Morphological Similarity Network Based On Divergence And Application In Schizophrenia

Schizophrenia is a severely disabling psychiatric disorder characterized by hallucinations,delusions,loss of initiative,and cognitive dysfunction.Gray matter atrophy,such as reduced gray matter volume and abnormal cortical folding patterns,has been found to exist in the cerebral cortex of patients with schizophrenia.It was shown that the cortical gray matter is damaged in a covariant pattern and the diffusion pattern of gray matter atrophy in multiple regions formed a complete morphological network,which provides a research basis for understanding morphological similarity changes.As an important representation of brain structure,whether the morphological connections between different regions of the cerebral cortex are abnormal in schizophrenia and whether the morphological changes are related to impaired functional connectivity in schizophrenia are still unclear and need to be further investigated.In this thesis,we investigate the similarity connectivity abnormalities in schizophrenia patients with impaired morphology and their interaction with functional connectivity by constructing morphological similarity networks.The first study in this thesis was based on the grey matter volume similarity network to investigate the abnormalities of grey matter volume similarity connections in schizophrenia patients.The results showed that the global efficiency of the grey matter volume similarity network was reduced in schizophrenia patients,and the topological properties appeared higher locally mainly in the basal ganglia.Meanwhile,the two abnormal subnetworks we found predicted the duration of disease in schizophrenia patients.This study reveals the presence of topological abnormalities in the grey matter volume similarity network between brain regions in schizophrenia patients and further confirms that abnormal grey matter volume similarity network connectivity may serve as an objective measure to characterize the duration of disease in schizophrenia patients.To investigate the similarities and differences in the different representation of morphological similarity networks,the second study in the thesis construct sulcus depth similarity brain network to further analysis.The results demonstrated that sulcus depth similarity network in schizophrenia patients also appeared as two subnetworks,involving nodes similar to grey matter volume but with opposite abnormal trends,and only predicted negative symptoms.The study suggests that the different morphological networks are inconsistently characterized and may be related to different clinical factors in schizophrenia patients.In the third study,a multiplex network is integrated with morphological similarity network and functional connectivity to explore the interaction between abnormal gray matter atrophy connectivity and brain functional connectivity disorder in schizophrenia patients.The results suggested that the global community spatial distribution pattern was identical in schizophrenia and healthy controls,while the local community distribution was abnormal and the subcutaneous nuclei were reorganized in communities.the nodal overlapping strength was increased in the schizophrenia group,and this abnormal morphological-functional overlapping pattern was predictive of schizophrenia-related clinical factors,and this abnormal overlapping connectivity was found to be associated with gene overexpression by partial least squares analysis.The multiplex network provides a new insight into the interaction between morphological-functional connectome.It reveals the clinical symptoms are correlate with abnormal patterns of overlapping strength in morphological similarity and functional connectivity in schizophrenia and provides a biological explanation for morphological-functional interactions.In summary,this thesis investigates the analysis of morphological similarity networks with different morphological measures and proposes an analysis of morphological-functional multiplex network to describe abnormalities from morphological similarity network in schizophrenia and the interaction of morphological similarity network and functional connectivity,which demonstrates the clinical relevance of morphological similarity connections and their interaction with functional connectivity and provides a new directions for the biological interpretation underlying the abnormalities of morphological similarity network in schizophrenia.