https://scholars.lib.ntu.edu.tw/handle/123456789/598869
標題: | The Ageing Brain: Investigating the Role of Age in Changes to the Human Cerebral Microvasculature With an in silico Model | 作者: | Graff B.J Payne S.J STEPHEN JOHN PAYNE |
關鍵字: | capillaries;cerebral blood flow;healthy ageing;micro-emboli;neurodegenaration;adult;age;aged;aging;analytical parameters;Article;blood vessel occlusion;brain aging;brain blood flow;capillary;capillary permeability;cerebral microvasculature;cognitive defect;computer model;groups by age;healthy aging;human;microembolism;microvasculature;middle aged;nonhuman;risk assessment;risk factor;simulation;surface area to volume ratio | 公開日期: | 5-八月-2021 | 卷: | 13 | 來源出版物: | Frontiers in Aging Neuroscience | 摘要: | Ageing causes extensive structural changes to the human cerebral microvasculature, which have a significant effect on capillary bed perfusion and oxygen transport. Current models of brain capillary networks in the literature focus on healthy adult brains and do not capture the effects of ageing, which is critical when studying neurodegenerative diseases. This study builds upon a statistically accurate model of the human cerebral microvasculature based on ex-vivo morphological data. This model is adapted for “healthy” ageing using in-vivo measurements from mice at three distinct age groups—young, middle-aged, and old. From this new model, blood and molecular exchange parameters are calculated such as permeability and surface-area-to-volume ratio, and compared across the three age groups. The ability to alter the model vessel-by-vessel is used to create a continuous gradient of ageing. It was found that surface-area-to-volume ratio reduced in old age by 6% and permeability by 24% from middle-age to old age, and variability within the networks also increased with age. The ageing gradient indicated a threshold in the ageing process around 75 years old, after which small changes have an amplified effect on blood flow properties. This gradient enables comparison of studies measuring cerebral properties at discrete points in time. The response of middle aged and old aged capillary beds to micro-emboli showed a lower robustness of the old age capillary bed to vessel occlusion. As the brain ages, there is thus increased vulnerability of the microvasculature—with a “tipping point” beyond which further remodeling of the microvasculature has exaggerated effects on the brain. When developing in-silico models of the brain, age is a very important consideration to accurately assess risk factors for cognitive decline and isolate early biomarkers of microvascular health. ? Copyright ? 2021 Graff, Payne and El-Bouri. |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85113142968&doi=10.3389%2ffnagi.2021.632521&partnerID=40&md5=966493bf2956b47889267cc7dfb72649 https://scholars.lib.ntu.edu.tw/handle/123456789/598869 |
ISSN: | 16634365 | DOI: | 10.3389/fnagi.2021.632521 |
顯示於: | 應用力學研究所 |
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