The development of the chromaffin cell lineage from the neural crest

Chromaffin cells are neuroendocrine cells, which are highly specialized for the synthesis and release of multiple hormones. Like sympathetic neurons, which are essential, inter alia, for neural control of vascular tone, they are derivatives of the neural crest, a transient structure at the dorsal surface of the embryonic neural tube. Chromaffin cells and sympathetic neurons have many features in common, but are also distinct in several respects. This review provides a summary of similarities and differences regarding the development of chromaffin cells and sympathetic neurons, viewed from molecular and morphological perspectives. Two major, still not finally settled issues, are whether (1) the two related cell types arise from one common or two separate cell lineages of delaminating neural crest cells, (2) in the former case when does lineage segregation occur, and what are the molecules underlying their phenotypic diversification.