To treat severe cases of Parkinson's disease, surgeons implant electrodes deep in the brain, where they deliver high-frequency electrical pulses that shut down neural systems responsible for the disease's characteristic tremors. But this expensive treatment, called deep brain stimulation, is risky: the patient's skull must be opened, and the electrodes can damage blood vessels in the brain.

A new type of polymer nanoelectrode, however, could make brain implants far safer and less costly. Rodolfo Llinas, a professor of neuroscience at New York University, has worked with Ian Hunter, a professor of mechanical and biological engineering at MIT, to develop a nano-wire electrode just 600 nanometers across -- so thin that it could be inserted through an artery in the arm or groin, threaded up to the brain, and snaked through the smallest blood vessels, getting close enough to neurons to detect and deliver electrical signals.