The International Life Sciences Institute (ILSI) was estab lished in 1978 to stimulate and support scientific research and educational programs related to nutrition, toxicology, and food safety, and to encourage cooperation in these programs among scientists in universities, industry, and government agencies to assist in the resolution of health and safety issues. To supplement and enhance these efforts, ILSI has made a major commitment to supporting programs to harmon ize toxicological testing, to advance a more uniform inter pretation of bioassay results worldwide, to promote a common understanding of lesion classifications, and to encourage wide discussion of these topics among scien tists. The Monographs on the Pathology of Laboratory Ani mals are designed to facilitate communication among those involved in the safety testing of foods, drugs, and chemicals. The complete set will cover all organ systems and is intended for use by pathologists, toxicologists, and others concerned with evaluating toxicity and carcinogen icity studies. The international nature of the project - as reflected in the composition of the editorial board and the diversity of the authors and editors - strengthens our ex pectations that understanding and cooperation will be im proved worldwide through the series. Alex Malaspina President International Life Sciences Institute Preface This book, on the nervous system, is the sixth volume of a set pre pared under the sponsorship of the International Life Sciences Insti tute (ILSI)."

The International Life Sciences Institute (ILSI) was creat ed to promote cooperative efforts toward solving critical health and safety questions involving foods, drugs, cosmet ics, chemicals, and other aspects of the environment. The Officers and Trustees believe that questions regarding health and safety are best resolved when government and industry rely on scientific investigations, analyses, and reviews by independent experts. Further, the scientific aspects of an issue should be examined and discussed on an international basis, separate from the political concerns of individual companies. ILSI is pleased to sponsor this set of monographs on the pathology of laboratory animals. This project will be use ful in improving the scientific basis for the application of pathologic techniques to health and safety evaluation of substances in our environment. The world wide distribu tion of the authors, editors, and Editorial Board who are creating these monographs strengthens the expectation that international communication and cooperation will al so be strengthened."

The International Life Sciences Institute (ILSI) was estab lished to stimulate and support scientific research and edu cational programs in nutrition, toxicology, and food safe ty; and to encourage cooperation in these programs among scientists from universities, industry, and government in order to facilitate the resolution of health and safety issues. The officers and trustees of ILSI believe that questions re garding health and safety are best resolved when govern ment and industry rely on scientific investigations, analy ses, and reviews by independent experts. This process is furthered by the examination and discussion of issues on an international basis. ILSI is pleased to sponsor this set of monographs on the pathology of laboratory animals. This project collectively brings together the most comprehensive information on non-neoplastic and neoplastic lesions that occur in com monly used laboratory animals. The international compo sition of the authors, editors, and editorial board who have contributed to these monographs strengthens our expecta tions that understanding and cooperation will be strength ened worldwide through this series."