It is indeed a pleasure to welcome all of you to this Inter­ national Symposium on the Neurohumoral coding of Brain Function. Many of you have undertaken a very long trip in order to cross swords with some of the most fascinating issues in all of the neurosciences. Of particular satisfaction in this instance is the geographical representation of the sciences with individuals here from Europe and the Americas - South, Central and North. As we do battle, so to speak, with each of the questions raised during the next several days, we should remember that the problems faced by each of our fields are exceptionally difficult. In a way, this difficulty stems from two related facts: (1) we are trying to construct a conceptual bridgework between one disci­ pline and another; and (2) the distance between the research fabric of any two of these disciplines is vast. It would probably not be unfair to say that a large number of scientists feel relatively contented in remaining within the bound­ aries of their own area of specialization. In a sense, that is certainly justifiable today primarily because of the intensity of such specialization. However, the participants of this symposium, who reflect some of the major thrusts in biochemistry, physiology, pharmacology and psychology, have in the main chosen to explore the pathways that cross the interface between mind and body - be­ tween behavior and brain.