Papers are invited for a JAMA/ARCHIVES joint theme issue on Medical Applications of Biotechnology in early 2005. Please submit papers pertinent to neurological applications of biotechnology: neuroimaging; laser capture microdissection; stem cells; microarrays for DNA, RNA, or protein; DNA polymorphisms; genetic engineering; nanotechnology; neuroprosthetics for vision, hearing, and movement; and other important emerging biotechnologies that enhance new therapies. Papers received by August 1, 2004, have the best chance of acceptance.