I always wondered why drugs such as cocaine which causes you to produce dopamine could not be modified to safe levels and prescribed to these people who are basically not able to produce it on their own. Who knows, maybe it is...
Anyways, good news that maybe people will soon stop looking to aborted fetuses for stem cells.
THe neurotransmitter in Parkinson's is replaced with L Dopa (often combined with an enzyme to make it last longer, in Sinemet). However, after awhile it stops working or you get side effects.
The movie "awakenings" shows how it was used for a severe form of Parkinson's disease; in normal parkinson's disease, people stay well for five or ten years before it stops working. That's why all the interest in stem cells
Interestingly enough, an earlier experiment using aborted baby's brain cells ended up with overgrowth and dyskinesias caused by too MUCH of the neurotransmitter: and this is harder to treat.
I can't see how someone else's stem cells couldn't become a hazard. It seems like there would be no way to stop them if they suddenly decided that your body was the foreign object and made antibodies against you. Your own stem cells wouldn't do that ---it still seems like there could be some risk but your body at least already has mechanisms for regulating them.