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Nanoparticles let scientists tickle brain cells wirelessly Last Updated: Wednesday, February 25, 2009 | 6:45 PM ET CBC News Using electrical signals to stimulate brain and nerve cells can help people recover from injury and improve the lives of those with Parkinson's disease, but often requires the surgical implantation of electrodes in the brain, which are attached to cumbersome wires. A group of scientists in Cleveland, Ohio, has now found a new method that could one day allow doctors to activate neurons - brain or nerve cells - wirelessly using microscopic beads and light. So far, Case Western Reserve University neuroscientist Ben Strowbridge, chemist Clemens Burda, and members of their research groups have tried their technique on slices of rat brain tissue and published the results in a recent issue of the journal Angewandte Chemie. The method involves placing beads about 10 nanometres wide - far smaller than human cells - close to a neuron. A human hair is about 80,000 nanometres wide. The beads are made of semiconductors that get electrically excited when light shines on them. "Essentially, these are the same particles used to sensitize solar cells," Burda said. The illuminated particles produce an electric field or current that activates the neurons, which respond with their own measurable electrical signals. In Strowbridge and Burda's experiments, the nanoparticles were attached to a very small glass micropipette to make it easier to position the particles, but ultimately the researchers hope to be able to place a layer of particles on the brain. The technique has a number of advantages over current methods to electrically stimulate the brain, Strowbridge said. Current methods involve surgery, a much larger metal electrode, typically one with a contact about one millimetre - one million nanometres - in diameter. It is hooked up to wires that come out of the brain or skin and are attached to a control unit. "It's very invasive and the wires themselves are difficult to deal with," Strowbridge said. In addition, current methods involve stimulation at only one or two sites at a time. With a layer of nanoparticles, the light, and therefore the activation, could be directed to different areas. "There's really no other technology that can do that with this degree of control or spatial resolution." If the nanoparticles were placed near the surface of the skin, it is possible that they could be activated by shining a light through the skin. Otherwise, a fibre optic cable could be used to deliver the light. Strowbridge and Burda chose to use very small particles in an effort to make them as uninvasive as possible. Ultimately, they plan to coat them with a biocompatible glass to ensure they are non-toxic. The technique still needs to be refined and tested on actual rat brains and nerves before it can be applied to humans. Related Internal Links Deep brain stimulation could help memory loss: study Magnetic stimulator aims to treat depression patients Nerve stimulation may help treat cluster headaches Electrical stimulation promising option for Parkinson's Rayilyn Brown Director AZNPF Arizona Chapter National Parkinson Foundation [log in to unmask] ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn