Intrinsic oscillations of auditory networks in schizophrenia and bipolar disorder

Abstract

Objective: Several types of evidence have shown that auditory networks are dysfunctional in schizophrenia (Sch) and bipolar disorders (BD). Auditory cortices show abnormalities in hallucinations or during remission. This study aimed to assess resting-state connectivity of auditory cortices in Sch and BD. Method: Patients with BD-1 (n=28), BD-2 (n=21), Sch (n=30), and healthy controls (HC, n=30) were enrolled into the study. A 3 Tesla whole-body magnetic resonance imaging (MRI) system with a 32-channel phase-array head coil was used to acquire the MRI data. T1-weighted anatomical and gradient-echo based Echoplanar Imaging sequences were used. MATLAB and Freesurfer software packages were used for data analyses. Connectivity alterations within the auditory network guided our further seedbased connectivity analysis. Results: The left angular gyrus volume was decreased in Sch and BD-2 groups. The supramarginal gyrus had hyperconnectivity with the medial prefrontal cortices and decreased connectivity with the medial superior temporal gyrus (STG) in the BD-1 and BD-2 groups. The left superior temporal sulcus (STS) had increased connectivity with the bilateral posterior cingulate cortex in BD-1 and BD-2 and increased connectivity with the dorsal prefrontal cortices in the Sch group. The STS had increased connectivity with the medial STG in the BD-1 and Sch groups, whereas connectivity decreased in the BD-2 group. Conclusion: These findings suggest that functional connectivity of resting-state networks are altered in BD and Sch. Auditory network alterations may predispose to dysfunctional auditory information processing. Further studies are needed to determine the relationship between symptoms and auditory network dysfunction.