FREQUENCY SPECIFIC ANALYSIS REVEALED THE IMBALANCED FUNCTIONAL NETWORKS IN OBSESSIVE-COMPULSIVE DISORDER

. Dysfunction of the fronto-striatal circuit is repeatedly reported in obsessive-compulsive disorder. The abnormality of the functional connectivity (FC) of this circuit is also reported and the deep brain stimulation is showed to restore it. However, the directions of the reported abnormalities are not consistent and the more detailed analysis is needed. The blood-oxygen-level-dependent (BOLD) signal obtained from the functional magnetic resonance imaging (fMRI) scans is usually analyzed after some preprocessing steps including band-pass filtering (typically, 0.010-0.080 Hz). The frequency of the filtering is decided considering the signal-noise ratio, while this band width involve two bands having different functions; slow-4 band (0.027-0.073 Hz) and slow-5 band (0.010-0.027 Hz) (Buzsaki et al., 2004). Here we conducted the frequency specific analysis of the functional networks. The participants are 37 non-medicated patients with OCD and 38 matched healthy volunteers. We obtained resting state fMRI scans and preprocessed BOLD data with slow-4 band and slow-5 band. Then we calculated voxelwise statistical parametric maps testing strength of functional connectivity of three striatal seed regions of interest (ROIs) in each hemisphere with remaining brain regions between groups. We found the significantly decreased FC between the dorsal caudate and the dorsolateral prefrontal cortex only with the slow-5 band data (peak level corrected p