Thus, current literature suggests that apoptosis and necrosis often coexist
in adult tissues during injury or degeneration and that a full continuum of
morphological changes is often observed between apoptosis and necrosis.
4,11,12
The observed changes must be adequately described for the particular
experimental paradigm in order to define for given time points the mode
of cell death and injury. The major changes to be observed include nuclear
morphology and cytoplasmic morphology, organelle integrity (particularly
mitochondria), and membrane integrity. An impartial inventory of these
changes for a reasonable sample of the cells under consideration, of control
tissue, and at reasonable time intervals is necessary for considering apoptotic
mechanisms of cell death. Adequate demonstration of these features requires
consistently and well fixed and prepared material. This chapter will present
an overview of how to prepare and to analyze nervous system tissue by
transmission electron microscopy for mechanisms of cell injury and death.