Figure 5.

CYFIP1 Is Required for Correct Spine Morphology

(A) Dendritic spines are defective in ex vivo cortical neurons from Cyfip1^+/− mice. Cortical neurons were labeled with DiI by diolistic staining on brain slices. Panels show representative dendritic sections; scale bar represents 5 μm. Insets in the lower panel represent magnification of individual spines classified as mature (stubby and mushroom-like) and immature (long thin and filopodia). Scale bar represents 0.5 μm.

(B) Dendritic spine morphology in cortical neurons from WT (black) or Cyfip1^+/− (white) animals. Distribution of spines as percentage is shown (n = 282 WT; n = 310 Cyfip1^+/−; χ² test, ^∗p < 0.05). Bars represent mean ± SEM.

(C) Mean spine length in WT and Cyfip1^+/− neurons (Student’s t test, ^∗∗∗p < 0.001). Bars represent mean ± SEM.

(D) Dendritic spines are altered in cultured cortical neurons silenced for Cyfip1. Outline of dendritic shafts from DIV14 primary cortical neurons transfected with scrambled, two Cyfip1 shRNAs (shRNA 319, 315), or shRNA 315 cotransfected with RNAi-resistant CYFIP1 WT, mutΔ, mutH, or mutE. Panels show representative dendritic sections; scale bar represents 5 μm.

(E) Dendritic spine morphology of neurons shown in (D), expressed as percentage of mature (in black, stubby + mushroom-like) and immature (in white, long thin + filopodia) spines (at least ten neurons/condition, χ² test, ^∗∗∗p < 0.001).

(F) Upper panel: mean spine length of neurons shown in (D) (one-way ANOVA with Bonferroni correction, ^∗∗∗p < 0.001). Lower panel: Cumulative probability plots for mean spine length. Bars represent mean ± SEM.

See also Figure S5.