β-AMYLOID ACCUMULATION IN RELATION TO FUNCTIONAL CONNECTIVITY IN HEALTHY AGING PEOPLE: A LONGITUDINAL STUDY

Abstract

It has been proposed that β-Amyloid (Aβ) deposition in the human brain occurs while individuals are still cognitively normal. In autopsy and post-mortem studies, Aβ neuropathology was found in cognitively normal older people emphasizing the importance of normal aging research to detect these early Aβ depositions. However, how Aβ pathology influences the brain’s functional organization remains unclear. This study employed resting-state functional MRI and PIB positron emission tomography in a longitudinal healthy aging dataset and examined the spatial distribution of Aβ accumulation and its influence on the brain functional organization. We first found the trans-modal regions had faster Aβ accumulation with aging and slower functional organization degeneration, especially in hub regions. Second, the Aβ accumulation rate manifested differently in the trans-modal and unimodal networks regarding the brain functional organization degeneration. Third, the Aβ accumulation rate propagates through strong FC in the trans-modal networks while through weak FC in the unimodal networks.