Primary culture of neural precursors from the ovine central nervous system(CNS)

The present study demonstrates that bipotential neural precursors isolated from an early developmental stage of the sheep embryo nervous system can be maintained in vitro in an undifferentiated state for a long period. These precursors multiplied under the action of epidermal growth factor and basic fibroblast growth factor and formed free-floating aggregates of nestin-imm unoreactive cells, called neurospheres. These precursors can undergo predom inantly neural or glial differentiation according to the culture conditions . Medium supplemented with foetal calf serum mainly favoured cell different iation predominantly into astrocytes, whereas the defined SATO medium favou red neuronal differentiation. Using various immunomarkers of neurones and a stroglial cells, we described the course of differentiation of neuronal and astroglial cells in different culture conditions. The ability to grow neur al precursors from common laboratory animals has been useful for studying t he cellular and molecular mechanisms underlying the development of the cent ral nervous system. Furthermore, neural progenitors are already being used for in vivo cell therapy in various neurodegenerative disorders. The ovine species is a well-known model for prion diseases, since scrapie is endemic in most countries and has been studied for a long time. In this respect, th e availability of ovine neural precursors will add a new perspective to the study of the pathogenicity of prion diseases. (C) 2001 Elsevier Science B. V. All rights reserved.