Binding Neurons to Implants
A new method of integrating electrodes and neurons into a single device, offers some tempting possibilities for new neuroprosthetics, and nerve-operated prosthetics in general.
Professor Yael Hanein of Tel Aviv University's School of Electrical Engineering has developed a spaghetti like mass of nano-sized ) carbon tubes, and using an electric current has managed to coax living neurons from the brains of rats to grow on this man-made structure. So in other words, the nerves fuse directly with the electronics. If electrodes are placed with the tubes, or the tubes are used to channel current directly, you have a perfect connection.
"We're working to interface man-made technology with neurons," she stated. "It can be helpful in in-vitro and in in-vivo applications, and provides an understanding of how neurons work so we can build better devices and drugs."
The growth of living cells on the nano substrate is a very complicated process, she says, but they adhere well to the structure, fusing with the synthetic electrical and physical interface. Using the new technology developed in Hanein's laboratory, her graduate student Mark Shein has been observing how neurons communicate and work together.
"We are attempting to answer very basic questions in science," Prof. Hanein explains. "Neurons migrate and assemble themselves, and using approaches we've developed, we are now able to 'listen' to the way the neurons fire and communicate with one another using electrical impulses. Listening to neurons 'talking' allows us to answer the most basic questions of how groups of nerves work together. If we can investigate functional neuronal networks in the lab, we can study what can't be seen or heard in the complete brain, where there are too many signals in one place."
The applications are of course, legion. But it is a long way from lab based results to implantation in a live animal, which will be the next step. After that, the two are shooting fairly low, with plans to start working on optical implants, using the technology to mesh neurons directly with the implant technology, for a much stronger signal.
"Neurons like to form good links with our special nanotechnology, and we're now investigating applications for retinal implants," said Hanein. "Our retinal implant attempts to replace activity in places of the damaged cells, and in the case of retinal diseases, the damaged photoreceptors."