Abstract: Dopamine (DA) is an important biogenic amine in invertebrates and vertebrates. It is involved in the regulation of a variety of physiological responses and behavior of insects, such as learning and memory, cognition, sexual orientation, locomotion, phase change, etc. DA exerts its effects by binding to specific dopamine receptors belonging to the superfamily of G protein-coupled receptors. In this review, we summarized the current knowledge on the modulation of DA, its distribution in nervous and non-nervous tissues, and its physiological functions in insects, such as its involvement in modulating insect mating, development, olfaction and locomotion. Especially, the recent progress about signal transduction, physiological roles and pharmacological properties of insect dopamine receptors was reviewed in detail. There are two families of insect dopamine receptors, D1-like and D2-like. D1-like DARs have two subtypes, DOP1 and DOP2. DOP1 upregulates intracellular cAMP in the presence of dopamine. The second group of invertebrate dopamine receptors, DOP2, not only upregulates cAMP levels but also increases Ca²⁺ levels. The D2-like DARs only have one subtype, DOP3, which downregulates intracellular cAMP in the presence of dopamine. DA-mediated generation of second messengers is associated with changes in cellular response, affecting insect behaviors. Pharmacological characterization of insect dopamine receptors may help us develop new specific insecticides for pest management.

Key words: Dopamine, dopamine receptors, Gproteincoupled receptors, behavior, phase change, pharmacology