Fig. 3. Expression of a stabilized form of ß-catenin promotes neuronal differentiation in the presence of Fgf2. (A) A model depicting the possible actions contributing to the increased neuronal population after activation of the canonical Wnt pathway. NP, neuronal progenitor; GP, glial progenitor; N, neuron; G, glia. (B) NPCs were infected with a retrovirus encoding either GFP alone (control) or both GFP and S33Y ß-catenin, and the percentage of TuJ1⁺ cells among GFP⁺ cells was determined at the indicated times after culture in the presence of Fgf2. Data are the mean±s.e.m. of values from six samples, and similar results were obtained in two independent experiments. (C) The percentage of HuC/D⁺ cells among GFP⁺ cells after culture for 2 days in the presence of Fgf2 was determined. Data are the mean±s.e.m. of values from eight samples, and similar results were obtained in three independent experiments.