Figure 1. Cortical neurons with Shank3 knockdown show a selective reduction of NMDAR-mediated ionic and synaptic currents. A, Representative Western blots of Shank3 in HEK293 cells transfected with full-length rat Shank3 (Shank3FL) or the N-terminal deleted, siRNA-resistant Shank3 construct (Shank3R) in the presence of Shank3 siRNA or a scrambled control siRNA. B, Top, Immunostaining of Shank3 in cortical cultures (DIV19–22) transfected with control siRNA, Shank3 siRNA, or Shank3 siRNA plus Shank3R. Bottom, Bar graphs (mean ±SEM) showing the density, size, and intensity of Shank3 clusters (red) in neurons (GFP-positive) with different transfections. *p < 0.01, ANOVA. C, Representative traces of NMDAR- or AMPAR-mediated ionic currents in cultured cortical neurons (DIV 21) transfected with control siRNA, Shank3 siRNA, or Shank3 siRNA plus Shank3R. Calibration: 200 pA, 0.5 s. D, Bar graph summary of the NMDAR- or AMPAR-current density in cortical cultures with different transfections. *p < 0.01, ANOVA. E, Representative traces of evoked NMDAR-EPSC and AMPAR-EPSC in cortical neurons (DIV 14–18) transfected with Shank3 siRNA or GFP alone. Calibration: 20 pA, 50 ms. F, Bar graphs showing the peak amplitude of evoked NMDAR-EPSC and AMPAR-EPSC in cortical cultures with different transfections. *p < 0.01, t test.