Parkinson's patients suffer degeneration of certain neurons in an area of the brain called the substantia nigra that projects into the striatum, the researchers said. Many newborn cells in that area haven't been well-described because of limitations of methods used to characterize them.

A team from Cedars-Sinai Medical Center's Dunitz Neurosurgical Institute and Sweden's Lund University has engineered a virus to deliver a protein that glows green when exposed to blue light. That, said the scientists, revealed no neurons are formed and most of the cells appear to be glial, or structural, cells.

To determine if newborn cells could be manipulated to generate neurons, the researchers used two genes -- neurogenin2 and noggin -- both of which are involved in the genesis of neurons. The scientists said neither gene had any effect on the ability of new striatal cells to form neurons but the insertion of noggin increased the number of oligodendrocytes cells that support neurons.

The study appeared as a cover article in the journal Neurobiology of Disease.