The present invention relates to a simplified process, which is shorter in time, for propagation of proliferating cells, such as e.g. progenitor or stem cells, by means of a biphasic culturing system having a differentiation supporting component and a proliferation supporting component, and to the use of the stem cell cultures obtained in this way for cell therapy purposes. The present invention invention describes a method, which is highly efficient to prime stem or progenitor cells to differentiation using non-attachment matrices and differentiation supporting component. The cells produced therefrom may be used to treat a variety of neurodegenerative disorders.