The brain of adult animals, including humans, sustained the ability to create new glial cells and neurons. This process is called postnatal neurogenesis. It is possible owing to the presence of neuronal stem cells in the neurogenic zones. The subependymal layer, a part of periventricular zone, demonstrates the highest intensity of neurogenesis. Ependymal cells, forming the external lining of the lateral ventricles, can also effectively differentiate into cells of the nervous system.

The population of stem/progenitor cells was selected from human cord blood non-hematopo- ietic (CD34 and CD45 negative) mononuclear fraction and was shown to attain neural features. Due to repeated expansion and selection of these cells in the presence of EGF we have established the first clonogenic, non-immortalized human umbilical cord blood neural stem cell like line (HUCB-NSC). This line can be maintained in culture at different developmental stages and their fate decisions can be experi- mentally manipulated in vitro by the presence of trophic factors, mitogenes and neuromorphogenes.