Sensitivity of oligodendrocytes from COX-2 knockout mice to excitotoxic death and protection with COX-2 inhibitors. (A) Oligodendrocytes from COX-2 knockout mice are more resistant to KA-induced excitotoxicity. Dispersed oligodendrocyte cultures were prepared from wild-type (WT), heterozygous COX-2 knockout (COX-2 +/-) and homozygous COX-2 knockout (COX-2 -/-) and treated with KA. Surviving cells were scored 24 hours after KA treatment. This is the average of two independent experiments. (B) The COX-2 inhibitor CAY 10404 does not protect COX-2 knockout oligodendrocytes from KA-induced death. Dispersed oligodendrocyte cultures were prepared from COX-2 -/- mice and treated with KA in the presence or absence of CAY 10404 (10 uM). Viability was assessed 24 hours after treatment with KA. There was no significant increase in the number of surviving oligodendrocytes in the CAY 10404-treated group. Error bars are SEM.