Figure 3.

Genetic deletions of NR2A and NR2B subunits have differential effects on NMDA-induced neuronal apoptosis. Cultured mouse cortical neurons from NR2A^−/− embryos or NR2B^−/− embryos and WT littermate control mice were treated with NMDA (50 μm plus 10 μm glycine) for 20 min. Neurons were stained with Hoechst-33342 20 h after NMDA treatments and examined by microscopy. Apoptosis was quantified as the percentage of cells demonstrating cromatin condensation/fragmentation. NMDA-induced apoptosis was significantly reduced by genetic deletion of NR2B (B), but not NR2A (A), subunit (n = 4–6 tissue culture wells with >150 cells counted in each group). *p < 0.05 and **p < 0.01, compared with nontreated WT control; ^#p < 0.05, compared with NMDA-treated WT group. KO, Knock-out.