Nerve Growth Factor

Abstract

(Second of Three Parts)Development of the Sympathetic Nervous SystemDetailed reviews of this subject have recently been published^{9, 56} and should be consulted for additional facts and for a discussion of the development of preganglionic neurons. The general plan of sympathetic-nervous-system development in chicks and mammals is quite similar, but the earliest appearance of catecholamines in embryonic neuroblasts and the rate of maturation of the system vary with the species.⁵⁶ Sympathetic development begins with migration of neural-crest cells ventrad into the mesenchyme between the neural tube and the myotome.³² These cells first take up residence in two columns dorsolateral to . . .