Via the Technology Review, a short overview of recent research into regenerative medicine for neurodegeneration: "We know new cells are made and go to the site of new injury, whether it's stroke or Parkinson's or Alzheimer's. One strategy to treat neurodegeneration is to boost this response. ... Recent studies have shown that many types of drugs - antidepressants, cholesterol-lowering drugs, even Viagra - spur growth of new neurons in the brain ... scientists can use these compounds to figure out how certain drugs trigger neurogenesis and then try to find or design compounds that boost new cell growth even more effectively ... scientists found that a drug similar to those used to treat Parkinson's disease can spur growth of new neurons in the brain area damaged in the disease. Scientists found that treated animals had twice the number of proliferating neurons as control animals, and that many of the newly generated cells appeared to develop into dopamine neurons. In addition, the animals showed an 80 percent improvement in their motor ability."