AQP4 and brain ischemia: In line with data demonstrating the critical role of edema in stroke-associated morbidity and mortality, several studies have shown that post-ischemic edema in the brain is associated with brain fluid homeostasis and strictly regulated by aquaporin 4 (AQP4) channels, which are mainly expressed in perivascular astrocytic end-feet, and targeting AQP4 could be a useful therapeutic approach for treating brain ischemia and edema [46,47,48,49].