Microelectrodes are used to record and stimulate neuronal activity in experimental animals and in human therapeutic applications. However, the injury to tissue when they are implanted, and their mechanical mismatch with brain tissue after implantation, can trigger the brain's immune response, causing them to be encapsulated by glia and other cells and preventing current flow between neurons and the electrical contacts. Payne and her colleagues will use the latest in nanotechnology to develop ultra-thin, flexible nanowires made from a biocompatible polymer which, because of their small size and flexibility, may avoid the immune responses triggered by larger electrodes. The nanowires will be inserted into the brain with micro-capillary tubes and will connect individual neurons to external recording and/or stimulating devices. The nanowires can also be coated with specific molecules that will promote attachment to specific neuron types, allowing for precisely targeted recording or stimulation experiments.