Once these stem cells are implanted, researchers feel they will regenerate and repair damaged nerve cells – namely the myelin sheath. The whole idea behind using stem cells comes from the fact that they are the body's raw materials. In other words, these are cells from which all other cells with specialized functions are made from.

In the body, stem cells divide to become daughter cells. The daughter cells will either become new stem cells – this is called self-renewal. When these cells divide and become specialized cells, this is called differentiation. What types of cells are these? Blood cells, brain cells, bone cells to name a few. Each has a specific function. No other cells in the body can make new cells depending on where they are in the body.

Stem cells come from several different places:

There is a controversy that surrounds the use of embryonic stem cells. These can only be gotten from early-stage embryos. These embryos come from eggs that are fertilized at in vitro fertilization clinics and never implanted in a woman's uterus. The embryos are from women who don't want them or either they don't need them. Usually women have donated the frozen embryos for research.

Adult stem cells – those which usually come from bone marrow – have been the subject of promising studies. There are several reasons why they aren't as sought after for research:

One good thing about them that scientist have found is that the adult stem cells are more adaptable than they first realized.

The therapy that replaces diseased or injured cells is called stem cell therapy. Most of us have heard of someone receiving an organ transplant. A non-functioning organ is replaced with a stronger more healthy one. Well, healthy stem cells are used to replace damaged cells. This process is called regenerative medicine.

The stem cells are grown directly in the lab. The researchers manipulate them so that they grow into a specific kind of cell – nerve cells in the case of MS. Did you know that stem cell transplants have been performed in the US since the 1960's? Well, they have. The procedure is called bone marrow transplants – and they use adult stem cells.

Are there any problems with embryonic stem cells? Yes.

Research is continuing in the field of stem cell transplant to refine the process. Adult stem cells may actually prove to be the best possible solution when it comes to diseases like multiple sclerosis. They're better accepted by people in general because they're less controversial. They're more predictable as well and what could be better in an unpredictable disease like MS?

Here's a video that may help to explain stem cell transplant for those of you who are visual learners. Check it out.