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

Cereb Cortex. 2020 Apr 14;30(4):2083-2098. doi: 10.1093/cercor/bhz224.


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.

Keywords: basal forebrain; biomarkers, cholinergic system; magnetic resonance imaging; nucleus basalis Meynert; preclinical Alzheimer’s disease.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Alzheimer Disease / cerebrospinal fluid*
  • Alzheimer Disease / diagnostic imaging*
  • Atrophy
  • Basal Forebrain / diagnostic imaging*
  • Biomarkers / cerebrospinal fluid
  • Cross-Sectional Studies
  • Female
  • Humans
  • Magnetic Resonance Imaging / methods
  • Male
  • Middle Aged
  • Risk Factors
  • tau Proteins / cerebrospinal fluid*


  • Biomarkers
  • MAPT protein, human
  • tau Proteins