Based on studies in various mouse models, including brain aging, AD, and mild traumatic brain injury [30,31,32], which found that glymphatic clearance malfunction is related to mislocalization of AQP4 caused by reactive astrogliosis, the glymphatic clearance ability among AQP4−/−/APP/PS1 mice, APP/PS1 mice, AQP4−/− mice, and wild-type (WT) mice was compared. Here, AQP4 is linked to Alzheimer disease.