KCNJ10 and major depressive disorder: They showed that overexpression (gain-of-function) of astrocytic Kir4.1 channels increased neuronal bursts in the habenula and produced depression-like behaviors (i.e., immobility in a forced swim test and reduced sucrose preference), whereas expressional knockdown (loss-of-function) of Kir4.1 channels in the habenula decreased bursting and rescued depression-like behaviors.