neuronal differentiation, resuspended neural progenitor spheres were dissociated with Accutase at 37°C for 10 min and placed onto poly-D-lysine/laminin-coated coverslips in the neuronal culture medium, consisting of Neurobasal medium supplemented with 2 mM L-glutamine, B27, 10 ng ml−1 BDNF and 10 ng ml−1 GDNF. Half of the medium was replaced once a week during continuous culturing. For electrophysiological recordings, neural progenitors were plated on a confluent layer of rodent astrocytes as previously described21,34. These cultures exhibited similar neuronal densities and parallel cultures were used for recordings of different iPS cell lines in a blind fashion.
