Amyloid plaques in postmortem human cortex correlated with the proportion of microglia that were activated, not with microglial numbers. Tau pathology and cognitive decline come later.
Frail people may be more likely to have Aβ plaques and neurofibrillary tangles; when they do, they are more likely to have dementia. Physical activity correlated with better global cognition, regardless of brain pathology.
In neurons derived from FTD patients, microtubules distort the nucleus, warping its normally rounded membrane and disrupting communication with the cytoplasm.
A leaky blood-brain barrier in the hippocampus correlated with cognitive impairment, independently of other vascular risk factors or Alzheimer’s pathology.