Deletion of the Cupidin Cdc42-binding domain influences dendritic spine morphology in hippocampal neurons. (A) GFP fluorescence images of primary cultured rat hippocampal neurons infected with the recombinant adenovirus vector containing GFP-CPD or GFP-CPDΔ191–230 (= GFP-Δ191–230). (B) Dendrites expressing GFP-CPD or GFP-CPDΔ191–230 (= GFP-Δ191–230) fluorescence (green) were outlined by staining with DiI (red). White arrows indicate representative puncta of GFP-CPDΔ191–230 (= GFP-Δ191–230) located in dendritic shafts. The ratios of puncta present in either spine heads or dendritic shafts per total puncta in dendrites were quantified. *, p < 0.01; * *, p < 0.001. (C) Spine morphologies of neurons expressing GFP, GFP-CPD, or GFP-CPDΔ191–230 (= GFP-Δ191–230) were arbitrarily categorized into five types (mushroom-, filopodium-, stubby-, twin head-, and odd-shaped types) as indicated in the inset; each population (%) is shown in the pie charts. The graph shows the number of spines present in a 10-μm length of secondary dendrites of these neurons. *, p < 0.05. Bars: (A) 20 μm, (B and C) 5 μm.