Illustrations of PCD alterations in spinal cord of transgenic mutant SOD1 mice. (a) Photomicrograph of definitely apoptotic cells found in the anterior horn of an end-stage transgenic SOD1^G93A mouse. The arrow shows several typical round chromatin clumps. (b) Western blot analysis of spinal cord extracts, demonstrating the relocation of Bax from the cytosol (top) to the mitochondria (bottom) over the course of the disease. (c) Coincidental changes of cytochrome c in the opposite direction. (d) Later in the disease, effector caspases such as caspase-7 are activated. 1M (AS): 1 month, asymptomatic stage; 2M (AS): 2 months, asymptomatic stage; 3M (BS): 3 months, beginning of symptoms; 5M (ES): 5 months, end stage; Non-TG: nontransgenic littermates. Modified from ref. 63.