Now here's a novel approach!
Excerpt:
Researchers at Yale University say they took cells from the lining of human wombs and injected them into mice with brain damage.
The damaged brains resembled those with Parkinson's disease, which causes tremors as the brain loses the ability to produce dopamine.

The scientists were able to create healthy nerve cells using endometrial cells taken from nine women who didn't have Parkinson's.

Source: http://mystateline.com/fulltext-news/?nxd_id=159495

I will bet that someone is reading my mind already. As gross as it sounds, if they were usable, I know that the endometrial cellsl are those sloughed off each month by women. That would certainly provide an ample supply if they could be used.

Peg