Studies on the Cholinergic Differentiation Factor for Cultured Sympathetic Neurons

Abstract

Over the past 10 years, it has been shown that individual neurons of neural crest origin are plastic with respect to transmitter phenotype (Patterson 1978, Le Douarin 1980). Transplantation studies in chick-quail chimeras have shown that the population of neural crest cells can become either noradrenergic or cholinergic, depending on the embryonic environment in which they are placed (Le Douarin 1980). The transmitter phenotype of the neurons can be switched even after the cells cease migrating and form ganglia (Le Douarin et al. 1978). Moreover, studies under the more defined conditions of cell culture have shown that the alteration of transmitter phenotype is not due to a selection of certain neural crest subpopulations for survival but a change in transmitter metabolism at the single-cell level (Reichardt and Patterson 1977, Potter et al. 1981).