S50 Perspective on G Protein-coupled Receptors from Their Structure, Function, Complex Formation, Modeling and Ligand Development S50-1 X-ray crystallographic analysis of the early photo-intermediate of squid rhodoopsin S50-2 3D-structure prediction of GPCRs with ligands using molecular modeling techniques S50-3 Design of GPCR ligands based on the three-dimensional diversity-oriented strategy: development of histamine H3 and/or H4 receptor ligands S50-4 Beta adrenergic regulation of cardiac repolarization via a macromolecular complex of the cardiac IKs channel S50-5 New pharmacological action of beta-blockers