Reduction of spine density in orbitofrontal cortex of Dlgap2−/−mice. (A) Representative pictures of spine density from Dlgap2+/+ (WT) and Dlgap2−/− (KO) mice. (B) Spine density was lower in Dlgap2−/− (KO) mice. Scale bar: 2.5 μm. Data are presented as mean ± standard error of the mean. n = 64 to 70 segments of dendrites from four Dlgap2+/+ (WT) and four Dlgap2−/− (KO) mice. *P < 0.05 from a two-tailed t-test. KO, knockout; WT, wild type.