Journal of Neuroscience, Vol 8, 806-813, Copyright © 1988 by Society for Neuroscience
High-affinity uptake of noradrenaline in quail dorsal root ganglion cells that express tyrosine hydroxylase immunoreactivity in vitro
ZG Xue and J Smith
Institut d'Embryologie du CNRS, Nogent-sur-Marne, France.
During embryonic life, avian sensory ganglia contain cells with the
potential to express, under appropriate experimental conditions, a number
of properties characteristic of autonomic sympathetic neurons. Thus, cells
capable of synthesizing noradrenaline (NA) from tyrosine differentiate when
dorsal root ganglia (DRG) from 10-15 d embryonic quail are grown in culture
(Xue et al., 1985a, b). In the present study, we show that cultures of DRG
from 10 d embryos can take up 3H-NA by a high-affinity (Km = 1.0 microM),
temperature-dependent process that can be inhibited by desmethylimipramine.
By means of combined immunocytochemistry and autoradiography, it was
demonstrated that the majority (70-80%) of the tyrosine hydroxylase
(TH)-immunoreactive cells that developed in the cultures possessed a
transport system for NA. Catecholamine (CA) uptake also occurred in a
small, but relatively constant, number of TH-negative cells, but was absent
from substance P- containing neurons. In contrast to TH, which appears only
after 3-4 d in vitro, cells capable of taking up NA with high affinity were
found in DRG cultures after only a few hours, and a small number (less than
0.5% of the total cell population) was detected in freshly removed,
uncultured ganglia. Such cells did not react with antibodies directed
against substance P or neurofilament proteins. We conclude that autonomic
precursors are identifiable in a subset of non-neuronal DRG cells, prior to
full expression of a noradrenergic phenotype, by their possession of a
high-affinity uptake system for CA.