Altered resting-state functional connectivity and anatomical connectivity of hippocampus in schizophrenia

Spontaneous brain activity observed with functional magnetic resonance imaging as a potential biomarker in neuropsychiatric disorders

“…And both the decreased rsFCs within the DMN, especially altered conenctivities in the MPFC, and reduced integrity of the anterior cingulate bundle were found in chronic schizophrenia patients (Camchong et al 2009). The convergent fMRI and DTI findings support the internal consistency between the anatomical and functional connectivity, but direct correlations between fMRI and DTI measures were not found (Zhou et al 2008) or not investigated (Camchong et al 2009). In order to directly measure the spatial correlation between the structural connectivity and functional connectivity, Skudlarski et al (2010) used the similarities in the connectivity matrices obtained from the DTI and rs-fMRI to investigate the spatial coherence from the global, regional, voxel and network level.…”

“…Considering that the hippocampus has been implicated as participating in the pathophysiology of schizophrenia, the FC pattern of the anterior hippocampus was also investigated. In patients with schizophrenia, the bilateral hippocampi showed reduced rsFCs to some regions which have been reported to be involved in episodic memory, such as the PCC, the extrastriate cortex, the MPFC, and the parahippocampal gyrus, which may reflect the disconnectivity within a neural network related to the anterior hippocampus in schizophrenia (Zhou et al 2008).…”

“…In patients with schizophrenia, a reduced hippocampal rsFC and a reduced integrity of the fornix (the major fiber bundle linking the hippocampus and other brain regions) was found in the same patients (Zhou et al 2008). And both the decreased rsFCs within the DMN, especially altered conenctivities in the MPFC, and reduced integrity of the anterior cingulate bundle were found in chronic schizophrenia patients (Camchong et al 2009).…”

“…The method strongly depends on prior knowledge about the related disorders. In published studies, the ROI was selected according to the researchers' interest and outlined by hand (Wang et al 2006b;Allen et al 2007;Zhou et al 2008) selected by software Zhou et al 2007a) or identified by known coordinates (Bluhm et al 2007;Castellanos et al 2008) This subjectivity in ROI selection has lead to slight differences in the anatomical location of the ROIs, which led to differences in the ROI FC patterns, as we noted in the case of the discrepancy in the hippocampal FC in AD (Wang et al 2006b;Allen et al 2007). More deeply, the differences in the anatomical location of the ROIs may be a reflective of the variability in the neuronal composition of the ROIs.…”

“…In schizophrenia, aberrant rsFCs within the DMN are found, but the main difference is that the strength of the rsFCs are abnormally increased in patients. By analyzing the clinical correlates of the strength of the rsFC, the rsFCs associated with the component regions of the DMN are found to vary with positive symptoms measured by different clinical scales (Bluhm et al 2007;Garrity et al 2007;Zhou et al 2008). The positive symptom-dependent correlation of the component region in the DMN suggests that functional dysconnectivity in the DMN may be a reflection of an impaired self-monitoring function in schizophrenia, which could lead to positive symptoms such as hallucinations and delusions (Williamson 2007).…”