Life Neuroscience

Learning and memory are essential for adaptive behavior and survival, and the honey bee provides a valuable model for investigating the neural mechanisms. The mushroom bodies are important centers for sensory integration, learning, and memory in the insect brain, particularly during olfactory conditioning. This study investigated the involvement of mushroom body-related neural processes in the formation and consolidation of long-term olfactory memory in honey bees. Adult worker bees were subjected to an olfactory conditioning paradigm using the proboscis extension response (PER), in which an odor was paired with a sucrose reward. Long-term memory was evaluated 24 h after conditioning. Brain tissue was subsequently collected for RNA extraction and reverse transcription quantitative PCR analysis. The expression levels of three memory- and plasticity-related genes, AmCREB, AmCaMKII, and AmNmdar1, were compared between conditioned and control groups. Conditioned bees showed a marked increase in PER following training and retained a strong response 24 h later, indicating the formation of long-term olfactory memory. Molecular analysis showed increased expression of AmCREB, AmCaMKII, and AmNmdar1 in conditioned bees compared with controls. These findings indicate that successful olfactory learning and long-term memory are associated with changes in the expression of genes involved in neuronal plasticity and memory-related signaling. Although whole-brain analysis does not allow the molecular changes to be attributed specifically to the mushroom bodies, the behavioral and molecular findings are consistent with the involvement of mushroom body-related neural mechanisms in long-term olfactory memory.