Echoes of the Brain within the Posterior Cingulate Cortex
Echoes of the Brain within the Posterior Cingulate Cortex
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DOI：
10.1523/jneurosci.3689-11.2012
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发表时间：
2012-01-04
影响因子：
5.3
通讯作者：
Sharp, David J.
中科院分区：
文献类型：
--
作者：
Leech, Robert;Braga, Rodrigo;Sharp, David J.
关于后扣带皮层（PCC）的功能存在相当大的不确定性。PCC是默认模式网络（DMN）中的主要节点，具有高代谢活性和与广泛大脑区域的密集结构连接，这表明它具有皮质中枢的作用。该区域似乎参与了内部导向的思想，例如，记忆回忆。然而，最近的非人类灵长类动物的工作提供了证据，通过发出环境变化的信号和改变行为的需要，在控制认知方面发挥更积极的作用。为了让生物体能够灵活地对不断变化的环境做出反应，在功能不同的大脑网络中处理的信息需要通过这样一个皮层中枢进行整合。如果PCC参与了这一过程，它的大脑活动应该表现出复杂和动态的模式，部分反映了其他大脑网络的活动。使用fMRI在人类和多变量分析，我们证明，PCC显示这种类型的复杂的功能架构，其中多个其他大脑网络的回声被视为可分离但重叠的子区域。例如，一个主要的腹侧区域显示出强大的功能连接到DMN的其余部分，而背侧PCC内的两个子区域显示出高连接到额顶叶网络参与认知控制。PCC子区域表现出不同的模式的活动调制在性能的注意力要求高的任务，这表明背侧PCC的部分与额顶叶网络相互作用，以调节内部和外部定向认知之间的平衡。
There is considerable uncertainty about the function of the posterior cingulate cortex (PCC). The PCC is a major node within the default mode network (DMN) and has high metabolic activity and dense structural connectivity to widespread brain regions, which suggests it has a role as a cortical hub. The region appears to be involved in internally directed thought, for example, memory recollection. However, recent nonhuman primate work provides evidence for a more active role in the control of cognition, through signaling an environmental change and the need to alter behavior. For an organism to flexibly react to a changing environment, information processed in functionally distinct brain networks needs to be integrated by such a cortical hub. If the PCC is involved in this process, its brain activity should show a complex and dynamic pattern that partially reflects activity in other brain networks. Using fMRI in humans and a multivariate analysis, we demonstrate that the PCC shows this type of complex functional architecture, where echoes of multiple other brain networks are seen in separable yet overlapping subregions. For example, a predominantly ventral region shows strong functional connectivity to the rest of the DMN, whereas two subregions within the dorsal PCC show high connectivity to frontoparietal networks involved in cognitive control. PCC subregions showed distinct patterns of activity modulation during the performance of an attentionally demanding task, suggesting that parts of the dorsal PCC interact with frontoparietal networks to regulate the balance between internally and externally directed cognition.