Following repeated cocaine administration (15 mg/kg, , i.p.; 10 days), spine density was measured in the NAc of βAdd KO mice and their WT siblings. Density (spine number/um) of A) Total, B) mushroom, C) thin, and D) stubby spines was measured using NeuronStudio. There was a significant increase in the number of mushroom and thin spines in the NAc of βAdd WT and KO mice following cocaine treatment (*, p ≤ 0.05 post hoc analysis, Tukey's-HSD).