Effect of activation of resident microglia on cell death in hippocampal slices. (A) Hippocampal slices, after culture for 14 days, were treated with LPS (10μg/ml) and IFN-γ (100Units/ml) for 5 days to activate resident microglial cells. (B) The microglia population in 12 day old hippocampal slice cultures was expanded by treatment with GM-CSF (10 ng/ml) for three days, followed by activation with LPS/IFN-γ treatment (LPS: 10 μg/ml; INF-γ: 100 Units/ml) for 5 days. At the end of the indicated treatment period, cell viability in hippocampal slices was determined based on propidium iodide (PI) uptake. *p<0.05 from WT; #p<0.05 from WT (vehicle), $p<0.05 from CD36−/− (vehicle) and WT (LPS/IFN-γ+GM-CSF). n= 30–36 slices in each group from 5 sets of separate experiments.