fMRI ANALYSIS OF MEDIAL TEMPORAL LOBE FUNCTION IN AGING AND AD

描述（由申请人提供）：本项目的目标是使用功能磁体 磁共振成像（fMRI），以评估与年龄相关的内侧颞叶（MTL）功能（或其他大脑区域的功能）的变化之间的关系，以及与年龄相关的工作记忆和陈述性或外显记忆的变化。MTL神经病理学与阿尔茨海默病（AD）中的严重陈述性记忆障碍密切相关，但越来越多的证据表明，老年人中的轻度记忆障碍也与MTL功能障碍相关，并且这种障碍可能标志着AD的临床前阶段，至少在这些个体中的一些中。主要重点将是在工作记忆表现和结构中的编码和检索期间发生的神经激活，例如额叶和海马结构以及包括MTL的海马旁回的部分。将检查这些区域的MTL激活的编码、检索（重点是成功和不成功检索项目的编码），并在包括年轻和老年对照组、轻度认知记忆障碍（MCI-记忆）患者和轻度AD患者的组间进行比较。第二个重点将是在编码和提取过程中发生在其他新皮层区域（特别是额叶区域）的神经激活。其他数据将包括高分辨率结构MRI和高分辨率扩散张量成像（DTI），以量化大脑的宏观和微观结构体积和完整性。后者的一部分 该项目将与项目1合作开展。在合作工作中，这两个体内项目已经证明了健康和病理老化中宏观和微观结构白色物质完整性的显著变化。Gabrieli博士和他的合作者不仅能够研究四组之间这些指标的差异，还能够研究认知表现与区域白色物质完整性之间的关系。此外，这些数据将提供重要的信息的相互作用的功能磁共振成像信号和变化的全球和区域的体积和完整性在健康和病理老化。

DESCRIPTION (provided by applicant): The goal of this Project is to use functional magnet resonance imaging (fMRI) to evaluate the relationship between age-associated changes in medial temporal lobe (MTL) function (or the function of other brain regions), and age-associated changes in working memory and declarative or explicit memory. MTL neuropathology is closely related to severe declarative memory failure in Alzheimer's disease (AD), but there is growing evidence that milder memory impairment in older individuals is also associated with MTL dysfunction, and that this impairment may signal a preclinical stage of AD, in at least some of these individuals. The primary emphasis will be neural activation that occurs during working memory performance and encoding and retrieval in structures, such as the frontal lobes, and the hippocampal formation as well as parts of the parahippocampal gyrus that comprise the MTL. MTL activation in these areas will be examined for encoding, retrieval (with an emphasis on encoding of successfully and unsuccessfully retrieved items), and compared across groups comprising young and elderly controls, patients with mild cognitive impairment of memory (MCl-memory), and those with mild AD. Secondary emphasis will be neural activation that occurs during encoding and retrieval in other neocortical areas (particular frontal regions). Additional data will include high-resolution structural MRI and high resolution diffusion tensor imaging (DTI) to quantify macro and microstructural volume and integrity of the brain. Part of the latter Project will be carried out in collaboration with Project 1. In collaborative work, the two in vivo projects have demonstrated significant changes in macro- and microstructural white matter integrity in healthy and pathological aging. In this application, Dr. Gabrieli and his collaborators will be able to investigate not only differences in these measures between the four groups, but also the relationship between cognitive performance and regional white matter integrity. In addition, these data will provide important information on the interaction of fMRI signal and changes in global and regional volume and integrity in healthy and pathological aging.