The effects of acute aerobic exercise on hippocampal function and microstructure in older adults

项目概要/摘要 记忆力下降是老年人普遍的抱怨，可能会造成巨大的情绪、 对个人、他们的亲人和社会造成的身体和经济损失。与此同时，缺乏身体活动也是其中之一 痴呆症最重要的可改变危险因素。具体来说，锻炼和体力活动 干预措施似乎有利于并保护海马亚区结构，这些区域发挥着关键作用 在记忆过程中发挥重要作用，是神经退行性变和痴呆进展的早期部位。然而， 研究人员和公共卫生专家仍然不知道潜在的神经生理机制 哪种运动可以带来这些好处。没有全面了解运动的机理 对老化大脑的影响，仍然很难确定和实施优化和个性化的运动 培训干预。因此，利用先进的神经影像学和方法进行急性运动研究至关重要 行为测量来表征单次运动对神经生理学的潜在影响 老化的大脑。该拟议项目在以既定导师为中心的指导下提供了独特的培训机会 急性运动对老年人海马亚区功能和微观结构的影响。至 为了实现这一目标，我们将采用每位导师实验室开发的方法，包括模式分离 性能、基于任务的功能磁共振成像和基于 HARDI 的测量。这些数据具有成本效益和时间效率 然后，可以将急性运动研究与老年人的未来优化运动训练计划相结合并提供信息 有记忆缺陷和认知能力下降风险的成年人。以前的急性运动工作很少 使用神经影像技术或海马亚区特定认知任务，甚至更少 对老年人进行了此类研究。而之前我们证明了急性运动 引起海马体功能和结构的改变，在这里我们想在这项工作的基础上通过 同时检查急性运动对记忆表现和海马亚区的影响 功能和微观结构。因此，该项目的目的是使用一种对年龄敏感且高度敏感的 海马特定的模式分离任务，以及先进的功能和扩散成像方法 表征急性运动对老年人海马亚区微观结构和功能的影响 剧烈的中等强度有氧运动后。使用这些先进的成像协议和 在急性运动干预中，高度海马特异性和年龄敏感的行为范式将 帮助阐明有氧运动对重要的年龄敏感记忆网络的直接影响。的 这项研究的结果将有助于未来的临床试验实施优化的运动干预措施 神经生理学测量将提供信息并有益于理解运动对身体的影响 老化的大脑。此外，这一培训机会将有助于建立一个有希望的发展轨迹 独立科学家。

Project Summary/Abstract Memory decline is a pervasive complaint of older adults and can exact an enormous emotional, physical, and economic toll on individuals, their loved ones, and society. Meanwhile, physical inactivity is one of the most significant modifiable risk factors for dementia. Specifically, exercise and physical activity interventions appear to benefit and preserve the hippocampal subfield structures, regions that play a critical role in memory processes and are an early site of neurodegeneration and dementia progression. However, researchers and public health experts still do not know the underlying neurophysiological mechanisms by which exercise might afford these benefits. Without a comprehensive understanding of exercise's mechanistic effects on the aging brain, it remains hard to determine and implement optimized and individualized exercise training interventions. Thus, it is critical to conduct acute exercise studies using advanced neuroimaging and behavioral measures to characterize a single exercise session's underlying neurophysiological effects on the aging brain. This proposed project provides a unique training opportunity under established mentors centered on the impact of acute exercise on hippocampal subfield function and microstructure in older adults. To accomplish this, we will employ methods developed in each mentors’ laboratory, including pattern separation performance, task-based fMRI, and HARDI-based measures. The data from these cost- and time-efficient acute exercise studies can then be combined with and inform future optimized exercise training plans for older adults with memory deficits and who are at risk of cognitive decline. Previous acute exercise work has rarely used neuroimaging techniques or hippocampal subfield specific cognitive tasks, and even fewer have conducted these types of studies in older adults. Whereas previously we demonstrated that acute exercise elicits alterations in gross hippocampal function and structure, here we want to build on this work by concomitantly examining the impact of acute exercise on memory performance and hippocampal subfield function and microstructure. Therefore, the purpose of this project is to use an age-susceptible and highly hippocampal-specific pattern separation task, along with advanced functional and diffusion imaging methods to characterize the effects of acute exercise on hippocampal subfield microstructure and function in older adults following an acute bout of moderate-intensity aerobic exercise. Using these advanced imaging protocols and a highly hippocampal-specific and age-susceptible behavioral paradigm in an acute exercise intervention will help elucidate the immediate effects of aerobic exercise on important age-susceptible memory networks. The results of this study will help future clinical trials implement optimized exercise interventions and neurophysiological measures that will be informative and beneficial for understanding the effects of exercise on the aging brain. Furthermore, this training opportunity will help establish a promising trajectory as an independent scientist.