Atrophy of Basal Forebrain Initiates with Tau Pathology in Individuals at Risk for Alzheimer's Disease

Evidence suggests that the basal forebrain (BF) cholinergic system degenerates early in the course of Alzheimer's disease (AD), likely due to the vulnerability of BF cholinergic neurons to tau pathology. However, it remains unclear whether the presence of tauopathy is the only requirement for initia...

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Bibliographic Details
Authors: Cantero, JL; Atienza, M; Lage, C; Zaborszky, L; Vilaplana, E; Lopez-Garcia, S; Pozueta, A; Rodriguez-Rodriguez, E; Blesa, R; Alcolea, D; Lleo, A; Sanchez-Juan, P; Fortea, J; Alzheimers Dis Neuroimaging Initia
Format: Article
Status:Published version
Publication date:2020
Country:España
Institution:Institut d’Investigació Biomèdica Sant Pau (IIB Sant Pau)
Repository:r-IIB SANT PAU. Repositorio Institucional de Producción Científica del Instituto de Investigación Biomédica Sant Pau
OAI Identifier:oai:iibsantpau.fundanetsuite.com:p1686
Online Access:https://iibsantpau.fundanetsuite.com/Publicaciones/ProdCientif/PublicacionFrw.aspx?id=1686
https://europepmc.org/articles/pmc8493660?pdf=render
Access Level:Open access
Keyword:basal forebrain
biomarkers
cholinergic system
magnetic resonance imaging
nucleus basalis Meynert
preclinical Alzheimer's disease
Description
Summary:Evidence suggests that the basal forebrain (BF) cholinergic system degenerates early in the course of Alzheimer's disease (AD), likely due to the vulnerability of BF cholinergic neurons to tau pathology. However, it remains unclear whether the presence of tauopathy is the only requirement for initiating the BF degeneration in asymptomatic subjects at risk for AD (AR-AD), and how BF structural deficits evolve from normal aging to preclinical and prodromal AD. Here, we provide human in vivo magnetic resonance imaging evidence supporting that abnormal cerebrospinal fluid levels of phosphorylated tau (T+) are selectively associated with bilateral volume loss of the nucleus basalis of Meynert (nbM, Ch4) in AR-AD individuals. Spreading of atrophy to medial septum and vertical limb of diagonal band Broca (Ch1-Ch2) occurred in both preclinical and prodromal AD. With the exception of A+, all groups revealed significant correlations between volume reduction of BF cholinergic compartments and atrophy of their innervated regions. Overall, these results support the central role played by tauopathy in instigating the nbM degeneration in AR-AD individuals and the necessary coexistence of both AD proteinopathies for spreading damage to larger BF territories, thus affecting the core of the BF cholinergic projection system.