Stimulation of mixed glial cultures with poly(I:C) causes microglia activation and preOL cell death. Rat mixed glial cultures were stimulated with vehicle (sterile PBS; 5 μl/ml) or poly(I:C) (50 μg/ml) in BDM for 48 h. A:Immunocytochemical staining showing changes in microglia morphology (Iba-1; green) with process extensions closely associated with O4+ preOLs (red) in poly(I:C) treated cultures (arrows). Scale bar, 50 μm. B, C:Poly(I:C) stimulated cultures had elevated TNFα (B) and LDH (C) in culture supernatants as determined by ELISA and LDH assays respectively. D. O4+ cell viability was decreased following in poly(I:C) treatment. Results in Aare representative of 3 independent experiments. Results from B-Dare combined means ± SEM of 4-5 independent experiments.