Multisite analysis of hippocampal neuronal ensembles

海马神经元群的多位点分析

• 批准号: 10216361
• 负责人: JAMES J KNIERIM
• 金额: $ 50.29万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-12-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10216361
• 关键词: Alzheimer' s Disease; Anatomy; Animals; Attention; Behavior; Behavioral; Binding; Birds; Brain; Brain region; Cells; Chemosensitization; Cognitive; Conscious; Consensus; Cues; Data; Data Analyses; Disease; Dissociation; Emotions; Environment; Epilepsy; Episodic memory; Event; Eye; Head; Hippocampus (Brain); Human; Individual; Knowledge; Lateral; Lead; Learning; Life; Life Experience; Link; Literature; Location; Maps; Medial; Memory; Memory Loss; Memory impairment; Neocortex; Neurobehavioral Manifestations; Neurons; Organism; Rattus; Reporting; Rewards; Role; Running; Scanning; Sensory; Signal Transduction; Source; Stimulus; Stream; Stroke; Structure; Surface; System; Testing; Texture; Thinking; Time; Vision; cell cortex; entorhinal cortex; experience; experimental study; information processing; insight; memory encoding; nervous system disorder; neural circuit; neuromechanism; place fields; relating to nervous system; sensory input; sensory stimulus; sound; spatial memory; theories

PROJECT SUMMARY The hippocampus is a brain structure that is critical for normal learning and memory functions. One of the first brain regions to deteriorate in Alzheimer's Disease is the entorhinal cortex, the key processing stage between the neocortex and the hippocampus. This degeneration correlates with the memory deficits that are among the first cognitive symptoms of the disease. To understand why hippocampal damage causes such severe memory deficits, it is necessary to understand the basic computational functions of this brain region. The entorhinal cortex is divided into two regions: the medial entorhinal cortex (MEC) and the lateral entorhinal cortex (LEC). A long-standing theory hypothesizes that the hippocampus supports the conscious recall of autobiographical events (“episodic memory”) by binding the different aspects of an experience—the sights, sounds, thoughts, emotions, etc., experienced at a moment in one's life—onto a framework that represents the spatial context in which that experienced occurred. The MEC is thought to provide the hippocampus with this spatial framework, whereas the LEC is thought to represent the “item and events” of experience. Much is known about how the MEC represents space, but how the LEC represents experience is much less understood. The specific aims of this project are to test the hypothesis that the LEC encodes the location of attended items in the external world relative to the individual (i.e., an egocentric framework), whereas the MEC encodes both the locations of attended external items and the location of the individual in a world-centered coordinate system (i.e., an allocentric framework). Furthermore, we will test the hypothesis that the hippocampus incorporates new information within the spatial framework by creating new place fields when the rat performs a discrete, attentive behavior known as head scanning, especially when that behavior is accompanied by a reward. Finally, we will test the hypothesis that the hippocampus explicitly encodes the identity of nonspatial, surface texture cues experienced at a given location by modulating the firing rate of the place cell at that location (so-called rate remapping). The results of these experiments will provide crucial knowledge about how the brain encodes and stores representations of events within their spatial contexts, which underlies our abilities to form conscious memories of our life experiences.

项目概要 海马体是一种对于正常学习和记忆功能至关重要的大脑结构。第一个 阿尔茨海默病恶化的大脑区域是内嗅皮层，它是大脑和大脑之间的关键处理阶段。 新皮质和海马体。这种退化与记忆缺陷有关 该疾病的第一个认知症状。了解为什么海马损伤会导致如此严重的后果 记忆缺陷，有必要了解该大脑区域的基本计算功能。这 内嗅皮质分为两个区域：内侧内嗅皮质（MEC）和外侧内嗅皮质 皮质（LEC）。一个长期存在的理论假设海马体支持有意识地回忆 自传体事件（“情景记忆”）通过结合体验的不同方面——景点、 声音、思想、情感等，在一个人生命中的某个时刻经历过——到一个代表这个框架的框架上 经历发生的空间背景。 MEC 被认为为海马体提供了这种功能 空间框架，而 LEC 被认为代表体验的“项目和事件”。很多是 人们对 MEC 如何表示空间有所了解，但对 LEC 如何表示体验却知之甚少 明白了。该项目的具体目标是检验 LEC 编码位置的假设 参加与个人相关的外部世界的项目（即自我中心框架），而 MEC 对所关注的外部项目的位置和个人在以世界为中心的位置中的位置进行编码 坐标系（即非中心框架）。此外，我们将检验以下假设： 海马体通过在空间框架内创建新的场所字段来整合新信息 老鼠会执行一种离散的、专注的行为，称为头部扫描，尤其是当这种行为是 并附有奖励。最后，我们将检验海马体明确编码的假设 通过调节发射率来识别在给定位置经历的非空间、表面纹理线索 将单元放置在该位置（所谓的速率重新映射）。这些实验的结果将提供至关重要的 关于大脑如何在其空间环境中编码和存储事件表征的知识， 它是我们对生活经历形成有意识记忆的能力的基础。