Excitation-inhibition balance abnormally shapes structure-function coupling of gray matter in Parkinson's disease

How neurobiological underpinnings regulate the heterogeneous expression of structural-functional connectivity coupling (SFC) in Parkinson's disease (PD) remains largely unknown. Our work examines changes in SFC in PD patients. The investigation was carried out to check the spatial distribution of SFC along the cyto-architectonic hierarchy. We related the excitation-inhibition balance (E/I ratio) to the expression of SFC in both PD and normal controls. The difference in the impact of the E/I ratio on SFC was compared between the groups. We found that widespread SFC increases occurred in PD. The distribution of SFC gradually increased along the cyto-architectonic hierarchy. A lower E/I ratio was found to be associated with more rigid SFC in both groups. The abilities of E/I ratio shaping SFC were heterogeneously disturbed in PD. Our work delivers a new framework to conceptualize structure-function relationships in PD patients, paving the way for an improved understanding of how neurobiological factors induce reorganization in the brain with PD invasion.