National Brain Research Centre, Manesar, Gurgaon, Haryana, India.
Center for Brain Research and Applications, School of AIDE, IIT Jodhpur, Karwar, Rajasthan, India.
Commun Biol. 2022 Jun 9;5(1):567. doi: 10.1038/s42003-022-03489-4.
We propose that the preservation of functional integration, estimated from measures of neural synchrony, is a key objective of neurocompensatory mechanisms associated with healthy human ageing. To support this proposal, we demonstrate how phase-locking at the peak alpha frequency in Magnetoencephalography recordings remains invariant over the lifespan in a large cohort of human participants, aged 18-88 years. Using empirically derived connection topologies from diffusion tensor imaging data, we create an in-silico model of whole-brain alpha dynamics. We show that enhancing inter-areal coupling can cancel the effect of increased axonal transmission delays associated with age-related degeneration of white matter tracts, albeit at slower network frequencies. By deriving analytical solutions for simplified connection topologies, we further establish the theoretical principles underlying compensatory network re-organization. Our findings suggest that frequency slowing with age- frequently observed in the alpha band in diverse populations- may be viewed as an epiphenomenon of the underlying compensatory mechanism.
我们提出，从神经同步性的测量中估计出的功能整合的保留，是与健康人类衰老相关的神经补偿机制的关键目标。为了支持这一建议，我们展示了在一个由 18 岁至 88 岁的大量人类参与者组成的大型队列中，脑磁图记录中的峰值 alpha 频率的相位锁定如何在整个生命周期中保持不变。我们使用从弥散张量成像数据中得出的经验衍生的连接拓扑结构，创建了一个全脑 alpha 动力学的计算机模型。我们表明，增强区域间的耦合可以抵消与白质束年龄相关退化相关的轴突传输延迟增加的影响，尽管在较慢的网络频率下。通过为简化的连接拓扑结构推导解析解，我们进一步确定了补偿网络重新组织的理论原理。我们的研究结果表明，在不同人群中广泛观察到的 alpha 波段中的频率减慢-可能被视为潜在补偿机制的表象。
