MAPT and Alzheimer disease: More recently, an assessment of NVU changes in post-mortem hippocampal and cortical tissues of AD patients revealed a progressive decrease in pericyte coverage which correlated with the Braak stages of AD severity and both Aβ and p-tau pathology.88 Although the evidence is not sufficient to support a causal relationship, the data suggest that loss of pericytes might precede and mediate accumulation of Aβ and p-tau.