Our understanding of the functioning of the brain has grown rapidly over the last decade or two. So has our recognition of the possible role of brain dysfunction in diseases considered earlier to be of peripheral or somatic origin. This culminates naturally in a focus on the nature of the influence of the brain on other systems such as the autonomic, neuroendocrine and immune systems. And we must come full circle and question the nature of the influence of these systems on the function of the brain. Thus, we gain a picture of a complex regulatory interaction, fine tuned in normal circumstances to provide each system with necessary information about the status of the other systems and the basis to respond appropriately to changes in each other. This volume provides the proceedings of the first of a series of international symposia intended to review the state-of-the-art understanding and frontier exploration of the above described interregulatory phenomena, with some emphasis on the relevance of this information to the etiology and treatment of disease. The purpose of this first symposium was to lay the groundwork for this continuing endeavor. To accomplish such a goal required bringing together diverse multidisciplinary professionals - eg neurobiologists, immunol­ ogists, psychiatrists, cardiologists and students amongst others.