(Invitrogen), 1 μg ml−1 laminin and 20 ng ml−1 FGF2 (Invitrogen)). To obtain mature neurons, neural progenitor cells were differentiated in DMEM/F12 supplemented with 1× N2, 1× B27, 20 ng ml−1 BDNF (Peprotech), 1 mM dibutyrl-cyclicAMP (Sigma), 200 nM ascorbic acid (Sigma), 1 μg ml−1 laminin and 620 ng ml−1 Wnt3a (R&D) for 3 weeks. Wnt3a was removed after 3 weeks. All cells used in the present study were verified as free from mycoplasma contamination.
