When cells in the brain are lost through disease or injury, neighbouring cells begin to divide and multiply.
Patients with Parkinson's disease suffer degeneration of certain neurons that reside in an area of the brain called the substantia nigra and project into the striatum, but only a few areas in the brain are able to produce new neurons.
Using a new technique, scientists used an engineered virus to deliver a protein that glows green when exposed to blue light (green fluorescent protein) into newborn cells of the striatum in rats with Parkinson's disease.
This revealed that no neurons are formed; most of the cells appear to be glial (structural) cells.
Further, the team studied whether the newborn cells could be manipulated to generate neurons
They delivered into the cells two genes (neurogenin2 and noggin) that are involved in the genesis of neurons.
Neither gene had any effect on the ability of newborn striatal cells to form new neurons, but it greatly increased the number of oligodendrocytes, cells that support neurons.
"These results may have great potential for studying the effects of viral gene delivery in the attempt to generate new cells for cell replacement therapy in neurodegenerative diseases or for brain repair after injury," said research scientist Dwain Morris-Irvin, Ph.D.
"The success of a 'self-repair' strategy depends on the continued growth of our understanding of complex signalling patterns governing the development of these newborn cells," he added.
The findings are reported in journal Neurobiology of Disease.