Both TNFα production and TNFR1 are required for poly(I:C)-induced preOL death in mixed glial cultures. Mixed glial cultures derived from WT, TNF-/- or TNFR1-/- were stimulated with vehicle (sterile PBS; 5 μl/ml), poly(I:C) (50 μg/ml), or LPS (1.0 μg/ml) for 48 h. A, D:TNFα production as determined by ELISA. Results are means ± SEM of 3 independent experiments. B-C; E-F:PreOL viability as determined by O4+ cell counting. Both LPS and poly(I:C) caused preOL toxicity in cultures derived from WT B6129 (B) and WT C57BL/6 (E) mice, but had no effect in cultures derived from TNF-/- (C) or TNFR1-/- (F) mice. Results are means ± SEM of 3 independent experiments for each mouse strain. *, p < 0.05, **, p < 0.01, ***, p < 0.001.