Brain, Heal Thyself

Caltech neuroscientists have found a way to stimulate the growth of neural stem cells in the adult brain up to sixfold—cells that might then be used to repair it. According to Paul Patterson, the Biaggini Professor of Biological Sciences, future work may find ways to direct these stem cells—which have the ability to turn into other types of brain cells as they mature—to replace cells that die in disorders such as Parkinson’s and Alzheimer’s diseases and multiple sclerosis. “Basically, what my colleague Sylvian Bauer did was take a protein called leukemia inhibitory factor, or LIF, and inject it into the brains of adult mice,” Patterson explains. “The results show that you can stimulate the subventricular zone to produce a much larger pool of adult neural stem cells.” (Bauer, the lead author of the paper describing the work that appeared in the November 15 issue of the Journal of Neuroscience, was a postdoc in Patterson’s lab at the time.)

“The brains of patients with neurodegenerative diseases show evidence that their neural stem cells do attempt to replace dying cells,” says Patterson. “However, their contribution is very limited. Our approach may overcome this, and using one’s own cells avoids the problems of the brain rejecting the transplanted cells.” The next step is to see if these cells can be directed to replace cells in mice with brains that are damaged in ways similar to those of humans with Parkinson’s, Alzheimer’s, and multiple sclerosis.

This development in no way renders the use of embryonic stem cells obsolete, or argues against further research with embryonic stem cells, Patterson says. Embryonic stem cells have the potential to become any cell in the body, whereas this process uses adult neural stem cells for brain disorders only. —RT