G-protein coupled receptors (GPCRs) are targets for 1/3 of the drugs available on the market making research on this class of proteins a very hot topic in the field of drug discovery. γ-amino butyric acid (GABA) and glutamate are respectively the main inhibitory and the main excitatory neurotransmitters in the mammalian central nervous system (CNS). The GABAB receptor (GABAB-R) and the metabotropic ...