THE NEURAL BASIS OF INTERNAL REPRESENTATION OF PLACE

地点内部表征的神经基础

• 批准号: 3400630
• 负责人: BRUCE L MCNAUGHTON
• 金额: $ 8.67万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-03-01 至 1987-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3400630
• 关键词: discrimination learning; electroencephalography; evoked potentials; hippocampus; microelectrodes; neural information processing; neuromuscular system; neurophysiology; neuropsychology; orientation; single cell analysis; space perception

The objective of this project is to apply a new technique for the isolation of spike trains from several single neurons in behaving rats to the problem of how internal representations of familiar places are maintained upon removal of their initiating cues (i.e. "how does the organism continue to know where it is when the lights go out?"). There are two problems here. The first is to demonstrate beyond question that experimental animals (rats) actually do make use of internal representations to solve spatial problems. The second is to discover the neural basis of this ability. This proposal is based upon O'Keefe's and Nadel's hypothesis that the hippocampal formation acts as a cognitive mapping system. Apart from the lesion literature leading to this notion, its main support is the fact that hippocampal unit activity separates into two clear classes: 'place' cells which carry position and direction information, and 'theta' cells which fire during translational movements. These two types of information could form the elements of a cognitive mapping system. The extension of this theory presented here requires that a) specific stable patterns of neural discharge be set up whenever the animal finds itself in a familiar place, b) these patterns should exhibit hysteresis in that the place specific information required to maintain them should be much less than that required to initiate them (in the limit, all external information should be removable,) and c) learned correspondences between transitions among these neural states and the motor sequences leading to them should result in the ability of the system to reactivate an appropriate series of such place specific states on the basis of the corresponding motor sequences alone (given that some initial state has been set up by externally provided place information). The new recording method to be applied to this problem is based on the principle that cells which are a unique ratio of distances from two closely spaced electrodes will generate spikes with unique ratio of amplitudes on the corresponding recording channels. Evidence is presented that a method based on this principle effectively solves the perennial problems of single unit isolation in the hippocampus where cells are densely packed and may exhibit considerable intrinsic variation in spike amplitude. In addition, it removes some of the selection bias towards large cells, and permits analysis of interactions among spike trains recorded simultaneously from several neurons.

本项目的目的是应用一种新的隔离技术 从行为正常的老鼠身上的几个神经元发出的脉冲串 熟悉地点的内部表征是如何维持在 去除它们的启动线索（即“生物体如何继续 你知道灯灭了它在哪吗"). 这里有两个问题。 第一是毫无疑问地证明实验动物 （老鼠）实际上利用内部表征来解决空间问题。 问题 第二是发现这种能力的神经基础。 这一建议是基于奥基夫和纳德尔的假设， 海马结构充当认知映射系统。 除了 病变文献导致这一概念，其主要支持是这样一个事实， 海马单位的活动分为两个明确的类别：“位置”细胞 其携带位置和方向信息，以及“θ”细胞， 在平移运动中开火。 这两种信息可以 形成认知映射系统的元素。 扩大这种 这里提出的理论要求a）特定的稳定的神经模式， 当动物发现自己在熟悉的地方时， B）这些图案应该表现出滞后， 维护它们所需的信息应该比这少得多 （在限制范围内，所有外部信息都应 可移除的，）和c）这些之间的转换之间的学习对应 神经状态和导致它们的运动序列应该导致 系统重新激活适当系列此类场所的能力 仅基于相应的运动序列的特定状态 （假设某个初始状态已由外部提供的位置设置 信息）。 应用于该问题的新记录方法基于 原则是细胞是一个独特的距离比从两个接近 间隔的电极将产生具有独特的振幅比的尖峰， 对应的记录通道。 有证据表明，一种方法 基于这一原则，有效地解决了长期存在的问题， 海马体中的单位隔离，其中细胞密集， 在尖峰幅度上表现出相当大的固有变化。 此外，本发明还提供了一种方法， 它消除了一些对大细胞的选择偏见，并允许 分析同时记录的尖峰序列之间的相互作用， 几个神经元