Scientists develop needle-thin brain implant with three functions

Scientists have created a needle-thin brain implant that can record neural activity, deliver drugs, and stimulate multiple brain regions simultaneously using a single flexible fiber, with successful tests in mice suggesting potential for treating neurological disorders like epilepsy. The device, called the microfluidic Axialtrode (mAxialtrode), was developed by researchers from DTU, the University of Copenhagen, University College London, and other institutions. It features a light-conducting core surrounded by eight microscopic channels that can transport liquids and hold ultra-thin metal wires for measuring electrical activity. Unlike conventional flat-ended optical fibers that interact with brain tissue only at their tip, this implant provides multiple functional points along its length, allowing researchers to target different brain layers at once. The findings were published in the journal Advanced Science. The implant is made of soft, plastic-like optical fibers with a specially angled tip, reducing tissue damage and inflammation compared to harder silicon-based implants. In living mice, the device successfully stimulated nerve cells with blue and red light while recording electrical activity from shallow and deep brain regions, and injected substances at delivery points nearly three millimeters apart. The technology is primarily intended as a research tool for studying epilepsy, memory, and decision-making, but researchers caution it remains far from routine clinical use, requiring extensive testing and regulatory approvals before patient applications.