The objective of this proposal is to investigate a number of important processes which occur during the development of neurons within the enteric nervous system. Consequently, the proposal consists of three projects, each of which overlapp by utilizing chimeric embryos and/or organotypic culture methods in conjunction with immunohistochemistry. Project 1 will investigate neural crest cell proliferation within chick- quail chimeric embryos, using antibodies directed against quail cells, and the mitotic cell marker BrdU. Results will provide information concerning the location and time period when crest cell proliferation occurs. Project 2 will investigate the potential role of chemoattraction in the gut by utilizing genetic mutant mice, lacking certain receptors and ligands. Segments of gut from these animals will be cultured in association with quail ganglia to DETERMINE if the quail cells are chemically attracted in the absence of ligands/receptors. In project 3, the development of interstitial cells of Cajal will be examined in aneural gut to DETERMINE if these network forming cells are capable of developing their normal phenotype in the absence of neurons with which they are closely associated. Although the time course for neural colonization of the gut is well established, the results obtained from these projects will contribute new information concerning the migration and proliferation of developing neurons and their effect on other cells.
In the course of this project, the candidate will utilize familiar techniques in addition to embryological methods, such as the chick-quail marker system, chorioallantoic membrane grafting and organotypic culture methods to address important developmental issues within the enteric nervous system. The utilization of these powerful tools will significantly add to the knowledge of the candidate in his field of research, while also broadening his technical base.