Immunofluorescence microscopy is then used to evaluate tight-junction proteins (occludin, claudin-5 and zona-occluden-1 (ZO-1)), AQP4 water channels and activated microglia to understand which BBB immune cell changes may be involved with peripheral and neuroinflammatory mechanisms in Alzheimer’s disease pathogenesis. Here, TJP1 is linked to Alzheimer disease.