Effects of transwell co-cultures on EP1 antagonist-mediated neuroprotection. Transwells containing either mixed cultures, neuron-depleted mixed cultures, astrocytes or microglia cultures were co-cultured with neuronal-enriched cultures for 48 hours prior to treatment with vehicle (veh) or the EP1 antagonist SC51089 (SC) and subsequent challenge with NMDA (average [NMDA] = 15 μM for neuronal-enriched cultures and astrocyte-containing cultures and 16 μM for cultures with transwells containing mixed cultures, neuron-depleated mixed cultures and microglia). Neuronal viability was assessed 20 hours after NMDA in each culture paradigm (as outlined in Figure 1) and compared to neuronal-enriched cultures without transwells (first two bars in each set). The composition of the transwell cultures are marked above the bars. The relative amount of neuroprotection was assessed with two different amounts of NMDA-induced excitotoxicity 20% survival (A) and 10% survival for (B). For 10% survival the average [NMDA] = 12 μM for neuronal-enriched cultures and astrocyte-containing cultures and 18 μM for cultures with transwells containing mixed cultures, neuron-depleated mixed cultures and microglia. Each set is the average (+ SEM) of four independent experiments. Protection by SC in neuronal-enriched cultures with and without astrocytes was highly significant (P < 0.001 by ANOVA Tukey-Kramer multiple comparison test). A line is included in the bar to show the additional amount of survival conferred by addition of the EP1 antagonist.