AQP4 and amyotrophic lateral sclerosis: In superoxide dismutase (SOD) mutant ALS mice, the overall level of astrocytic AQP4 was increased in the ventricornu, while AQP4 polarization in astrocytes was reduced as a result of localization from the terminal protrusions of swollen astrocytes to the cell membrane (Dai et al., 2017).