Abstract: Dopamine (DA) is an important neurotransmitter, and exerts its effects via specifically binding to dopamine receptors (DARs). Insect DARs can be divided into D1-like DARs, D2-like DARs, and dopamine/ecdysteroid receptor (DopEcR). D1-like DARs have two subtypes, DOP1 and DOP2, both increasing intracellular cAMP via coupling to Gs signaling, and DOP2 can also activate Gq to mobilize intracellular Ca²⁺ signaling. D2-like DARs have only one subtype, DOP3, decreasing intracellular cAMP via coupling to Gi signaling. DopEcR can respond to both DA and ecdysteroids. In this review, we summarized the research progress of the regulation of DA, dopaminergic neurons, and pharmacological properties and physiological functions of DARs in insects in recent years. The genes in the processes of biosynthesis, transport and degradation of DA regulate multiple phenotypes, such as cuticle melanization, wing color and morphology of wing scales. DA is synthesized and released in dopaminergic neurons, and different types of dopaminergic neurons have different functions. With the development of single-cell sequencing and DA real-time imaging technologies in recent years, this will be beneficial to further investigate the functions of specific neurons. The activities of agonists and antagonists of DARs among insects are very different. These pharmacological differences will provide important basis for developing highly effective and selective insecticides targeting insect DARs. DARs are involved in regulating various physiological and behavioral processes in insects, such as feeding, learning, memory, forgetting, courtship, mating, sleep and wakefulness. The continuously successful application of CRISPR/Cas9 in various insects, as well as the combination of abundant genetic manipulation techniques in Drosophila melanogaster, will facilitate us to accurately investigate the functions of DARs.

Key words: Dopamine, dopamine receptor, neuron, signaling transduction, pharmacology; physiological function