As we age our brains become less adept at making new nerve connections or repairing broken ones. A CIRM-funded team at the University of California, Irvine, restored this youthful ability, called nerve plasticity, to adult mice by transplanting embryonic nerve cells.
Specifically, they worked with mice that had a form of blurred vision known as amblyopia and the nerve cells they transplanted were ones that produce the nerve signal GABA. That amino acid helps regulate many aspects of brain function, including vision. The transplanted nerve cells allowed the brain to rewire itself and make connections that were missing and causing the poor vision. Several weeks later, the mice started to see normally.
The researchers transplanted the new cells directly into the visual cortex where the new nerve connections were needed. The mice had developed amblyopia, like humans, because the proper nerve connections failed to develop during a critical period when they were young. At the point in time that the transplanted embryonic cells would be going through that same critical period is when the researchers saw the improvement in vision for the adult mice. In a press release picked up at MedMerits.com the leader of the team, Sonil Gandhi explained what they saw:
“These experiments make clear that developmental mechanisms located within these GABA cells control the timing of the critical period.”
Gandhi added that the work should open up the possibility of trying to use GABA cell transplants to retrain the brain after injury or to repair congenital defects.
The news site NewsMax wrote an article on the research adding a bit more analysis.