G protein-coupled receptors are involved in the regulation of many aspects of normal physiology and pathology. Recent research has broadened our view of how the cell trans-duces ligand binding to cellular responses. It is becoming clear that phenomena that take place both at the cell surface, such as receptor oligomerization, as well as intracellularly, such as interaction between different signaling pathways, have important roles in the response elicited by a ligand. The study of these events requires the combined use of classical biochemical techniques with novel methods that allow analysis of these mecha-nisms. This chapter gives an overview of both types of techniques, with an emphasis on discussing their main applications and the conclusions that can be drawn in each case.
