27 Oct 2000

Following on the heels of a report on a two-gene therapy approach to rescue neurons in a mouse Parkinson's model, a new study published today in Science finds that GDNF genes delivered by a lentiviral vector reversed functional deficits and prevented neurodegeneration in a primate model. The lenti-GDNF was injected directly into the striatum and substantia nigra, where it induced a high level of GDNF expression. What's more, the introduced genes continued to express GDNF for as long as eight months. Before introducing the gene therapy into humans, there are several technical hurdles to surmount, notes Lars Olsen in an accompanying Perspective. Methods to control the dose and expression level of the GDNF will be important, Olsen notes, because excessive dopamine can result in ill effects, including psychosis. It will also be important, he says, to detect Parkinson's disease early enough while enough neurons remain to be rescued.—Hakon Heimer