Understanding neurotransmitter receptors: Molecular biology-based strategies

• Neurotransmitter receptor proteins can be divided into GPCRs and ligand-gated ion channels. Members within each family utilize a similar signalling mechanism and are structurally related. • Multiple receptor subtypes are expressed for individual neurotransmitters, generating orders of complexity that have been exploited for therapeutic intervention. • GPCRs have been cloned and extensively studied by using a range of molecular biological strategies, particularly recombinant expression systems. These have located functional domains for ligand binding and G-protein coupling. • A combination of molecular biology and computer modelling has increased our understanding of receptor activation and will aid drug design.