Fig. 1. Overexpression of p53 induces neurotoxicity in rat hippocampal pyramidal neurons. Hippocampal cultures were infected at 7 DIV, using 100 MOI of each virus. A, Western blots showing overexpression of p53, p21, and HΔpRb after 48 hr of infection. Hippocampal cultures were infected on 7 DIV, using 100 MOI of each virus. Similar results were found in three separate experiments. B, Time course plot of cell viability after Adp53, Adp21, Adβgal, or AdHΔpRb infection of hippocampal pyramidal neuron cultures. Results represent the mean ± SEM of 12 coverslips. ***p < 0.001 versus control conditions (no virus); ANOVA and Tukey’s test. C,D, Pictures showing colocalization of human p53 expression (C) and chromatin fragmentation measured using Hoechst 33342 (D, n> 200 cells). E, F, Cultures stained using the TUNEL technique illustrating the degree of double-stranded DNA breaks in control cultures (E) and 48 hr after Adp53 infection (F). Scale bar, 20 μm.