AQP4 and dementia: Mitochondrial health in astrocytic end‐feet is closely tied to perivascular channel expression; from the human brain samples of the idiopathic normal pressure hydrocephalus (dementia subtype), Hasan‐Olive et al. (2019) found pathological mitochondria at end‐feet strongly correlated with reduced perivascular AQP4 and increased astrogliosis (Hasan‐Olive et al. 2019).