NEUROECTODERMAL GRAFTING - A NEW TOOL FOR THE STUDY OF NEURODEGENERATIVE DISEASES

Transgenic and knockout mice have contributed much to our current unde rstanding of the role played by single genes during development and in pathological processes of the CNS, such as neurodegeneration. However , embryonic lethality resulting from the disruption of important genes has often hindered the interpretation of such experiments. Grafting o f immature cells from genetically modified organisms into healthy reci pients promises to efficiently bypass this problem. We have used neura l transplantation techniques which allow us to keep CNS tissue of knoc kout and transgenic mice viable for a prolonged period of time in the brain or in the kidney capsule of healthy recipients. We have characte rized biological parameters such as growth, proliferation and differen tiation and also the formation of an intact blood-brain barrier (BBB) after grafting of wild-type telencephalic anlage in this system. We ha ve also employed this technique to study the longterm properties of ne uroepithelial tissue derived from knockout mice. The results of our st udies are discussed in the context of neurodegenerative diseases.