Figure 2.

Role of AQP4 in brain water balance and extracellular space K ⁺ dynamics. A. Schematic showing site of AQP4 expression in brain and pathways for water movement out of brain. B. Improved survival of AQP4 knockout (−/−) mice following acute water intoxication. C. Delayed K⁺ clearance in brain following electrically induced seizure‐like neuroexcitation. Measurements done using K⁺‐sensitive microelectrodes inserted into brain cortex in live mice. Adapted from Binder et al 3 and Manley et al 38.