For decades, researchers have imagined treating human diseases by replacing damaged cells with stem cells -- embryonic cells from which all other kinds of cells develop. While the potential benefits are enormous, such strategies have been limited by an uncertain supply of stem cells. Now, scientists have shown that neural stem cells can be multiplied and raised to maturity in the laboratory and that these cells can greatly reduce symptoms in an animal model of Parkinson's disease.
The study is the first to show that neural stem cells grown outside the body can form specific kinds of neurons -- in this case, dopamine-producing cells -- and that these neurons can survive and function normally when they are transplanted into the living brain. Dopamine is an important nerve signaling chemical, or neurotransmitter, and the loss of dopamine-producing cells in one region of the brain is responsible for the symptoms seen in Parkinson's disease. The new finding suggests that cells multiplied in culture may ultimately prove useful in treating Parkinson's and other nervous system diseases. It also provides new opportunities for studying how the brain develops that may greatly improve understanding of nervous system disorders, says Ronald McKay, Ph.D., of the National Institute of Neurological Disorders and Stroke (NINDS), senior author of the report which will appear in the August 1998 issue of Nature Neuroscience (1).
"Cells are the ultimate device for delivering substances to the brain, so this could become one of the most widely used therapies in medical research," says Dr. McKay.
Unlike the original cells of the embryo, which can form literally any
kind of cell, neural stem cells are restricted to becoming nervous system cells.
However, they still can develop into all the types of cells that make up the
brain and spinal cord. The process in which cells that start out with unlimited
potential fates develop into specific types
Contact: Natalie Larsen
NIH/National Institute of Neurological Disorders and Stroke