Another step forward for the field of regenerative medicine: researchers have "discovered a novel way to convert human skin cells into brain cells ... Rather than using models made in yeast, flies or mice for disease research, all cell-reprogramming technology allows human brain, heart and other cells to be created from the skin cells of patients with a specific disease. The new cells created from the skin cells contain a complete set of the genes that resulted in that disease - representing the potential of a far-superior human model for studying illnesses, drugs and other treatments. In the future, such reprogrammed skin cells could be used to test both drug safety and efficacy for an individual patient with, for example, Alzheimer's disease.
... This technology should allow us to very rapidly model neurodegenerative diseases in a dish by making nerve cells from individual patients in just a matter of days - rather than the months required previously. ... used two genes and a microRNA to convert a skin sample from a 55-year-old woman directly into brain cells. (MicroRNAs are tiny strands of genetic material that regulate almost every process in every cell of the body.) The cells created [exchanged] the electrical impulses necessary for brain cells to communicate ... Using microRNA to reprogram cells is a safer and more efficient way than using the more common gene-modification approach. In ensuing experiments, [the researchers hope] to rely only on microRNAs and pharmaceutical compounds to convert skin cells to brain cells, which should lead to more efficient generation of cells for testing and regenerative purposes."

Link: http://www.sciencedaily.com/releases/2011/07/110728123107.htm