**Table 1.**

*Functional and physiological knowledge of dopamine receptors.*

Several BAs, such as dopamine, serotonin, octopamine and tyramine, are crucial for olfactory learning behavior in honeybees [23]. Among all these BAs, dopamine is the major receptor and performs a vital role in the olfaction success of honeybees. In both vertebrates and invertebrates of the animal kingdom, dopamine receptors are present in the central nervous system and regulate multiple tasks. The dopamine receptors are divided into two families D1-like family and D2-like families. The D1-like family (D1, D5) and D2-like family (D2, D3, D4) actively regulate and modulate cell proliferation, differentiation, the release of cyclic adenosine monophosphate (cAMP) and other neurotransmitters also [24]. In this chapter, we focused on the learning behaviors of honeybees, especially olfactory learning behavior. Our focus is the practical functions of dopamine receptors, including olfactory learning, motivation, social behaviors, reward system, cognition, movement, emotion, etc., for forming appetitive and aversive learning [25]. Dopamine receptors catecholamine neurotransmitters work as catecholamine release, vascular tone, cardiovascular function, gastrointestinal motility, hormone secretion and renal function. The scientific community has been investigating over four decades that several diseases like schizophrenia, hyperprolactinemia, Tourette's syndrome and Parkinson's disease have been associated with dysregulation (erratic breathing, heart rate, thinking and behavior) of transmission of dopamine neurotransmitters [26].

D1-like receptors (D1 and D5) are located in different body parts. Dopamine D1 receptors are usually located at the Olfactory bulb, nucleus accumbens, striatum, amygdala, hippocampus, frontal cortex, substantia nigra, and hypothalamus and perform various functions, including Attention, learning, locomotion, sleep, impulse control, regulation of renal function and memory. **Table 1** shows the details and knowledge of the function, location, mechanism, type, selective agonist and selective antagonist of all dopamine receptors.

Dopamine receptors control olfactory learning behaviors and insect reproduction [27]. These receptors are responsible for various bodily functions, but dopamine receptors' major functions are reward-seeking, learning and other physiological properties. These receptors have distinct patterns and functional properties to compose the learning and memory in the brain. In insects like honeybees, *Drosophila melanogaster* and rodents, dopamine receptors and the basolateral amygdala are critically important for learning behavior. The mushroom bodies (MB) of *Drosophila melanogaster* and honeybees have a rich center for dopamine for olfactory learning and olfaction success and also provide a tractable mechanism to investigate the interaction between olfactory learning and dopamine receptors [28, 29]. This chapter will provide the basic interaction of dopamine receptors and olfactory learning behavior; olfactory learning behavior is important for colony survival. The functions of dopamine provide concrete evidence of how dopamine receptors are crucial and contribute to honeybees' olfactory behavior. Further study is required to investigate the role of dopamine receptors in managing the pest *varroa* mites of honeybees by using grooming behavior.
