Starting in the 1980s scientists began tinkering with the use of gene therapy to treat disease. In 1988, researchers first showed that gene therapy had the potential to benefit the brain. They modified cells to produce a protective protein. In turn, the cells saved neurons that were prone to degeneration in rodent models. Since that time, researchers have been improving the viral vehicles that deliver the genes.
New modifications allow gene therapy to last longer and cause less side effects.
Scientists are testing the refined methods on injuries to the nervous system such as spinal cord injuries and stroke. In addition, they are testing the techniques in animal models of neurodegenerative diseases ranging from Lou Gehrig's disease to Parkinson's disease. Preliminary trials in humans now are underway to test forms of gene therapy that attempt to treat brain cancer. The techniques use a variety of viruses for gene distribution. When altered, it can infect cancer cells with minimal toxicity to normal cells.