BDNF and Alzheimer disease: The mechanisms by which elevated levelsof PAI-1 have been implicatedin the pathogenesis of Alzheimer involve the accumulation of β-amyloiddue to reduced tPA/plasmin production and reduced neurogenesis andloss of synaptic connections in the brain due to reduced BDNF signaling.In this study, we analyzed PAI-1 and BDNF serum levels and the PAI-1/BDNFratio in patients with Alzheimer’s dementia, in individualswith amnestic mild cognitive impairment, and controls.