Organization of cortico-cortical pathways supporting memory retrieval across subregions of the left ventrolateral prefrontal cortex
Organization of cortico-cortical pathways supporting memory retrieval across subregions of the left ventrolateral prefrontal cortex
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DOI：
10.1152/jn.00157.2016
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发表时间：
2016-09-01
影响因子：
2.5
通讯作者：
Badre, David
中科院分区：
文献类型：
--
作者：
Barredo, Jennifer;Verstynen, Timothy D.;Badre, David
功能性磁共振成像（fMRI）证据表明，腹外侧前额叶皮层（VLPFC）的不同亚区参与不同的皮层网络。这些网络已被证明支持可分离的认知功能：前部VLPFC[下额回（IFG）眶部]在功能上与腹侧额颞网络相关，该网络与自上而下对记忆检索的影响相关，而中侧VLPFC （IFG三角部）在功能上与背侧额顶叶网络相关，该网络与记忆后控制过程相关。然而，目前尚不清楚网络隶属关系和功能的分区域差异在多大程度上是由潜在白质通路组织差异驱动的。我们使用高角分辨率扩散光谱成像和功能连接分析在未麻醉的人，以解决白质连接的组织是否在VLPFC的亚区不同。我们的研究结果表明，在IFG中存在腹-背分裂。腹侧IFG作为一个整体广泛连接外侧颞叶皮层。尽管在腹侧IFG和外侧颞叶皮层之间有几个不同的白质束形成连接，但功能性mri数据的功能连通性分析表明，它们是同一个腹侧功能网络的一部分。相比之下，在各个细分中，背侧IFG与额叶中回相连，并作为一个单独的背侧功能网络相互关联。在VLPFC更大的宏观解剖亚区中，这些白质组织的质性差异支持了在基于任务和功能连接的fMRI研究中观察到的这些区域之间的先前功能差异。这些结果与解剖连通性是额叶皮层和大脑系统级功能组织的关键决定因素的建议一致。
Functional magnetic resonance imaging (fMRI) evidence indicates that different subregions of ventrolateral prefrontal cortex (VLPFC) participate in distinct cortical networks. These networks have been shown to support separable cognitive functions: anterior VLPFC [ inferior frontal gyrus (IFG) pars orbitalis] functionally correlates with a ventral fronto-temporal network associated with top-down influences on memory retrieval, while mid-VLPFC (IFG pars triangularis) functionally correlates with a dorsal fronto-parietal network associated with postretrieval control processes. However, it is not known to what extent subregional differences in network affiliation and function are driven by differences in the organization of underlying white matter pathways. We used high-angular-resolution diffusion spectrum imaging and functional connectivity analysis in unanesthetized humans to address whether the organization of white matter connectivity differs between subregions of VLPFC. Our results demonstrate a ventral-dorsal division within IFG. Ventral IFG as a whole connects broadly to lateral temporal cortex. Although several different individual white matter tracts form connections between ventral IFG and lateral temporal cortex, functional connectivity analysis of fMRI data indicates that these are part of the same ventral functional network. By contrast, across subdivisions, dorsal IFG was connected with the midfrontal gyrus and correlated as a separate dorsal functional network. These qualitative differences in white matter organization within larger macroanatomical subregions of VLPFC support prior functional distinctions among these regions observed in task-based and functional connectivity fMRI studies. These results are consistent with the proposal that anatomical connectivity is a crucial determinant of systems-level functional organization of frontal cortex and the brain in general.