Biogenic amines mediate learning success in appetitive odor conditioning in honeybees

Abstract

Objectives: Biogenic amines modulate the honeybees' behavioral development, especially olfactory learning behavior. Diverse behavioral protocols have been developed to investigate the olfactory learning behavior of bees to process appetitive olfaction information. Apis mellifera ligustica is a well-known eusocial insect to examine the olfactory learning behavior. This study evaluated the relationship between olfactory learning success and biogenic amines and uncovered the role of biogenic amines to regulate the olfactory learning behavior of bees. Methods: We used high-performance liquid chromatography (HPLC) with an electrochemical detection (ECD) system to quantify neurotransmitters levels in the bee brain following olfactory learning trials. Furthermore, the bees of the control group and the dopamine flupenthixol blocker injected group were trained to evaluate the olfactory learning performance. Results: Our finding showed that learning success was directly correlated with the levels of DA and serotonin (5-HT), furthermore, bees of the control group showed higher proboscis extension response than dopamine blocker injected group. Taken together, these findings revealed that dopamine (DA) and serotonin (5-HT) could thus act together to define optimal motivational or attentional levels and improve learning success and indicated that dopamine blocker flupenthixol has to modulate influence on the olfactory learning performance of bees. Conclusion: The results strongly imply that biogenic amines can durably modify the learning behavior in future model insects.

Keywords

• Biogenic amines
• Proboscis extension response
• 1-nonanol
• Odor
• Apis mellifera
• 1-hexanol