Frequency Dependent Alterations in Regional Homogeneity of Baseline Brain Activity in Schizophrenia

Abstract

Low frequency oscillations are essential in cognitive function impairment in schizophrenia. While functional connectivity can reveal the synchronization between distant brain regions, the regional abnormalities in task-independent baseline brain activity are less clear, especially in specific frequency bands. Here, we used a regional homogeneity (ReHo) method combined with resting-state functional magnetic resonance imaging to investigate low frequency spontaneous neural activity in the three different frequency bands (slow-5∶0.01–0.027 Hz; slow-4∶0.027–0.08 Hz; and typical band: 0.01–0.08 Hz) in 69 patients with schizophrenia and 62 healthy controls. Compared with controls, schizophrenia patients exhibited decreased ReHo in the precentral gyrus, middle occipital gyrus, and posterior insula, whereas increased ReHo in the medial prefrontal cortex and anterior insula. Significant differences in ReHo between the two bands were found in fusiform gyrus and superior frontal gyrus (slow-4> slow-5), and in basal ganglia, parahippocampus, and dorsal middle prefrontal gyrus (slow-5> slow-4). Importantly, we identified significant interaction between frequency bands and groups in the inferior occipital gyrus and caudate body. This study demonstrates that ReHo changes in schizophrenia are widespread and frequency dependent.

Regional homogeneity changes in amnestic mild cognitive impairment patients

“…This was consistent with the results of previous studies [4,5,20]. More detailed correlations between cognitive impairment and regional spontaneous activity of aMCI patients in the resting-state fMRI studies should be further investigated.…”

“…To further investigate the effects of regional brain atrophy on ReHo, we calculated the regional atrophy index within each region showing significant between-group differences on ReHo [20]. We performed the voxel-based morphometry (VBM) analysis on the T1-weighted images using the toolbox in SPM8 (VBM8 http://dbm.neuro.uni-jena.de/vbm/).…”

“…It has been used in the studies of neurological and psychiatric diseases, including migraine [9], stroke [10], epilepsy [11], neuromyelitis optica [12], Parkinson's Disease [13], attention-deficit hyperactivity disorder [14], AD [4,15], aMCI [3], social anxiety disorder [16], panic disorder [17], blindness [18], depression [19] and schizophrenia [20].…”

Short-term effects of escitalopram on regional brain function in first-episode drug-naive patients with major depressive disorder assessed by resting-state functional magnetic resonance imaging

“…(We adopted the recommended neighborhood size of 26; In this way, ReHo can map the level of regional activity across the whole brain of an individual (Kiviniemi, 2008). This method has been successfully applied in studies of several psychiatric illnesses, such as schizophrenia (Yu et al 2013), depression (Yao et al 2009), attention deficit hyperactivity disorder (Cheng et al 2012) and Alzheimer's disease (AD; He et al 2007). The findings of these ReHo studies were essentially compatible with other R-fMRI studies (Liu et al 2008;Tomasi & Volkow, 2012;Zhao et al 2012;Tao et al 2013) of these illnesses, most of which used the functional connectivity method and examined the brain changes at the network level.…”

Females with schizophrenia have abnormal functional cortical connectivity in the gamma frequency during an auditory oddball task using magnetoencephalography

“…Schizophrenia patients showed smaller clusters of greater amplitude of low-frequency fluctuations in the caudate, including the frontal, temporal/insular regions, putamen, and hippocampus, in an fMRI study in a resting state [88]. A regional homogeneity (ReHo) method combined with resting-state fMRI showed that ReHo abnormalities in schizophrenia were frequency-dependent in the inferior occipital gyrus and caudate body, suggesting abnormality in brain oscillation [89]. These findings suggested that dysfunction in the caudate nucleus is involved in cortico-striatal functional connectivity.…”