we might seek alternative sources of donor tissues. Genetic en- neering, expansion of precursor cells, generation of immortalized cell lines, and transplantation between species are all under active investigation. Although significant difficulties remain for each of these alternatives, the problems appear soluble and relevant knowledge is expanding rapidly. As we enter the twenty-first century, the place of neural tra- plantation in experimental neuroscience is continuing to evolve. Rather than being a topic in its own right, neural transplantation increasingly serves as just another technique in the researcher's armory--alongside lesions, pharmaceuticals, gene transfer, and a variety of other techniques--for the experimental manipulation of brain structure and function. This is particularly true for studies of degeneration, plasticity, regeneration, and recovery of function in the nervous system, topics of increasing importance as experimental neurobiology is required to serve the higher needs of neurological and mental health in aging societies. Within this evolving context, Neural Transplantation Methods seeks to serve a particular need: to provide experimental neu- scientists with a source book of information to enable them to select and adapt transplantation techniques to their own expe- mental programs. All authors have been asked to address prac- cal issues, to enable the reader to assess what is available, what are the alternatives, what are the practical issues to be resolved in applying a particular protocol and getting it to work reliably in their unique experimental context.