Alterations in the blood brain barrier in ageing cerebral cortex in relationship to Alzheimer-type pathology: a study in the MRC-CFAS population neuropathology cohort.

Impairment of the blood brain barrier (BBB) in human brain ageing and its relationship to Alzheimer-type pathology remains poorly defined. We have investigated the BBB in temporal cortex of brain donations from a population-representative sample of 92 participants from the Medical Research Council Cognitive Function and Ageing Study (MRC CFAS), a longitudinal study with a programme of brain donation. BBB alteration was investigated by immunohistochemistry to albumin and fibrinogen and to the tight junction proteins claudin-5, zonula occludens-1 (ZO-1) and occludin.