Functional Connectivity between Cerebellum and Cerebrum: A Preliminary fMRI Study Based on BOLD Correlation

In previous studies, cerebellum had long been thought as only a part of the motor coordination system. However, more and more researches pointed out that cerebellum takes part in many other brain activities and even higher cognitive functions. In recent years, some studies focused on establishing anatomical atlas of cerebellum by using magnetic resonance imaging (MRI), while others concentrated on task-positive functional magnetic resonance imaging (fMRI) studies of the cerebellum.
Our study used non-invasive and task-free resting-state fMRI analysis to demonstrate the functional connectivity between different sub-regions of cerebellum and the whole cerebrum. We first applied four well-explored motor tasks to verify whether the results of resting fMRI analysis were comparable to those of traditional fMRI analysis. Secondly, the cerebellum was divided into 28 sub-regions based on its anatomical structures, and their blood oxygen level dependent (BOLD) correlations with whole cerebrum were analyzed respectively.
20 healthy subjects were enrolled. The results of region of interest (ROI)-based resting-state fMRI analysis revealed that the functional connectivity maps of different motor tasks were similar to those of the traditional BOLD fMRI analysis. Following this, the BOLD correlation analysis between 28 sub-regions of cerebellum and cerebrum were illustrated separately. Interestingly, sub-regions belonged to the same phylogenetic system displayed certain similar functional connectivity maps. Vestibulocerebellum had few BOLD correlations with cerebral cortex; spinocerebellum mainly contributing to the coordination system possessed strong BOLD correlations with motor-related cortexes; the youngest cerebrocerebellum had vigorous BOLD correlations with prefrontal and parietal lobes.