Furthermore, while in the brain of sham control animals with a functioning glymphatic system, AQP4 expression is homogeneously expressed along the area between the astrocytic end feet and BBB vascular endothelium, in the brain of meningitis-affected rats in which the glymphatic system is malfunctioning, AQP4 expression is focal on astrocytic cells and far from any colocalization with the BBB endothelium (Fig. 2E). This evidence concerns the gene AQP4 and meningitis.