University of California, Berkeley, biologists have found a signal that keeps stem cells alive in the adult brain, providing a focus for scientists looking for ways to re-grow or re-seed stem cells in the brain to allow injured areas to repair themselves.
The researchers discovered in fruit flies that keeping the insulin receptor revved up in the brain prevents the die-off of neural stem cells that occurs when most regions of the brain mature into their adult forms. Whether the same technique will work in humans is unknown, but the UC Berkeley team hopes to find out.
"This work doesn't point the way to taking an adult who has already lost stem cells and bringing them back mysteriously, but it suggests what mechanisms might be operating to get rid of them in the first place," said Iswar K. Hariharan, UC Berkeley professor of molecular and cell biology. "Plus, if you were able to introduce neural stem cells into an adult brain, this suggests what kinds of mechanisms you might need to have in place to keep them alive."
Hariharan noted that other researchers have gotten neural stem cells to persist by blocking genes that cause them to die. Yet this alone does not produce healthy, normal-looking neural stem cells that can make mature neurons. The UC Berkeley team's new finding shows that it also is necessary to provide an insulin-like signal. If stopping neural stem cell death is analogous to taking your foot off the brake, then providing an insulin-like signal is like stepping on the gas, he said. Both are essential.
Hariharan, post-doctoral researcher Sarah E. Siegrist and their colleagues published their findings today (Thursday, March 25) in the online version of the journal Current Biology. Their report will appear in the journal's April 13 print edition.
Most areas of the adult mammalian brain and fruit fly brain are devoid of neural stem cells, the only cells able to generate full-fledged neurons. Presum
|Contact: Robert Sanders|
University of California - Berkeley