Journal of Neuroscience, Vol 8, 1001-1015, Copyright © 1988 by Society for Neuroscience
Migration and differentiation of neural crest and ventral neural tube cells in vitro: implications for in vitro and in vivo studies of the neural crest
JF Loring, DL Barker and CA Erickson
Department of Zoology, University of California, Davis 95616.
During vertebrate development, neural crest cells migrate from the dorsal
neural tube and give rise to pigment cells and most peripheral ganglia. To
study these complex processes it is helpful to make use of in vitro
techniques, but the transient and morphologically ill-defined nature of
neural crest cells makes it difficult to isolate a pure population of
undifferentiated cells. We have used several established techniques to
obtain neural crest-containing cultures from quail embryos and have
compared their subsequent differentiation. We confirm earlier reports of
neural crest cell differentiation in vitro into pigment cells and
catecholamine-containing neurons. However, our results strongly suggest
that the 5-HT-containing cells that develop in outgrowths from thoracic
neural tube explants are not neural crest cells. Instead, these cells arise
from ventral neural tube precursors that normally give rise to a population
of serotonergic neurons in the spinal cord and, in vitro, migrate from the
neural tube. Therefore, results based on previously accepted operational
definitions of neural crest cells may not be valid and should be
reexamined. Furthermore, the demonstration that cells from the ventral
(non-neural crest) part of the neural tube migrate in vitro suggests that
the same phenomenon may occur in vivo. We propose that the embryonic
"neural trough," as well as the neural crest, may contribute to the PNS of
vertebrates.