Cultured neurons were treated twice with NMDA (20 μM for 3min) alone, NMDA plus a protein synthesis or transcription inhibitor, inhibitor alone, or vehicle-/mock-treated, and processed for immunocytochemistry after 2 hrs. Quantification of the effects of (A1) anisomycin (aniso), (A2) cycloheximide (CHX), or (B) actinomycin D (actino) on NMDA-induced changes in synapse density from neurons stained with GFP and synapsin. Data are averaged means of synapses from at least three biological samples. Values within bars represent sample sizes (# neurons). Error bars represent SEM. Significance from control (CTRL): * p < 0.05, *** p < 0.001.