Holtzman hopes his work may someday have major implications for people, in the form of therapies to grow new neurons to compensate for brain damage.
"One of the most interesting discoveries in neuroscience and cognitive science is that new nerve cells, neurons, can be formed in some brain regions in adult higher-order vertebrates, including primates," says Timothy Nyberg, a Rochester undergraduate who joined Holtzman in the research. Neuroscientists know, for instance, that adult humans can produce limited numbers of new neurons related to the sense of taste and smell, as well as in the hippocampus, a brain region involved in memory and spatial learning. New neurons grow in other animals as well: Learning to store food engenders brain growth in birds, even doubling the number of hippocampal cells, and in lizards, if the hippocampus is removed, it can grow back -- and skills lost return as if by magic.
It's Holtzman's theory that what holds for snakes, lizards, and birds may also hold for their evolutionary descendants -- humans. If he and his colleagues come to understand how to control the mechanisms that govern neurogenesis in other animals, it could offer new therapies for the treatment of people afflicted by brain damage -- whether from accidents, strokes, or diseases like Alzheimer's or Parkinson's. The work could also help to better pin down the as-yet fuzzy notion that babies who grow up in more stimulating environments develop more robust brains.
Holtzman and Nyberg were joined in the research by Anita
Stone, a former research assistant; Terrence Harris, now a
physician at Washington University; Guillermo Aranguren, now a
graduate student at the University of Texas at Tyler; and
Elizabeth Bostock, a physician at the University of Rochester.
The research was sponsored by the National Institutes of Health's
National Center for Research
Contact: Tom Rickey
University of Rochester