Abstract: Trace amines are the class of endogenous biogenic amines that traditionally include beta-phenylethylamine, p-tyramine, tryptamine, octopamine, and others. Many trace amines represent products of amino acids decarboxylation by bacterial decarboxylases during tissue putrefaction or by endogenous decarboxylases in the body. Production of trace amines by gut microbiota is also known (Berry et al., 2017; Gainetdinov et al., 2018). Thus, trace amines are enriched during the decomposition of proteins and concentrated in certain bodily fluids. Their physiological action in mammals has been noted a long time ago, however, they were considered mostly as by-products of amino acid and monoamine metabolism. This was changed with the discovery in 2001 of trace amine-associated receptors (TAARs), a family of G protein-coupled receptors that are activated by trace amines. In humans, 6 types of functional TAAR receptors were identified - TAAR1, TAAR2, TAAR5, TAAR6, TAAR8 and TAAR9 (Berry et al., 2017; Gainetdinov et al., 2018). Since then, there is a growing interest in this family of receptors as possible new targets for pharmacotherapy. Indeed, several psychotropic substances have been shown to display high affinity to the most studied of the TAAR receptors - TAAR1, which has notable expression in the brain and some peripheral tissues (Berry et al., 2017). TAAR1 can modulate classical brain neurotransmitter systems - dopamine, serotonin, and glutamate, that are involved in the pathogenesis of many neuropsychiatric disorders. Indeed, the preclinical study of TAAR1 agonists showed them to be promising for the treatment of schizophrenia, drug dependence, depression and bipolar disorder (Berry et al., 2017; Gainetdinov et al., 2018). TAAR1 is already proven clinically as a novel pharmacological target. In clinical trials, TAAR1 agonist showed great promise for the treatment of schizophrenia with a unique mechanism of action not involving D2 dopamine receptor blockade (Koblan et al., 2020). At the same time, all other TAARs have been considered as exclusively olfactory receptors sensing innate odors encoded by volatile amines with no significant function in the brain or the periphery. However, we recently demonstrated that an “olfactory” TAAR5 receptor is present in the limbic brain areas and can regulate classical monoamine systems, emotional behavior, and adult neurogenesis (Espinoza et al., 2020; Efimova et al., 2021).