Speaker
Description
The honey bee Apis mellifera is a traditional model for the study of olfactory perception, information processing, and learning abilities. Surprisingly, this species’ sense of taste remains largely understudied compared to the other sensory modalities. Nonetheless, honey bees’ gustatory abilities are crucial for the survival of the species, since they influence food choices and enable the avoidance of toxic substances. My project seeks to fill the gaps in the study of honey bee gustation by exploring the mechanisms underlying taste information processing through two complementary approaches: behaviour and neuroanatomy. First, through the adaptation of the Multi-Capillary Feeder assay (MultiCaFe) on the honey bee, we evaluated the bees’ ability to detect sixteen tastants belonging to three gustatory qualities (salts, bitters, and amino acids), each tested at six different concentrations. This allowed the inference of A. mellifera’s gustatory preferences and the classification of the stimuli as phagostimulants or repellents for this species. Second, we developed a new set-up to perform appetitive associative conditioning experiments, in which bees associate gustatory stimuli with a sucrose reward. This allowed us to demonstrate that bees are able to discriminate between stimuli of the same hedonic value, despite having a limited number of taste receptors (11 GRs). Finally, we performed a neuroanatomical study to describe the gustatory pathways in the honey bee brain by means of fluorescent tracer injections, both in the taste appendages (proboscis, antennae, and tarsi) and in the central brain. We showed that the spatial organization of gustatory appendages is centrally reflected in the distribution of gustatory afferents. The overlap of projections is notable among inputs from the same appendage origin (e.g., between mouthparts) and remains limited between those from different origins (e.g., antennae and mouthparts).
