Mitochondrial dysfunction underlies cortical atrophy in prodromal synucleinopathies

Abstract

ABSTRACTIsolated rapid eye movement sleep behavior disorder (iRBD) is a prodromal synucleinopathy characterized by several changes including brain atrophy. The mechanisms underlying atrophy in iRBD are poorly understood. Here, we performed imaging transcriptomics and comprehensive spatial mapping in a multicentric cohort of 171 polysomnography-confirmed iRBD patients and 238 controls with T1-weighted MRI to investigate the gene expression patterns and the specific neurotransmitter, functional, cytoarchitectonic, and cognitive brain systems associated with cortical thinning in iRBD. We found that genes involved in mitochondrial function and macroautophagy were the strongest contributors to the thinning occurring in iRBD. Moreover, we demonstrated that thinning was constrained by the brain’s connectome and that it mapped onto specific networks involved in motor and planning functions. In contrast with thickness, changes in cortical surface area related to distinct gene and spatial mapping patterns. This study demonstrates that the development of atrophy in synucleinopathies is constrained by specific genes and networks.