Figure 9

Effect of estrogen treatment on glutamate-induced [Ca²⁺] _i and cell death. Neuronal cells were maintained for 6 days in conditions similar to those described under Figure 1. Cells were treated with various concentrations of 17β-E₂ and Δ⁸, 17β-E₂. After 24 hrs cells were loaded with 5 μM Fluo-3 AM and then treated with 200 μM glutamate. [Ca²⁺]_i measurements were made every 15 secs. Baseline levels of [Ca²⁺]_i were monitored for 60 secs prior to injection with 200 μM glutamate (indicated by glu). Following injection changes in [Ca²⁺]_i were monitored for an additional 120 secs. A. Representative trace of the effect of 5 μM 17β-E₂ on glutamate-induced [Ca²⁺]_i influx. Inset. Increase in percent protection with 5μM 17β-E₂ against 200 μM glutamate-induced cell death (same cells as those in which [Ca²⁺]_i measurements were made). B. Representative trace of the effect of Δ⁸, 17β-E₂ on glutamate-induced [Ca²⁺]_i influx. Inset. Increase in percent protection with 5 μM Δ⁸, 17β-E₂ against 200 μM glutamate-induced cell death (same cells as those in which [Ca²⁺]_i measurements were made). Each experiment was repeated a minimum of 6 times with 8 replicates of each treatment condition per experiment. Error bars represent SEM.