The function of the central nervous system as a coordinator and regulator of cellular processes in multicellular organisms is unequivocal. Until recently, however, the chemical evidence necessary for validating speculations on neurophysiological function in inverte­ brates has been lacking. In insects, because of their small size, heroic efforts were needed to collect the millions of tissues or organs necessary for isolation and identification of neurochemicals. With the spec­ tacular advances in physical and analytical technology within the last decade and with significant advances in radiochemical, radioimmunological and neurophysiological assays, researchers are, for the first time, able to handle microgram and nanogram quantities of complex biological substances. More recent developments in immunology promise to lower these levels further. It is not surprising that these new opportunities accelerated progress in insect neuroscience and that the time was right for a rapid and personal exchange of ideas and information on techniques. These considerations were the primary impetus for convening the International Conference on Insect Neurochemistry and Neurophysiology (ICINN) at the University of Maryland, College Park, MD, on August 1-3, 1983.