Resting state functional connectivity of the limbic cerebellum in ASD : vermis lobules IV, VII, and IX
Cerebellar abnormalities have been identified in patient populations with disruptions in emotional functioning, often associated with the limbic system. Functional imaging research has provided evidence for a limbic cerebellum. Areas of the cerebellum, including the cerebellar vermis, have been shown to participate in emotional processing functions traditionally related to that of limbic system structures. However, the functional connectivity of specific areas of cerebellar vermis has not been extensively researched using resting-state functional connectivity magnetic resonance imaging (rs-fcMRI). Additionally, emotional processing deficits, often related to limbic system functioning, are associated with multiple patient populations including autism spectrum disorder (ASD). ASD is a pervasive neurodevelopmental disorder associated with deficits in language, social, and cognitive functioning. The cerebellum is one of the most consistent sites of brain abnormality in ASD; however, the connections between the cerebellar vermis and the limbic system have yet to be explored in this population using rs-fcMRI. The purpose of the present study was to investigate the functional connectivity of the limbic cerebellum using a resting-state fcMRI procedure in both typically developing individuals and those with ASD. This study aimed to increase current understanding of the organization of the brain, potential functions of the cerebellum, and provide insight into a disorder with established cerebellar abnormalities through the investigation of the connections of the cerebellar vermis in both typically developing individuals and those with ASD. Results indicated significant functional connectivity between three distinct areas of cerebellar vermis (vermis lobules IV, VII, and IX) and structures of the limbic system, including the cingulate gyrus, for the control group. Functional correlations between these regions suggest potential for cerebellar involvement in emotional processes, warranting further study. There were no differences in functional connectivity found for the superior posterior and inferior posterior vermis in ASD when compared to controls. An increase in anterior vermis functional connectivity in the ASD group extended to a small area in the left cingulate gyrus, a limbic system region. Results suggest limited differences in cerebellar vermis functional connectivity between groups.