Low-molecular-weight chemicals, which are produced and secreted by neurons and a limited range of non-neural cells, are the major vehicles for communication of nerve cells with each other and with neurally controlled non-neural cells. Research over the past several decades has identified a wide spectrum of such neuromediators, delineated their structures, elucidated pathways of biosynthesis and biodegradation, and determined the processes of development and function that they influence physiologically. These results have revealed the nature of cellular receptors that recognize neuromediators selectively and the pathways that transduce signals from neuromediator-occupied receptors to the target cells. For most neuromediators and their receptors, pharmacological agonists and antagonists of high specificity also have been discovered or designed and synthesized. In the past decade, a broad range of animal models has been developed in which modern genetic methods have allowed overexpression and deletion of neuromediators and/or of their receptors for sophisticated analyses of their roles in normal physiology and some diseases. The availability of pharmacological agents directed to neuromediators or their receptors also has stimulated early studies of the involvement of these systems in some human diseases. At the same time as these revolutionary advances, most established conference series dedicated to this subject area have become narrower and have focused more sharply on individual neuromediators to permit deeper and more penetrating presentations and discussions. At this time, it seems appropriate to organize a volume that examines the conceptual, methodological, and practical progress in the field from broader biological and pathophysiological perspectives. This volume describes a new international conference in the integrated field of neuromediators that has no predecessors and is set in a biomedical context of possible diagnostic and therapeutic approaches. NOTE: Annals volumes are available for sale as individual books or as a journal. For information on institutional journal subscriptions, please visit www.blackwellpublishing.com/nyas. ACADEMY MEMBERS: Please contact the New York Academy of Sciences directly to place your order (www.nyas.org). Members of the New York Academy of Science receive full-text access to the Annals online and discounts on print volumes. Please visit http://www.nyas.org/MemberCenter/Join.aspx for more information about becoming a member