Journal of Neuroscience, Vol 7, 3749-3763, Copyright © 1987 by Society for Neuroscience
Phenotypic properties of catecholamine-positive cells that differentiate in avian neural crest cultures
DS Christie, ME Forbes and GD Maxwell
Department of Anatomy, University of Connecticut Health Center, Farmington 06032.
We have investigated several phenotypic features of the catecholamine-
positive (CA+) cell population that develops in quail neural crest
cultures. The number, spatial distribution, and morphology of CA+ and
tyrosine hydroxylase-positive (TH+) cells are similar at all ages examined,
suggesting that these 2 cell classes are identical. Neither CA+ nor TH+
cell bodies or processes were stained using antisera that recognize the 70
or 160 kDa subunits of chicken neurofilament protein. Other cell bodies and
fibers in the cultures (which were CA- and TH-) were stained with these
neurofilament antisera. The uptake and storage of 3H-norepinephrine by
neural crest cultures containing CA+ cells were inhibited in the presence
of desmethylimipramine and by incubation at 0 degrees C, but were
unaffected by normetanephrine. Overnight treatment with reserpine
eliminated histochemically detectable CA fluorescence from the cultures.
Chronic reserpine treatment from day 2 to 7 in vitro prevented the
appearance of CA+ cells, while normal numbers of TH+ and somatostatin-like
immunoreactive (SLI) cells developed. The number and light-microscopic
morphology of the CA+ cells that developed in these cultures were not
dramatically altered by either exogenous NGF or 6- hydroxydopamine. Using
the method of Grillo et al. (1974), we have demonstrated that the CA+ cells
observed in the light microscope corresponded to cells containing abundant
cytoplasmic granular vesicles (GV) characteristic of catecholamine storage
granules observed in other systems. The GV diameters were quite similar in
cells examined after 5, 7, 14, and 21 d in vitro. Most GV were 50-200 nm in
diameter and were distributed in a unimodal manner, with the observed modal
values in the range of 85-115 nm at the ages examined. The number of
GV/micron2 of cytoplasmic area remained quite constant at all ages
examined. These data, taken together with other available information,
suggest that the CA+ cells that differentiate in our neural crest cultures
resemble, in many respects, the small, intensely fluorescent cells found in
autonomic ganglia and extra-adrenal chromaffin tissue of many species. At
present, we do not know if the CA+ cells that differentiate in our neural
crest cultures are a stable endpoint of development or whether they are a
developmental intermediate in adrenergic differentiation that is normally
observed only transiently during the development of avian sympathetic
ganglia in vivo, but that can persist under our tissue culture conditions.