Stem Cells
One of the faster moving areas of biological research over the last few years has been associated with stem cells. Many of the controversies associated with this area arose because at one time it was believed only embryos could provide sufficient numbers of “pluripotent” stem cells to meet the needs of researchers. (Pluripotent stem cells have the ability to develop into any kind of body cell.) In recent years researchers have learned how to extract stem cells from adult organs and cultivate them in the lab to produce other kinds of stem cell that have the potential to be used to treat disease, so reducing the need for pluripotent stem cells in these areas of research.
The use of stem cells for neurological treatments is a very challenging area of research as the environment of the nervous system poses a number of unique problems. Infusing nerve stem cells into the bloodstream does not get them into the nervous system as structures such as the nerve sheaths and meninges form a barrier separating the nervous system from the bloodstream. Experimentation on rats has shown that it is necessary to inject stem cells directly into the nervous system if they are to have any effect at all. However, some neurones are amongst the largest cells in the body, some being well over a meter long so, how do you encourage a nerve stem cell to grow to this size after you implant it into the nervous system? Another challenge is in how stem cells could be used to replace dead neurones and correctly connect the correct parts of the brain or spinal cord to the correct muscles without creating a spaghetti of wrong connections?
