SOD1 and amyotrophic lateral sclerosis: In the spinal cord of mutant SOD1 mice, mitochondria dysfunction occurs during the pre-symptomatic phase of disease [132,133,134,135,136,137] immediately before the onset of motoneuron degeneration [135]; this indicates that mitochondria dysfunction cannot be considered a secondary event associated with the disease state but rather is a key player in initiating the events leading to motoneuron loss in ALS.