CPP was induced in adult rats with saline or cocaine at 20 mg/kg. After each afternoon conditioning session, rats received intra-core infusion of anisomycin or vehicle. Immediately after the test, brains were processed for DeS analysis. CPP scores were expressed as the means ± S.E.M. (A) (Two-way ANOVA, F_{cocaine(1,30)} = 6.364, p = 0.18; F_{anisomycin(1,30)} = 2.851, p = 0.101; F_{cocaine × anisomycin} = 6.364, p<0.05). Total DeS density was expressed as spines/µm (mean ± S.E.M.) in MSN from the NAcc core (B) (Two-way ANOVA, F_{cocaine(1,30)} = 36.03, p<0.001; F_{anisomycin(1,30)} = 14.86, p<0.001; F_{cocaine × anisomycin} = 15.51, p<0.001) and shell (D) (Two- way ANOVA, F_{cocaine(1,30)} = 48.46, p<0.001; F_{anisomycin(1,30)} = 39.31, p<0.001; F_{cocaine × anisomycin} = 37.72, p<0.001). Density of mushroom, stubby, branched or thin spines was expressed as spines/µm (mean ± S.E.M.) in MSN from the NAcc core (C) (Two-way ANOVA mushroom, F_{cocaine(1,30)} = 2.636, p = 0.114; F_{anisomycin(1,30)} = 2.096, p = 0.158; F_{cocaine × anisomycin} = 3.405, p = 0.074; Two-way ANOVA stubby, F_{cocaine(1,30)} = 5.852, p<0.05; F_{anisomycin(1,30)} = 9.828, p<0.05; F_{cocaine × anisomycin} = 6.994, p<0.05; Two-way ANOVA branched, F_{cocaine(1,30)} = 0.081, p = 0.776; F_{anisomycin(1,30)} = 0.626, p = 0.434; F_{cocaine × anisomycin} = 0.419, p = 0.522; Two-way ANOVA thin, F_{cocaine(1,30)} = 33.43, p<0.001; F_{anisomycin(1,30)} = 13.75, p<0.001; F_{cocaine × anisomycin} = 14.33, p<0.001) and shell (E) (Two-way ANOVA mushroom, F_{cocaine(1,30)} = 0.574, p = 0.454; F_{anisomycin(1,30)} = 2.215, p = 0.147; F_{cocaine × anisomycin} = 0.03, p = 0.861; Two-way ANOVA stubby, F_{cocaine(1,30)} = 0.944, p = 0.338; F_{anisomycin(1,30)} = 0.62, p = 0.426; F_{cocaine × anisomycin} = 0.004, p = 0.949; Two-way ANOVA branched, F_{cocaine(1,30)} = 0.942, p = 0.339; F_{anisomycin(1,30)} = 2.319, p = 0.138; F_{cocaine × anisomycin} = 3.028, p = 0.092; Two-way ANOVA thin, F_{cocaine(1,30)} = 44.43, p<0.001; F_{anisomycin(1,30)} = 30.71, p<0.001; F_{cocaine × anisomycin} = 32.67, p<0.001). * p<0.05; *** p<0.001; n.s. (not significant) vs Saline + vehicle group; # p<0.05; ### p<0.001 vs Cocaine + vehicle group, Bonferroni post-hoc test, n = 7 to 9 animals/group.