Fig. 2. Dyn3baa inhibits the development of normal neuronal morphology. Neuron morphology was quantified using two morphological criteria to distinguish between filopodia and spines. 18DIV Dyn3baa-expressing cells remained similar to 11DIV cultures with respect to protrusion length (A) and presence of a spine head (B), indicating that filopodia at 11DIV do not mature into spines by 18DIV in these neurons. By contrast, control neurons expressing Dyn3aaa-GFP or GFP exhibit this normal progression during development from filopodia to spines. Expression of the GTPase-deficient Dyn3baaKA-GFP did not affect the morphology of transfected neurons at 18DIV but did cause immature (11DIV) transfected neurons to contain morphologically mature spines. All error bars represent s.d.