Resting-state Functional Connectivity between Dorsolateral Prefrontal Cortex and Left Temporal Language-related Region in Unaffected First-degree Relatives of Schizophrenia Patients

According to the large body of literature data, patients with schizophrenia demonstrate altered (decreased) functional connectivity (FC) between the brain regions involved in executive functions and language (in particular, dorsolateral prefrontal cortex (DLPFC) and left temporal regions). However, the analysis of similar FC in the genetic risk group has not been done, although such data are significant for studying the neurobiological markers of schizophrenia, linked to the genetic architecture of the disorder (its traits or so-called endophenotypes). The aim of this study was to investigate whether FC between the DLPFC and left temporal language-related region was altered in unaffected first-degree relatives of patients with schizophrenia. First-degree unaffected relatives of patients with schizophrenia (12 subjects) and healthy individuals without family history of mental disorders (13 subjects) underwent resting-state functional magnetic resonance imaging at 3T Philips scanner. The FC between the regions of interest (left/right DLPFC, on the one hand, and left temporal region, on the other hand) was compared between groups as well as indexes of Verbal fluency and the Scale of Prodromal Symptoms (SOPS). As compared to controls, the relatives of patients with schizophrenia were characterized by increased FC between the left DLPFC and left temporal language-related region, although they did not differ in the other indexes, and there were no correlations between the indexes and FC. The findings might reflect some compensatory functional processes in unaffected first-degree relatives of schizophrenic patients.