Department of Psychiatry, Yale University, New Haven, CT 06519, USA.
Cereb Cortex. 2012 Jan;22(1):99-111. doi: 10.1093/cercor/bhr088. Epub 2011 May 13.
The medial superior frontal cortex (SFC), including the supplementary motor area (SMA) and presupplementary motor area (preSMA), is implicated in movement and cognitive control, among other functions central to decision making. Previous studies delineated the anatomical boundaries and functional connectivity of the SMA. However, it is unclear whether the preSMA, which responds to a variety of behavioral tasks, comprises functionally distinct areas. With 24 seed regions systematically demarcated throughout the anterior and posterior medial SFC, we examined here the functional divisions of the medial SFC on the basis of the "correlograms" of resting-state functional magnetic resonance imaging data of 225 adult individuals. In addition to replicating segregation of the SMA and posterior preSMA, the current results elucidated functional connectivities of anterior preSMA-the most anterior part of the medial SFC. In contrast to the caudal medial SFC, the anterior preSMA is connected with most of the prefrontal but not with somatomotor areas. Overall, the SMA is strongly connected to the thalamus and epithalamus, the posterior preSMA to putamen, pallidum, and subthalamic nucleus, and anterior preSMA to the caudate, with the caudate showing significant hemispheric asymmetry. These findings may provide a useful platform for future studies to investigate frontal cortical functions.
内侧额上回（SFC），包括辅助运动区（SMA）和前辅助运动区（preSMA），除了与决策相关的其他功能外，还涉及运动和认知控制。以前的研究描绘了 SMA 的解剖边界和功能连接。然而，尚不清楚对各种行为任务有反应的 preSMA 是否包含功能上不同的区域。我们使用 24 个种子区域系统地标定了前内侧 SFC 的前后，根据 225 名成年个体的静息状态功能磁共振成像数据的“相关图”，在此研究了内侧 SFC 的功能分区。除了复制 SMA 和后 preSMA 的分离外，当前的结果还阐明了前 preSMA 的功能连接 - 内侧 SFC 的最前部分。与尾部内侧 SFC 相反，前 preSMA 与大部分前额叶而非躯体运动区域相连。总的来说，SMA 与丘脑和上丘强烈相连，后 preSMA 与壳核、苍白球和丘脑底核相连，前 preSMA 与尾状核相连，尾状核显示出显著的半球不对称性。这些发现可能为未来的研究提供一个有用的平台，以研究额叶皮层功能。
