Coexpression of somatostatin-like immunoreactivity and catecholaminergic properties in neural crest derivatives: comodulation of peptidergic and adrenergic differentiation in cultured neural crest.

In the avian embryo, somatostatin-like immunoreactivity (SLI) and adrenergic characteristics appear virtually simultaneously in the developing sympathetic nervous system and adrenal medulla. We have used double-labeling techniques to show that both properties coexist in the same cells. In the quail, not only do all somatostatin-containing cells in the adrenosympathetic system exhibit tyrosine hydroxylase immunoreactivity and possess catecholamines (CA), but this coexistence of the peptidergic and adrenergic phenotypes is already present very early in ontogeny. However, not all adrenergic cells express SLI. The development of sympathoadrenal precursors can be followed in vitro. Adrenergic precursor cells, obtained from the migrating neural crest, differentiate in culture into neuron-like cells that contain SLI and CA. This coexpression can be regulated by the same factors. For instance, corticosterone and progesterone increase SLI content and CA production in the neural crest cell cultures. The ontogeny of the autonomic lineage is discussed in the light of these results.