Bar graph showing effects of plasma alone and in combination with PAR1 inhibitors on rat oligodendrocyte precursor cells (OPC) in culture. Cell death was measured by LDH release (optical density units; mean ± SEM). Plasma at 1/250 concentration added to the defined culture media was toxic to OPC as indicated by increased LDH release. There was no evidence for protection with SCH79797 and BMS20061 at any dose. Control values (no plasma) were significantly less than all groups (*p < 0.05) and there were no statistically significant differences between treatment groups (all comparisons p > 0.5).