Figure 5.

Calcineurin activity in primary cortical neurons after treatment with glutamate and/or 17β-estradiol in the presence of specific inhibitors of PP1, PP2A, or calcineurin. Primary cortical neurons were seeded in 100-mm dishes at a density of 500,000 cells/ml. A, Cells were treated simultaneously with 50 nm okadaic acid, 50 μm glutamate, and/or varying 100 nm 17β-estradiol. B, Cells were treated simultaneously with 200 nm PPI2, 50 μm glutamate, and/or 100 nm 17β-estradiol. C, Cells were treated simultaneously with 9 μm endothall, 50 μm glutamate, and/or 100 nm 17β-estradiol. D, Cells were treated simultaneously with 500 nm cyclosporine A (CsA), 50 μm glutamate, and/or 100 nm 17β-estradiol. Calcineurin activity was determined using a serine/threonine phosphatase activity assay (Promega) after 24 h exposure to the various compounds. All data were normalized to percent survival of vehicle-treated control. Depicted are mean ± sem for six independent experiments with triplicates per experiment. *, P < 0.05 vs. glutamate-treated group.