IL4 and Cognitive impairment: Cognitive impairment associated with hippocampal cell loss and microglial activation, along with increased levels of interleukin-1β (IL-1β), tumor necrosis factor α (TNFα), and nitric oxide (NO), was observed in murine brains after i.p. and i.c.v. administration of LPS, while interleukin-4 (IL-4) and interleukin-10 (IL-10) were reduced [23,24,25].