The objective of the project is to understand the mechanism of action of opiate and opioid peptides at the biochemical and physiological level by making use of neurotumor clonal cell lines which express different types of opiate receptors. The goals for the coming year are to continue studies on the cellular changes which result from acute or chronic exposure to opiates, specifically focussing on adenylate cyclase, protein kinase and glycosyltransferase linkage, and changes in ion fluxes and membrane potential. For these studies we will use cell lines N4TG1 and NG108-15 which express only DELTA (enkephalin) receptors, NCB-20, which express two BENZOMORPHAN (KAPPA AND SIGMA) receptors in addition to DELTA, and TCX-17 (which may express MU (MORPHINE) receptors in addition to DELTA receptors.