Neuroimmunology is a rapidly emerging and expanding field of research, propelled by recent findings that have provided evidence that a number of molecules affect the growth and differentiation of cells in both the immune system and the nervous system. It is now recognized that molecules once thought to have actions restricted to the immune system directly affect the proliferation, growth, and differentiation of nerve cells. Similarly, molecules originally identified because they function in the development of the nervous system reciprocate by having effects in the immune system. A major goal of this conference, held under the auspices of the Federation of American Societies for Experimental Biology, is to bring together scientists from diverse fields (such as immunology, neuroscience, pharmacology, and psychology) to explore new ideas, exchange information, and foster collaboration in the study of the interactions between the nervous system and the immune system.