PDGFRB and Cognitive impairment: Our observations are also compatible with previous studies in which PDGFR-β immunoreactivity and soluble PDGFR-β were used to assess pericytes [35], particularly the earlier observations by Montagne et al. [34] showing that blood-brain barrier (BBB) breakdown in the CA1 region of the hippocampus worsened with mild cognitive impairment (MCI) and correlated with injury to BBB-associated pericyte.