Sources of Stem Cells
Stem cell researchers are working to determine whether the use of stem cells could lead to better treatment or a cure for Parkinson's disease. Parkinson's symptoms occur when the brain cells that produce dopamine, an essential neurotransmitter (chemical that transmits nerve impulses), are damaged and information from the brain to the muscles is disrupted. Scientists believe it may be possible to use stem cells to correct the deficit. According to the Parkinson's Disease Foundation, stem cells can be obtained from two different types of sources. One source is the embryonic stem cell, a primary cell that has the potential to develop (differentiate) into almost any type of cell. Embryonic stem cells either are harvested directly from a blastocyst (a group of cells in an embryo) or are derived by a process called somatic cell nuclear transfer (SCNT). Blastocysts are obtained at in vitro fertilization clinics; in SCNT, the nucleus of an adult cell is fused with an unfertilized egg. The other type of stem cell is the adult stem cell, a stem cell that has already developed into a tissue-specific cell. According to the Parkinson's Disease Foundation, isolated human brain cells have the "most immediate potential therapeutic value" for Parkinson's.
Cultivation
According to the University of Minnesota, the hope is that once stem cells are obtained, they can be cultivated (grown in cultures) to become dopamine-producing cells. Cells are isolated and placed into a petri dish. Conditions like temperature and humidity are carefully controlled, and various substances such as growth factors are added to the dish; these growth factors would be responsible for cultivating unspecified stem cells to become dopamine-producing brain cells.
Transplantation
Once the stem cells are cultivated, the goal is to replace to dead dopamine-producing cells with the new cells. If the transplant is successful, the new cells would make enough dopamine to alleviate symptoms. However, this research is still in the experimental phase. As reported by the American Federation for Aging Research, in a transplant experiment with rats that had a disease similar to Parkinson's, cultivated dopamine-producing cells were surgically implanted into different regions of the brain; areas of particular interest were the substantia nigra, hypothalamus and ventral tegmental area, since they are the beginning of the dopamine pathways, according to the University of Utah. When an autopsy was done on the rats 20 weeks after the transplant, the cultivated stem cells had moved and differentiated into other types of brain cells. This research gives hope that transplantation of dopamine-producing cells into humans could one day be successful.
