Electron Microscopic and Histochemical Examination of Oral Epithelial-Mesenchymal Interaction (Programmed Cell Death)

Oral ectodermal cells that appear to be programmed to die as part of normal embryonic development were studied histochemically and electron microscopically. Cytochemical changes were noted in these and neighboring cells at about the time that key events in their differentiation have been said to occur. It was hypothesized that the transitory appearance of alkaline phosphatase in subjacent mesenchyme and decreased respiration in the ectoderm are crucial events in the differentiation of this cell type.