Co-cultured macrophages prevent hypoxia-induced neuronal cell death <i>in vitro.</i>

<p><b>A</b>–<b>F:</b> NeuN staining was performed on control organotypic hippocampal cultures (control OHCs), OHCs subjected to oxygen-glucose deprivation (OGD) (hypoxia) or OHCs subjected to OGD and co-cultured with macrophages (hypoxia+macrophages). Low magnification views of hippocampal slices are shown in A, C and E. High magnification views of the dentate gyrus are shown in B, D and F. As compared to control hippocampal slices (A, B), neuron cell loss was demonstrated in oxygen/glucose-deprived OHCs (C, D) and was found to affect the dentate gyrus systematically. In contrast, oxygen/glucose-deprived OHCs that were co-cultured with macrophages appeared partially protected from OGD-induced neuron cell death. <b>G:</b> A quantitative analysis of neuron density was performed in the dentate gyrus by measuring the area covered by NeuN staining relative to the area analyzed. An arbitrary value of 100% was attributed to the measures obtained in control OHCs. Data showed a mean 35% ±8% neuron density relative to controls in oxygen/glucose-deprived OHCs (hypoxia) and that co-culture with macrophages (hypoxia+macrophages) allowed neuron density to reach 70% ±10% relative to controls (Mann-Whitney, n = 3 experiments in each group, ***: p<0.001).