1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China; 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China; 3Department of Anatomy, The University of Hong Kong, Hong Kong SAR, China
Changes in connectivity strength or spatial map of the low-frequency fluctuations in resting-state fMRI are the common focus when comparing the normal and diseased brains. However, limited work has studied the underlying spectral alterations. In this study, we investigated the spectral changes of resting-state connectivity in a rat model of complete corpus callosum (CC) transection. Interhemispheric connectivity was disappeared in cortical regions where the corresponding callosal connections were severed. Spectral analysis of these regions showed stronger power at relative high frequency around 0.1 Hz in transection group than in sham group. These spectral changes were observed in brain regions showing predominately intrahemispheric connectivity and therefore may arise from the faster intrahemispheric communication. Our experimental findings indicate that spectral characteristics of rsfMRI connectivity can be modulated by neural disruption and spectral analysis of rsfMRI data may provide a new dimension of information regarding the brain organization and connectivity.