Hippocampal Resting State Functional Connectivity in Patients With Schizophrenia and Unaffected Family Members

The hippocampus is an important candidate region in the study of functional connectivity alterations in schizophrenia (SZ) given its role as a functional hub for multiple brain networks. Although studies have implicated the hippocampus in SZ, no studies have compared hippocampal functional connectivity in healthy participants, patients with SZ, and unaffected family members (UAFMs). Patients and UAFM likely share biomarkers associated with susceptibility to SZ; the study of UAFM may also reveal compensatory markers. Patients with SZ, UAFM, and healthy control (HC) participants underwent resting state magnetic resonance imagingty and completed the Wisconsin Card Sort Task (WCST) as a measure of general cognitive function. We compared functional coupling with a hippocampus seed across the three groups. SZ and UAFM groups shared reductions in connectivity between the hippocampus and the striatum relative to HC. We also identified a significant positive correlation between WCST errors and hippocampal-striatal connectivity in the UAFM group. Hippocampal-striatal rsFC may be associated with familial susceptibility to SZ and with subtle cognitive deficits in the UAFM of individuals with SZ.