Aberrant Resting-State Functional Connectivity in the Default Mode Network in Pediatric Bipolar Disorder Patients with and without Psychotic Symptoms

Mood disorders/psychosis have been associated with dysfunctions in the default mode network(DMN).However,the relative contributions of DMN regions to state and trait disturbances in pediatric bipolar disorder(PBD)remain unclear.The aim of this study was to investigate the possible mechanisms of PBD through brain imaging and explore the influence of psychotic symptoms on functional alterations in PBD patients.Twenty-nine psychotic and 26 non-psychotic PBD patients,as well as 19 age-and sex-matched healthy controls underwent a restingstate functional MRI scan and the data were analyzed by independent component analysis.The DMN component from the fMRI data was extracted for each participant.Spearman's rank correlation analysis was performed between aberrant connectivity and clinical measurements.The results demonstrated that psychotic PBD was characterized by aberrant DMN connectivity in the anterior cingulate cortex/medial prefrontal cortex,bilateral caudate nucleus,bilateral angular gyri,and left middle temporal gyrus,while non-psychotic PBD was not,suggesting further impairment with the development of psychosis.In summary,we demonstrated unique impairment in DMN functional connectivity in the psychotic PBD group.These specific neuroanatomical abnormalities may shed light on the underlying pathophysiology and presentation of PBD.

Cell-type-specific genes associated with cortical structural abnormalities in pediatric bipolar disorder

Background Pediatric bipolar disorder(PBD)has been proven to be related to abnormal brain structural connectivity,but how the abnormalities in PBD correlate with gene expression is debated.Objective This study aims at identification of cell-type-specific gene modules based on cortical structural differences in PBD.Methods Morphometric similarity networks(MSN)were computed as a marker of interareal cortical connectivity based on MRI data from 102 participants(59 patients and 43 controls).Partial least squares(PLS)regression was used to calculate MSN differences related to transcriptomic data in AHBA.The biological processes and cortical cell types associated with this gene expression profile were determined by gene enrichment tools.Results MSN analysis results demonstrated differences of cortical structure between individuals diagnosed with PBD and healthy control participants.MSN differences were spatially correlated with the PBD-related weighted genes.The weighted genes were enriched for“trans-synaptic signaling”and“regulation of ion transport”,and showed significant specific expression in excitatory and inhibitory neurons.Conclusions This study identified the genes that contributed to structural network aberrations in PBD.It was found that transcriptional changes of excitatory and inhibitory neurons might be associated with abnormal brain structural connectivity in PBD.