Chemical carcinogenesis in the nervous system: past and future.

The model of experimental tumors of the nervous system has greatly contributed to our understanding of growth and management of intracranial tumors, but has been somewhat neglected in the last years, because a wealth of new data concerning oncogenic action came from viral oncogenesis. These new issues led to a much better insight into human tumor induction and promotion. Yet one example of the impact of oncogenic transformation stems from the "neurooncogenic" model: the discovery of the neu oncogene and its product as a putative differentiation receptor in the cell membrane of experimental Schwann cell derived tumors. In the light of this unique finding the history of the "neurooncogenic" model and the morphological and "clinical" result of tumors produced within the model are reviewed. There is a large open field for future investigation both in basic and applied science.