Structural and Functional Connectivity in the Dynamic Aging Brain

理由：在加拿大，65岁以上的个人数量有史以来第一次超过了儿童（14岁以下）的数量。根据加拿大统计局的数据，到2036年，加拿大的老年人数量将达到1090万。考虑到我们相对年龄分布的变化，目前迫切需要更好地理解随着个体年龄增长而发生的变化，特别是考虑到绝大多数认知神经科学研究都集中在年轻人身上。与衰老相关的最著名的变化是认知能力的变化。这些变化被认为是正常的，是意料之中的。然而，迄今为止的研究将认知变化与潜在的大脑结构和功能联系起来，并没有将大脑概念化为一个相互联系和动态的系统，因此未来的研究必须纳入结构和功能连接的先进措施。研究项目：我的研究项目的首要目标是利用先进的多模态成像方法了解人类大脑衰老的潜在神经关联。我的NSERC发现资助项目将使用基于结构和功能连接的磁共振成像测量来检查衰老和认知的脚手架理论。具体来说，这项研究将回答以下问题：大脑连接的微观结构特征如何随着年龄的增长而变化？随着年龄的增长，功能性网络会变得更活跃还是更不活跃？这些结构和功能连通性的变化是如何与认知相关的？性别、压力或体育活动等特定变量会导致大脑中积极或消极的神经可塑性变化吗？当我们跟踪一组个体的衰老过程时，结构和功能连接以及它们与认知的关系是如何随着时间而变化的？总的来说，这一全面而极其新颖的研究项目将描述人类大脑作为一个动态系统是如何随着年龄而变化的。这项工作将质疑和推进当前的老龄化理论，并提高当前对人口老龄化的认识。

Rationale: In Canada, the number of individuals over age sixty-five has exceeded the number of children (under age fourteen) for the first time in history. According to Statistics Canada, the number of seniors in Canada could reach 10.9 million by 2036. Given the shift in our relative age distribution, there is currently a crucial need to better understand the changes that occur as individuals age, especially given that the vast majority of cognitive neuroscience research has focused on young adults. Among the most well-known shifts associated with aging are changes in cognitive ability. These changes are considered normal and are to be expected. However, the research to date that has linked cognitive change to underlying brain structure and function, has not conceptualized the brain as a interconnected and dynamic system and it is essential for future research to incorporate advanced measures of structural and functional connectivity. Research Program: The overarching goal of my research program is to understand the underlying neural correlates of aging in the human brain using advanced multimodal imaging methods. My NSERC Discovery Grant program will use magnetic resonance imaging based measures of structural and functional connectivity to examine the Scaffolding Theory of Aging and Cognition. Specifically, this research will answer the following questions: How do microstructural characteristics of the brain's connections change with age? Do functional networks become more or less active as we age? How do these changes in structural and functional connectivity relate to cognition? Do certain variables such as sex, stress, or physical activity lead to positive or negative neuroplastic changes in the brain? How do structural and functional connectivity and their relationship with cognition change over time, as we follow one set of individuals through the aging process?  Taken together, this comprehensive and extremely novel program of research will characterize how the human brain as a dynamic system changes with age. The work will interrogate and advance current theory on aging, and enhance current understanding of our aging population.