人类海马亚区的连接结构及功能机制的MRI研究进展  

Advances in the MRI study of connectivity structure and functional mechanism of hippocampal subregions in humans

作　　者：孙丽丽 任鹏[1] 李志鹏 李斯玚 刘秋逸[1,2] 梁夏 Lili Sun;Peng Ren;Zhipeng Li;Siyang Li;Qiuyi Liu;Xia Liang(School of Life Science and Technology,Harbin Institute of Technology,Harbin 150001,China;Laboratory for Space Environment and Physical Sciences,Harbin Institute of Technology,Harbin 150001,China)

机构地区：[1]哈尔滨工业大学生命科学与技术学院,哈尔滨150001 [2]哈尔滨工业大学空间环境与物质科学研究院,哈尔滨150001

出　　处：《科学通报》2021年第35期4510-4523,共14页Chinese Science Bulletin

基　　金：国家自然科学基金(82072000)资助。

摘　　要：海马是大脑中最为重要的区域之一,主要参与和负责学习、记忆等功能.近年来,海马各个亚区的结构和功能愈发地受到人们的关注.研究发现,利用高分辨率结构和功能磁共振成像技术能够获得海马各个亚区较为明确的解剖结构及功能连接,不同的海马亚区能够分别执行模式分离(pattern separation)和/或模式完成(pattern completion)等基本计算过程,且具有功能特异性.另一方面,研究发现,许多神经精神疾病(如阿尔茨海默病等)与海马内各亚区及其特定环路的异常变化有关.本文以海马亚区的解剖结构及功能连接为基础,沿着海马内经典的三突触回路(DG→CA3→CA1),回顾了近年来海马亚区相关的研究成果.以动物海马方面的相关研究为切入点,重点阐述了人类海马内各亚区及相关的海马外皮层所具备的功能,及其与常见的神经系统退行性疾病之间的关系,同时提出当前存在的一些问题及未来的研究方向.The hippocampus, a structure critical for learning and memory, consists of anatomical heterogenous subfields, including the dentate gyrus(DG), cornu ammonis(CA) 1-4, and subiculum(SUB). Evidences from studies on rodents and nonhuman primates have shown that the hippocampal subfields are richly connected, especially through the canonical trisynaptic pathway to project incoming information from the cortex via the entorhinal cortex(EC) to innervate the DG, and from here, intra-hippocampal connectivity is considered to follow a unidirectional pathway through the CA regions to the SUB, which is the primary region of efferent projection from the hippocampus. However, given their lower spatial resolution, it has been a challenge to map the hippocampal subfields in-vivo in the human brain, including their anatomical/functional connectivity and functional specificity. Recent developments in high-resolution structural and functional magnetic resonance imaging(MRI) techniques have allowed for detailed parcellation of the hippocampal subfields in humans and have provided new insights into their structure and function. In this review, we first briefly introduce the anatomical structure of the hippocampal subfields along the tri-synaptic pathway. We then review recent findings regarding the delineated patterns of anatomical and functional connectivity among the hippocampal subfields and neighboring cortical areas using high-resolution structural and functional MRI. In general, patterns of FC between hippocampal subfields and adjoining cortical regions of interest(ROIs) align well with the canonical intra-hippocampal anatomical circuitry(DG→CA3→CA1→SUB). Next, we discuss functional and computational mechanisms that could be subserved by different hippocampal subfields, with a special focus on two fundamental functional/computational processes: Pattern separation and pattern completion. Here, we start by introducing important findings from rodent studies regarding pattern separation/pattern completion functions in hippocam

关 键 词：海马亚区 三突触回路 功能连接 模式分离/模式完成 磁共振成像 

分 类 号：R445.2[医药卫生—影像医学与核医学]