Ouabain-induced ultrastructual features of hybrid cell death in LN229 cells. Electron microscopy was applied to examine the ultrastructual features of ouabain damaged glioblastoma cells. The lower panel is magnified images. Control cells showed intact plasma membranes, intact mitochondrial (arrows) and other organelles. Ouabain exposure (24 hrs) resulted in apparent necrotic changes such as breakdown of the plasma membrane, cytoplasmic swelling, appearance of large and empty vacuoles (arrow head), which is possibly an indication of autophagic activity. There were also signs of apoptotic pathology such as fragmented and shrinking mitochondria surrounded by the intact membrane (thick arrows), and acondensed/fragmented nucleus (*). Note that there was nuclear shrinkage in the absence of cell shrinkage, which is another sign of hybrid cell death.