MFG-E8 exerts neuroprotective effects in the presence of microglia. The effect of MFG-E8 treatment against oAβ toxicity in both neuron − microglia co-cultures (A) and neuronal cultures (B). Neurons were stained with an anti-MAP-2 antibody (green), microglia were stained with a Cy5-conjugated anti-CD11b antibody (blue), and oAβ was stained with an anti-4 G8 antibody (red). Scale bar = 50 μm. Untreated neuronal cultures and neuron − microglia cocultures (1:2 neurons to microglia) (cont; a). Five micromolar of oAβ induced neuronal loss in both neuronal and neuron–microglia cocultures (b). In the presence of microglia, MFG-E8 treatment induced neuroprotective effects in a dose-dependent manner (doses were 1 ng/mL (c), 10 ng/mL (d), 100 ng/mL (e) in (A)). On the other hand, MFG-E8 did not show any effects on oAβ-induced neurotoxicity, even at the highest dose (100 ng/mL; c in (B)). (C) Neuronal survival was estimated as the percentage of intact neurons in the treated sample relative to the untreated sample. The results are presented as the means with S.E.M. (n = 3), in which 10 randomly selected fields were analyzed. Significant differences compared to samples only treated with oAβ are noted. *: P <0.05, ***: P <0.001, (one-way ANOVA with Dunnett’s post-hoc test).