APP expression acts to potentiate and accelerate tau toxicity in the LEC. (a) Mapping group × age interactions revealed that age-dependent worsening of relative CBV (rCBV) was increased in the MEC of EC-APP mice compared with their controls (left) and increased in the LEC of EC-Tau mice compared with their controls (right). (b) Mapping a group × age interaction revealed age-dependent worsening of CBV in the LEC and PRC (left), and the PPC (right), of EC-APP/Tau mice compared with EC-APP and EC-Tau mice. Line graph illustrations of the group × age interactions in the LEC (upper graph) and the PPC (lower graph) of EC-APP/Tau (red) mice compared with EC-APP and EC-Tau mice (blue). *P < 0.05, **P < 0.001; #F1,83 = 14.346, P = 0.0003; ##F1,83 = 4.829, P = 0.031. Data are presented as mean ± s.e.m.