Thalamo-cortex spatial-temporal organization in aging

这项试点研究要求获得资金，为NIH计划项目拨款给老龄化研究所获取人类初步数据，该项目计划结合动物和人类成像技术，以获取衰老过程中的脑功能基线。目前的试点方案旨在证明对衰老过程中的正常人脑功能进行长期纵向研究的可行性。这项纵向研究将利用脑磁图(MEG)的电生理功能成像，在某些情况下结合MRI成像。主要目的将是建立自上而下/自下而上的活动，作为丘脑-皮质基线动力学的一部分，以及它们随年龄的变化。我们有理由提出，智力减慢是衰老过程的特征，部分原因是由于认知任务中同步和一致性的改变，导致了电路计时问题。在这项先导性研究中，我们的目标是在早期感觉加工和视觉认知记忆任务中获得初步的脑磁图数据。脑磁图分析将使用处理频域和时间域信号的新技术。我们的工作假设是，尽管感觉加工是由专门的单位完成的，但认知绑定过程是跨通道的共同机制。更重要的是，当这种时间依赖的结合改变时，将导致感觉运动整合的改变，从而影响老化大脑的认知。这一假设将通过在健康的年轻人和老年人身上使用不同类型的感觉刺激的脑磁图手段来验证。

This pilot study requests funds to acquire human preliminary data for an NIH Program Project grant to the Aging Institute that plans to combine animal and human imaging techniques to access functional brain baselines during the aging process. The present pilot proposal will aim at demonstrating feasibility for a long-term longitudinal study on normal human brain function during aging. This longitudinal study will utilize electrophysiological functional imaging using magnetoencephalography (MEG) in some cases combined with MRI imaging. The main thrust will be to establish top-down / bottom up activity as part of thalamo-cortical baseline dynamics and their changes with age. We have reasons to propose that the intellectual slowing, characteristic of the aging process, is in part a circuit timing problem due to altered synchronization and coherence during cognitive tasks. In this pilot study we aim at acquiring preliminary MEG data during early sensory processing and during visual cognitive memory tasks. The MEG analysis will use new techniques that address frequency domain, as well as time domain, signals. Our working hypothesis is that although sensory processing is achieved by dedicated units, the cognitive binding process is a common mechanism across modalities. More over, it is proposed that such time dependent binding when altered, will result in modifications of sensory motor integration that will affect cognition in the aging brain. This hypothesis will be tested by magnetoencephalographic means using different types of sensory stimuli in healthy young and older subjects.