Stem Cells
Stem cells are undifferentiated cells. Stem cells can differentiate into the myriad of cells in the human body, including brain, spinal cord, nerve, blood, muscle or skin cells. Human stem cells were first used during in vitro fertilization, but research on mouse stem cells had been going on prior to the use of human stem cells.

Stem cells can be useful in many types of medical research. Regeneration of damaged spinal cords, or other nerves, is one area of research. Some work has been done with mice, and a group of scientists were able to re-grow part of a severed spinal cord.

Another area of research is in brain tissue, and many diseases such as Parkinson’s disease. In Parkinson’s disease, the brain cells that contain dopamine (an important chemical signal in the brain) receptors degenerate. Researchers have been able to make mouse embryonic stem cells differentiate into dopamine receptor cells by adding a gene called Nurr1. This is the first step towards helping Parkinson’s sufferers.

There are two types of human stem cells: embryonic (from fetuses) and adult (from mature tissues in the human body). Embryonic stem cells can differentiate into any type of cell, whereas adult stem cells can often only differentiate into the tissue they were taken from, though this is not always true. Embryonic stem cells are also easier to culture than adult stem cells. However, adult stem cells could be extracted from a patient and used to treat the same patient for a disease like Parkinson’s. In this way, there is no concern about the immune system attacking the stem cells since it is the patient’s own cells. This technology is still in the development stage, but soon it may be a real possibility.

In 2002, Australia banned the use of human embryonic stem cells that were created in a laboratory for research use. Left over embryonic stem cells from fertility clinics may be used for research purposes.

In 2005, Australian scientists at Griffith University in Brisbane discovered a method of retrieving stem cells from the human nose. This method provides scientists with a source of adult stem cells. Scientists hope that these nasal stem cells will be able to differentiate as well as embryonic stem cells.