Stratoulias, VassilisRuiz, RocíoKanatani, ShigeakiOsman, Ahmed M.Keane, LilyArmengol, Jose A.Rodríguez-Moreno, AntonioMurgoci, Adriana-NataliaGarcía-Domínguez, IreneAlonso-Bellido, IsabelGonzález Ibáñez, FernandoPicard, KatherineVázquez-Cabrera, GuillermoPosada-Pérez, MercedesVernoux, NathalieTejera, DarioGrabert, KathleenCheray, MathildeGonzález-Rodríguez, PatriciaTremblay, Marie-ÈveBlomgren, KlasVenero, Jose L.Joseph, BertrandBrodin, DavidCao, YangPérez-Villegas, Eva M.Martínez-Gallego, IreneLastra-Romero, AlejandroAvila-Cariño, JavierAiravaara, MikkoUhlén, PerHeneka, Michael T.2024-01-252024-01-2520232023Stratoulias, V., Ruiz, R., Kanatani, S., Osman, A. M., Keane, L., Armengol, J. A., ... Joseph, B. (2023). ARG1-expressing microglia show a distinct molecular signature and modulate postnatal development and function of the mouse brain. Nature Neuroscience, 26, 1008-1020. https://doi.org/10.1038/s41593-023-01326-3https://doi.org/10.1038/s41593-023-01326-3http://hdl.handle.net/1828/15893We would like to thank S. Vazquez and B. Ben-Azu for technical support. We are grateful to P.C. Nahirney for the use of a transmission electron microscope and B. Gowen for technical assistance.Molecular diversity of microglia, the resident immune cells in the CNS, is reported. Whether microglial subsets characterized by the expression of specific proteins constitute subtypes with distinct functions has not been fully elucidated. Here we describe a microglial subtype expressing the enzyme arginase-1 (ARG1; that is, ARG1+ microglia) that is found predominantly in the basal forebrain and ventral striatum during early postnatal mouse development. ARG1+ microglia are enriched in phagocytic inclusions and exhibit a distinct molecular signature, including upregulation of genes such as Apoe, Clec7a, Igf1, Lgals3 and Mgl2, compared to ARG1– microglia. Microglial-specific knockdown of Arg1 results in deficient cholinergic innervation and impaired dendritic spine maturation in the hippocampus where cholinergic neurons project, which in turn results in impaired long-term potentiation and cognitive behavioral deficiencies in female mice. Our results expand on microglia diversity and provide insights into microglia subtype-specific functions.enARG1-expressing microglia show a distinct molecular signature and modulate postnatal development and function of the mouse brainArticleDivision of Medical SciencesSchool of Medical Sciences