Naturally occurring cell death (NOCD) has been recognized for many years as a critical phase in the development of the nervous system (Hamburger and Levi-Montalcini, 1949; Oppenheim, 1991). During this process, immature neurons undergo an active process of cell death, probably because they receive insufficient quantities of trophic factors from their target cells. Active cell death implies a molecular program of cellular-self-destruction and is therefore often called programmed cell death (PCD) (Schwartz and Osborne, 1993). Diverse morphological types of PCD have been described, with apoptosis being the most commonly encountered (Kerr et al., 1972; Clarke, 1990). After the NOCD period, neuronal apoptosis is considered to be pathological and is found to be implicated in clinical outcomes, such as Alzheimer’s disease, Parkinson’s disease, or Huntington’s disease. It is also observed in acute stresses, such as ischemia.