Functional connector hubs in the cerebellum

Accumulating evidence from anatomical and neuroimaging studies suggests that the cerebellum is engaged in a variety of motor and cognitive tasks. Given its various functions, a key question is whether the cerebellum also plays an important role in the brain's integrative functions. Here, we hypothesize the existence of connector regions, also known as connector hubs, where multiple resting state networks converged in the cerebellum. To verify this, we employed a recently developed voxel-level network measure called functional connectivity overlap ratio (FCOR), which could be used to quantify the spatial extent of a region's connection to several large-scale cortical networks. Using resting state functional MRI data from 101 healthy participants, cerebellar FCOR maps were constructed and used to identify the locations of connector hubs in the cerebellum. Results showed that a number of cerebellar regions exhibited strong connectivity with multiple functional networks, verifying our hypothesis. These highly connected regions were located in the posterior cerebellum, especially in lobules VI, VII, and IX, and mainly connected to the core neurocognitive networks such as default mode and executive control networks. Regions associated with the sensorimotor network were also localized in lobule V, VI, and VIII, albeit in small clusters. These cerebellar connector hubs may play an essential role in the processing of information across the core neurocognitive networks.

来自解剖学和神经影像学研究的越来越多的证据表明，小脑参与多种运动和认知任务。鉴于其多种功能，一个关键问题是小脑是否在大脑的整合功能中也起着重要作用。在此，我们假设存在连接区域，也称为连接枢纽，即多个静息态网络在小脑中汇聚的区域。为了验证这一点，我们采用了一种最近开发的体素级网络测量方法，称为功能连接重叠率（FCOR），它可用于量化一个区域与几个大规模皮质网络连接的空间范围。利用101名健康参与者的静息态功能磁共振成像数据，构建了小脑FCOR图谱，并用于确定小脑中连接枢纽的位置。结果显示，一些小脑区域与多个功能网络表现出强连接，验证了我们的假设。这些高度连接的区域位于小脑后部，特别是在第六、第七和第九小叶，并且主要与默认模式和执行控制等核心神经认知网络相连。与感觉运动网络相关的区域也位于第五、第六和第八小叶，尽管是小的集群。这些小脑连接枢纽可能在核心神经认知网络间的信息处理中起着至关重要的作用。