IN-VITRO PATTERN-FORMATION DURING NEUROGENESIS IN NEUROECTODERMAL PROGENITOR CELLS IMMORTALIZED BY P53-DEFICIENCY

In vitro neural differentiation was induced in a p53-deficient immorta lized neuroectodermal progenitor cell line, NE-4C, by treatment with r etinoic acid [K. Schlett and E. Madarasz (1997) J. Neurosci. Res. 47, 405-416]. Rearrangement of nestin filaments was an early marker of neu ron-formation. The increase in neurofilament protein content was accom panied by a decrease in the expression of nestin filaments in induced precursors. Cells with astroglial features appeared with a delay of 4- 5 days compared to the appearence of neurons. Future neurons were sort ed out from the substrate-attached population of apparently non-induce d cells. The sorting out of future neurons resembled the separation of neural precursors in vivo. The continuous changes in the shape and al so in the position of the cells resulted in the formation of character istic morphological patterns. On the basis of morphological changes, f ive characteristic stages of ill vitro neural differentiation were dis tinguished. The analysis of the morphological changes revealed that ce ll-to-cell interactions played an essential role in the cell fare deci sion made by induced precursors. Our observations indicate that the NE -4C cell line can serve as an in vitro model to investigate some early steps of neurogenesis. (C) 1997 ISDN.