Defensiveness measurement in honey bees (Apis mellifera)and brain expression of associated genes after noxious stimulus

Abstract

Honey bee (Apis mellifera sp.) colonies and individuals respond variably to disturbances. In this study, we examined the role of neural modulation and metabolism in constitutive and experience-dependent differences in defensive response. We compared brain gene expression in bees of identified gentle and defensive colonies in a standard assay. For neuromodulation, we examined membrane receptor genes for the biogenic amines dopamine (DOPR2), octopamine (OAR), and serotonin (5HT2a), and the enzyme gene in the synthesis pathway (THR). To examine neural metabolism, we assessed the Oxidative Phosphorylation Pathway "OXPHOS" gene expression (i.e., ND51 and ND20-LIKE). Bees of defensive colonies had a significantly lower expression of amine receptor, synthesis genes, and OXPHOS genes. Experience differences or exposure to nociceptive neurons activated by nocive stimuli (electric shock) led to differences in the expression of all genes except 5HT2a. The same target genes demonstrated an increase in expression levels after electric shock and sting response. We discuss the convergence of neuromodulation, neural metabolism