Contributions of placodal and neural crest cells to avian cranial peripheral ganglia
Article first published online: 3 FEB 2005
Copyright © 1983 Wiley-Liss, Inc.
American Journal of Anatomy
Volume 166, Issue 4, pages 445–468, April 1983
How to Cite
D'amico-Martel, A. and Noden, D. M. (1983), Contributions of placodal and neural crest cells to avian cranial peripheral ganglia. Am. J. Anat., 166: 445–468. doi: 10.1002/aja.1001660406
- Issue published online: 3 FEB 2005
- Article first published online: 3 FEB 2005
- Manuscript Accepted: 26 OCT 1982
- Manuscript Received: 26 JUL 1982
The method of embryonic tissue transplantation was used to confirm the dual origin of avian cranial sensory ganglia, to map precise locations of the anlagen of these sensory neurons, and to identify placodal and neural crest-derived neurons within ganglia. Segments of neural crest or strips of presumptive placodal ectoderm were excised from chick embryos and replaced with homologous tissues from quail embryos, whose cells contain a heterochromatin marker. Placode-derived neurons associated with cranial nerves V, VII, IX, and X are located distal to crest-derived neurons. The generally larger, embryonic placodal neurons are found in the distal portions of both lobes of the trigeminal ganglion, and in the geniculate, petrosal and nodose ganglia. Crest-derived neurons are found in the proximal trigeminal ganglion and in the combined proximal ganglion of cranial nerves IX and X. Neurons in the vestibular and acoustic ganglia of cranial nerve VIII derive from placodal ectoderm with the exception of a few neural crest-derived neurons localized to regions within the vestibular ganglion. Schwann sheath cells and satellite cells associated with all these ganglia originate from neural crest. The ganglionic anlagen are arranged in cranial to caudal sequence from the level of the mesencephalon through the third somite. Presumptive placodal ectoderm for the VIIIth, the Vth, and the VIIth, IXth, and Xth ganglia are located in a medial to lateral fashion during early stages of development reflecting, respectively, the dorsolateral, intermediate, and epibranchial positions of these neurogenic placodes.