Romero-Garcia Rafael, Atienza Mercedes, Cantero Jose L
Laboratory of Functional Neuroscience, Spanish Network of Excellence for Research on Neurodegenerative Diseases (CIBERNED), University Pablo de Olavide, Seville, Spain.
Hum Brain Mapp. 2014 Jun;35(6):2724-40. doi: 10.1002/hbm.22362. Epub 2013 Sep 12.
Understanding how the mammalian neocortex creates cognition largely depends on knowledge about large-scale cortical organization. Accumulated evidence has illuminated cortical substrates of cognition across the lifespan, but how topological properties of cortical networks support structure-function relationships in normal aging remains an open question. Here we investigate the role of connections (i.e., short/long and direct/indirect) and node properties (i.e., centrality and modularity) in predicting functional-structural connectivity coupling in healthy elderly subjects. Connectivity networks were derived from correlations of cortical thickness and cortical glucose consumption in resting state. Local-direct connections (i.e., nodes separated by less than 30 mm) and node modularity (i.e., a set of nodes highly interconnected within a topological community and sparsely interconnected with nodes from other modules) in the functional network were identified as the main determinants of coupling between cortical networks, suggesting that the structural network in aging is mainly constrained by functional topological properties involved in the segregation of information, likely due to aging-related deficits in functional integration. This hypothesis is supported by an enhanced connectivity between cortical regions of different resting-state networks involved in sensorimotor and memory functions in detrimental to associations between fronto-parietal regions supporting executive processes. Taken collectively, these findings open new avenues to identify aging-related failures in the anatomo-functional organization of the neocortical mantle, and might contribute to early detection of prevalent neurodegenerative conditions occurring in the late life.
了解哺乳动物新皮层如何产生认知很大程度上取决于对大规模皮层组织的认识。积累的证据揭示了整个生命周期中认知的皮层基础，但在正常衰老过程中，皮层网络的拓扑特性如何支持结构-功能关系仍是一个悬而未决的问题。在这里，我们研究连接（即短/长连接和直接/间接连接）和节点属性（即中心性和模块性）在预测健康老年人功能-结构连接耦合中的作用。连接网络源自静息状态下皮层厚度与皮层葡萄糖消耗的相关性。功能网络中的局部直接连接（即相隔小于30毫米的节点）和节点模块性（即一组在拓扑群落内高度互连且与其他模块的节点稀疏互连的节点）被确定为皮层网络之间耦合的主要决定因素，这表明衰老过程中的结构网络主要受信息分离所涉及的功能拓扑特性的限制，这可能是由于与衰老相关的功能整合缺陷所致。这一假设得到了参与感觉运动和记忆功能的不同静息状态网络的皮层区域之间增强连接的支持，而这种增强连接不利于支持执行过程的额顶叶区域之间的关联。总的来说，这些发现为识别新皮层幔层解剖-功能组织中与衰老相关的故障开辟了新途径，并可能有助于早期检测晚年普遍发生的神经退行性疾病。
