During a lecture at the Howard Hughes Medical Institute, it was mentioned that there are over 5,000 different classes of neuronal cells. This coincides with an earlier article at http://www.sciencedaily.com/releases...1127123927.htm that talks about the need for stem cells to have the proper instruction set for the damaged neuronal cells they are needed to replace.

During this lecture, it was also mentioned that when the axons attempt to connect to dendrites, they also must have the proper instructions in the form of a "may connect" or "may not connect." This binary 'yes/no' system is used throughout the brain. This is a big part of the slow nature of brain development. The axons must go through billions of these trial and error attempts to attach to the correct dendrites. Each neuron has up to 10,000 axons so this is obviously a very complex network.

*Stem cell therapy is being researched to rescue damaged neurons. It is hoped to help with brain injuries. It has show to be effective in newly damaged mouse and human brain cells in-vitro (lab test tube). If this therapy is reproducible in humans,* If this stem cell therapy is reproducible, it appears that it would require the stem cell rescue therapy be applied in the first day or so after the concussion.

As most PCS symptoms are not evident during those first few days, it would be problematic to get a concussion sufferer this level of intensive and likely expensive treatment during the first days' window of opportunity.

This would also require an inventory of pluripotent stem cells sitting on the shelf ready for transplant.

This rescue therapy may be worthwhile for comatose head injury patients. The risk/benefit/cost ratio will be much better. I wonder if the steroids used to prevent brain swelling and the drugs that maintain coma are compatible with these stems cells? If there are open wounds and/or surgery issues, then antibiotics may also come into play. **