COMPUTATIONAL BASIS OF THE HEAD DIRECTION CELL SIGNAL

头部方向细胞信号的计算基础

• 批准号: 2685734
• 负责人: PATRICIA E SHARP
• 金额: $ 11.05万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-04-01 至 2000-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2685734
• 关键词: behavior test; brain electrical activity; cell population study; electrical measurement; histology; laboratory rat; neuroanatomy; psychomotor function

As a rat navigates through space, neurons known as Head Direction cells provide an ongoing indication of momentary directional heading. Each cell fires when the animal is facing one particular direction. Every cell has its own firing direction, so that each heading is signalled by activity in a unique subset of these cells. It is not clear how these signals are generated. Surprisingly, there is no evidence for geomagnetic influences. Rather, the cells are influenced, in part, by visual cues; salient visual landmarks can "set" the darkness. Thus, the cells must also use cues which signal angular head motion (e.g., vestibular or visual motion cues) since, in the absence of landmarks, these are the only ongoing indicators of directional heading. Head Direction cells have been found in several interconnected brain regions, including the postsubiculm, retrosplenial cortex, laterodorsal thalamic nucleus, and anterior thalamic nuclei. These areas, in turn, are connected to several other regions, including the reticular thalamic nucleus, mammillary bodies, pretectal area and superior colliculus. Cells in the latter areas have not yet been examined for direction correlates. The goal of these studies is to examine each area in this circuit for the presence of cells (other than Head Direction cells themselves) which could constitute the building blocks for the head direction signal. Cells in each area will be recorded as animals navigate while performing a food pellet retrieving task. The animals will be equipped with two headlights, which provide a continual indication of the animal's momentary directional heading. Cell activity in each area will be examined for any directional, visual, or angular motion correlates. The sensory basis of any such signals will be examined in probe studies including 1) lights out sessions to test for visual influences. 2) passive rotation sessions, to test for dependence on the animal's own motor movements, and 3) delivery of experimenter-generated vestibular and visual motion cues. When completed, the proposed studies, along with earlier work, will provide a complete examination of the basic navigation related firing properties in the Head Direction cell circuit. This will provide a basis for development of a theoretical explanation for these cells. This is an important goal because 1) it will provide an example of how a neural circuit can generate a highly abstract representation (head direction), and 2) it will provide insight into one aspect of the overall set of cognitive and perceptual abilities involved in navigation.

当大鼠在太空中导航时，被称为头部方向细胞的神经元 提供瞬时航向的持续指示。每个单元格 当动物面对一个特定的方向时，就会触发。每个细胞都有 它有自己的射击方向，所以每个航向都是通过 这些细胞的一个独特的子集。 目前尚不清楚这些信号是如何产生的。令人惊讶的是，没有 地磁影响的证据。相反，细胞受到影响，在 部分是由视觉线索决定的；突出的视觉地标可以“设置”黑暗。 因此，单元还必须使用发信号通知头部角运动的提示(例如， 前庭或视觉运动提示)，因为在没有地标的情况下，这些 是目前唯一的航向指示器。 在几个相互连接的大脑中发现了头部方向细胞 区域，包括下丘脑后、脾后皮质、背外侧 丘脑核团和丘脑前核。这些领域反过来又是 连接到其他几个区域，包括网状丘脑 核、乳头体、顶盖前区和上丘。单元格 在后几个领域，尚未审查方向相关性。 这些研究的目标是检查这个环路中的每个区域 单元格(头部方向单元格本身除外)的存在，可能 构成磁头方向信号的积木。单元格 每个区域将被记录为动物在执行食物时导航 小球回收任务。这些动物将配备两个前灯， 它们提供了动物瞬间方向的连续指示 航向。每个区域的细胞活动将被检查是否有任何方向， 视觉运动或角运动与此相关。任何这样的感官基础 信号将在探测研究中进行检查，包括1)熄灯时间 以测试视觉影响。2)被动轮换会话，用于测试 依赖动物自身的运动动作，以及3)分娩 由实验者生成的前庭和视觉运动提示。 完成后，拟议的研究以及较早前的工作将提供 中与导航相关的基本射击特性的完整检查 磁头方向单元电路。这将为发展提供基础 对这些细胞的理论解释。这是一个重要的目标 因为1)它将提供一个神经电路如何产生 高度抽象的表示(头部方向)，以及2)它将提供 洞察整个认知和感知集合的一个方面 与导航有关的能力。