NLRP3 and major depressive disorder: Animal experiments have shown that the NLRP3 initiation state in the brain of aged mice may be associated with isoflurane-induced hippocampal inflammation and cognitive impairment,[23] and inhibition of NLRP3 signaling can improve POCD in aged mice.[24] For depression, NLRP3 activation regulates caspase-1 activation, promotes maturation of IL-1β and IL-18 in microglia, and activates microglia.[25]