ABSTRACT
The clarification of mechanisms of developmental cell death may provide hints in the prevention of pathological neuronal death. The execution phase of cell death has been extensively characterized; however, events that occur prior to this phase are less well understood. Previous studies have suggested that terminally differentiated neurons induced to die in various experimental paradigms may be making an abortive attempt to reenter the cell cycle. We have examined this process in postmitotic motoneurons and dorsal root ganglia sensory neurons in the developing chick embryo in vitro and in vivo. An examination of the programmed cell death of postmitotic motoneurons does not implicate a role for cell cycle-related proteins. We did, however, observe a decrease in the amount of cell death in dorsal root ganglion cells of embryos treated with cell cycle inhibitors. These results indicate that upstream initiators of the neuronal cell death pathway vary between phenotypes.
