Intrinsic connectivity of the human brain provides scaffold for tau aggregation in clinical variants of Alzheimer’s disease
Joseph Therriault, Tharick A. Pascoal, Mélissa Savard, Sulantha Mathotaarachchi, Andréa Lessa Benedet, Mira Chamoun, Cécile Tissot, Firoza Z Lussier, Nesrine Rahmouni, Jenna Stevenson, Muhammad Naveed Iqbal Qureshi, Min Su Kang, Émilie Thomas, Paolo Vitali, Jean‐Paul Soucy, Gassan Massarweh, Paramita Saha‐Chaudhuri, Serge Gauthier, Pedro Rosa‐Neto
Abstract
Alzheimer's disease (AD) phenotypes might result from differences in selective vulnerability. Evidence from preclinical models suggests that tau pathology has cell-to-cell propagation properties. Therefore, here, we tested the cell-to-cell propagation framework in the amnestic, visuospatial, language, and behavioral/dysexecutive phenotypes of AD. We report that each AD phenotype is associated with a distinct network-specific pattern of tau aggregation, where tau aggregation is concentrated in brain network hubs. In all AD phenotypes, regional tau load could be predicted by connectivity patterns of the human brain. Furthermore, regions with greater connectivity displayed similar rates of longitudinal tau accumulation in an independent cohort. Connectivity-based tau deposition was not restricted to a specific vulnerable network but was rather a general property of brain organization, linking selective vulnerability and transneuronal spreading models of neurodegeneration. Together, this study indicates that intrinsic brain connectivity provides a framework for tau aggregation across diverse phenotypic manifestations of AD.