It is still uncertain however whether the absence of a classic apoptotic structure in selectively vulnerable neurons after ischemia is sufficient evidence to exclude the possibility that PCD mechanisms are operative. We conclude that neuronal death in the mature (adult) CNS after global ischemia exists as more than one temporally overlapping forms in hippocampus and cerebellum: necrosis or necrosis-apoptosis hybrids of selectively vulnerable neurons and classical apoptosis of granule neurons (149).