The number of people of old age in western countries is growing, leading to an increased prevalence of degenerative brain diseases. These diseases are widely regarded as a limiting factor of quality of life in old age. The possibilities to maintain intellectual performance of the brain even in old age historically met with scepticism and diseases like Alzheimer's or Parkinson's disease were accepted as an inevitable consequence of aging. "The older, the sicker." However, during recent years new concepts were developed: The physiologic aging of the brain is distinct from diseases of the brain occurring during old age and pathogenesis of degenerative brain diseases is increasingly revealed. This results in novel, even neuroprotective, therapy strategies, implying that these diseases cannot only be seen as inevitable and incurable, but also as a target for prevention and symptomatic and causal therapy strategies.