Confocal study showed that peripheral blood-derived monocytes are more efficient in phagocytosis of tau oligomers than primary microglia. Confocal cross-section analyses of cells showed higher number of tau oligomers engulfed by macrophages as by BV2 microglial cells. Micrographs show tau oligomers positive TIB67 macrophages non-treated (A) or treated with LPS (B). The pictures demonstrate that almost all macrophages engulfed oligomeric tau. Primary microglia phagocytosing tau oligomers in the presence or absence of LPS treatment are shown in panels (C) and (D). Primary cells showed higher ability to phagocyte tau oligomers after LPS stimulation. Scale bar: 20 μM. Abbreviations: μM, micrometer; LPS, lipopolysaccharide.