Moreover, neurotrophic factors, such as brain-derived neurotrophic factor and basic fibroblast growth factor, significantly decrease in both the cortex and striatum in old mice as compared with young mice after stroke, leading to impaired support to the neurons at risk of death from ischemia (Chen and Sun, 2007; Arumugam et al., 2010). The gene discussed is BDNF; the disease is ischemia.