Neurons were washed three times with BSS (balanced salt solution; 25 mM Tris, 120 mM NaCl, 15 mM glucose, 5.4 mM KCl, 1.8 mM CaCl2, 0.8 mM MgCl2, pH 7). After treating the neurons with 200 µM NMDA (Sigma) or only DMSO for 6 hours, cells were washed three times with BSS again and processed for RT-qPCR, ChIP and FAIRE analysis.