In the last ten years great strides have been made in our knowledge of the nucleus locus coeruleus (LC), its brainstem and spinal cord connections and their effects. For example, in 1978 it was commonly held that the LC consisted of cells which contained norepinephrine (NE) and only NE and that their activity produced inhibition of all the neurons they contacted. Both of these concepts have been shown to be woefully incomplete, since we now know that the postsynaptic effect can be facilitation or inhibition dependi g on the NE receptors involved; the discovery of colocalization of neuropeptides further compounds the postsynaptic possibilities of action. There still remains much that is unknown about the LC, its inputs, outputs and effects. It is the intention of conference organizers to bring togethe an international group of 24 scientists--each of whom is working on the LC and its brainstem or spinal cord effects utilizing a different technique or approach. Seminars, each with approximately four scientists making presentations, will address the following topics: The Physiology of LC cell , Inputs and Transmitters, Anatomy of Coerulospinal Pathways, Brainstem Interactions, and Interneuron and Motoneuron Effects. It is anticipated that through the formal presentations, as well as through informal discussions among the participants during the conference, there wi l emerge a better understanding of the overall functioning of the LC. This, in turn, should stimulate more focused investigations while encouraging a spirit of collaboration among the participants.