Molecular Insights into Honey Bee Brain Plasticity

The honey bee worker experiences changing sensory environments throughout her adult life as she progresses from a young nurse bee living inside the hive to a forager bee that navigates the outdoors. Honey bees continually process and learn new sensory information, and their brain changes accordingly. Numerous studies have demonstrated age- and experience-dependent variations in neuropil volume and synaptic density of the honey bee antennal lobes (ALs) and the mushroom bodies (MBs), in particular linked to foraging and odor learning. Changes in antennal sensitivity and AL neural activity after olfactory learning have also been documented. Here, we present evidence for molecular changes occurring in the adult honey bee brain. We discuss how sensory experience and learning affect expression patterns of olfactory receptor genes in the antennae and synaptic adhesion molecules in higher brain centres. Our studies indicate the molecular basis of sensory processing is highly plastic throughout life, and that it is regulated by sensory input. We discuss how sensory regulated expression of olfactory receptors and synaptic molecules may provide a basis for understanding anatomical and physiological plasticity of the honey bee brain.