Functional and Structural Connectivity in Adolescence

描述(申请人提供)：儿童在青春期获得了复杂的推理技能，特别是在执行功能和工作记忆方面。然而，人们对这些变化的神经生物学基础知之甚少。关于这一问题的少数研究表明额叶及其联系的成熟。直到最近，还很难获得关于额叶在活体内成熟的相关信息。身体样本一直很稀少。磁共振成像的最新进展有望提供更多关于活体大脑功能和解剖连接的知识。这项拟议的研究利用这些创新来增加青春期额叶连接的知识。在一项横断面研究中，将使用新的磁共振成像技术对正常青少年进行研究。具体地说，功能连接性的发育变化将通过分析休息和工作记忆任务期间血液含氧量依赖信号的低频波动的时间相关性来评估。结构连通性将使用扩散张量成像和纤维跟踪进行评估。实质上，这项研究旨在建立工作记忆网络中与年龄相关的功能和结构连接性变化的正常模式，并将它们与青春期状态和荷尔蒙水平联系起来。在方法上，该项目寻求创建测量功能和结构大脑连接的技术，可以扩展到感兴趣的临床人群和其他认知领域。

DESCRIPTION (provided by applicant): Children gain sophisticated reasoning skills, particularly in executive function and working memory, during the adolescent years. Yet, little is known of the neurobiological substrate of these changes. The few studies bearing on this question implicate the maturation of the frontal lobe and its connections. Until recently, it has been difficult to obtain relevant information on frontal lobe maturation in vivo. Postmortem samples have been sparse. Recent advances in magnetic resonance imaging promise to provide increased knowledge of functional and anatomical brain connectivity in vivo. The proposed research exploits these innovations to increase knowledge of frontal lobe connectivity during the adolescent years. Normal adolescents will be studied using novel magnetic resonance imaging techniques within a cross-sectional study. Specifically, developmental changes in functional connectivity will be assessed via analysis of temporal correlations in low-frequency fluctuations of the blood-oxygenated level dependent signal during rest and during a working memory task. Structural connectivity will be evaluated using diffusion tensor imaging and fiber tracking. Substantively, the research aims to establish normal patterns of age-related change in functional and structural connectivity in the working memory network and relate them to pubertal status and hormonal levels. Methodologically, the project seeks to create techniques for measuring functional and structural brain connectivity that can be extended to clinical populations of interest and other cognitive domains.