Galanin receptor subtypes and ligand binding

Galanin is a neuropeptide initiating its multiple biological effects by binding to different subtypes of seven transmembrane spanning galanin receptors, thus transducing the extracellular signal to G-proteins. There is a wide range of galanin receptor ligands available today, and some of the ligands have been shown to act as antagonists in galaninergic signal transduction systems at tissue level and in vivo. Subtype-specific galanin receptor ligands could be used selectively to initiate or block the effects of galanin in order to provide insights into the role of galanin both at normal and pathophysiological conditions, and in the development of compounds with therapeutical values. This review highlights the recent reports on the binding affinities of GalR in CNS and transfected cell lines.