Neuroscience is the study of the nervous system, which includes the brain and the spinal cord. It's a broad term encompassing numerous, more specific disciplines, including cognitive, clinical, and developmental neuroscience.
Researchers at the German Cancer Research Center in Heidelberg have discovered a particular molecule, named Dickkopf-1 or Dkk1, that seems to have a positive effect on cognition in the elderly. Typically, as humans (and rats) age, they produce fewer neurons, which inhibits cognitive abilities. But when Dkk1 is blocked, older rats tested just as well as younger rats on memory and recognition tests.