Sustained loss of asymmetric synapses in layer II/III of PFC following PCP treatment. One-way ANOVA showed a significant effect of treatment group on synapse number (F(4, 23)=30.0, p<0.0001), indicated by asterisks. Scheffe's test showed that all time points (1, 2, 3, or 4 weeks) examined after PCP were not significantly different from each other, but all time points were significant decreased compared with the saline group (p<0.0001). There were 4–8 rats in each group.