AQP4 and bacterial meningitis: Finally, contributing to the malfunctioning of the glymphatic system, we observed during bacterial meningitis a detachment of the astrocytic end feet from the blood-brain barrier (BBB) vascular endothelium, which leads to the misplacement of aquaporin 4 (AQP4) water channels, which causes the interruption of exchange of between the CSF and the brain interstitial space.