Dnmts mediate neural processing after odor learning in the honeybee

DNA methyltransferases (Dnmts) epigenetic writers catalyzing the transfer of methyl-groups to cytosine regulate stimulus-specific olfactory long-term memory (LTM) formation and extinction in honeybees. The physiological relevance of their function in neural networks, however, remains unknown. Here, we investigated how Dnmts impact neuroplasticity in the bees’ primary olfactory center, the antennal lobe (AL) an equivalent of the olfactory bulb of vertebrates. The AL is crucial for odor discrimination, an indispensable process in stimulus-specific LTM. Using pharmacological inhibition, we show that Dnmts promote fast odor pattern separation in trained bees. We show Dnmt activity during memory formation increases both the number of responding glomeruli and the response magnitude to a novel odor. These data suggest that Dnmts are necessary for a form of homoeostatic network control which might involve inhibitory interneurons in the AL network and demonstrate that Dnmts influence neural network properties during memory formation in vivo.