Abstract: Octopamine (OA) and tyramine (TA) play various important physiological roles in insects. They modulate various organs and behaviors in a coordinated way, such as peripheral organs, learning and memory, circadian rhythm, etc. OA and TA are considered to be the invertebrate counterparts of adrenaline and noradrenaline in vertebrates. They are decarboxylation products of the amino acid tyrosine. Although tyramine is the biological precursor of octopamine, both compounds are independent neurotransmitters, acting through distinct G protein-coupled receptors. In recent years, OA and TA in insects, especially their receptors, have attracted more studying. In this review, we summarized the current knowledge on the biosynthesises of OA and TA, distributions in nervous and nonnervous tissues, presynaptic reuptakes and various physiological functions in insects. Especially, the recent progress about gene cloning, signal transduction and pharmacological characterization of insect octopamine and tyramine receptors was reviewed in detail.

Key words: Biogenic amine, octopamine, tyramine, G protein-coupled receptor, pharmacology, insecticides