核中的细胞，以确定它们是否含有 已被假设为神经中路径整合所必需的信号 位置和头部方向细胞的网络模型，以及2)损害这些区域 并检查对Place和Head Direction单元格的影响 边缘系统。我们推测，这些细胞核的损伤应该会摧毁所有 在整个边缘系统放置和定向信号。 如果证实这些原子核确实构成了假定的路径 集成电路，这将为今后的重要工作提供基础。 路径集成是一种受限制的神经计算思想 复杂的认知图谱能力。此外，假设的电路 路径整合在形式上类似于许多其他路径的假设 认知功能，包括短期记忆和某些类型的视觉 感知力。因此，路径集成电路的标识用于 放置和头部方向系统将允许对一种类型的 一种可能在几种类型的高等教育中发挥核心作用的电路 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.