The ability to search for food and to acquire environmental knowledge is vital for animal survival. Most of this knowledge comes from olfactory sensing via multiple olfactory systems. For example, a mouse that has eaten a novel source of food is able to socially transfer its expertise to littermates, a behaviour known as “Social Transmission of Food Preference” (STFP). This behaviour implies the activation of the neurons of the Main Olfactory Epithelium (MOE). On the other hand, the essential environmental detection of predator scents to avoid predation in the wild takes place via the activation of the Grueneberg Ganglion (GG) neurons.
We demonstrated thanks to immunostainings that the MOE and the GG neuronal projections into the olfactory bulb (OB) interact via periglomerular cells suggesting a potential signalling collaboration. To assess this notion, we investigated the STFP under different environmental conditions in vivo in mice. We showed that the STFP process is impacted by the presence of danger cues increasing the acquisition of food preference and highlighting the interaction between the GG and the MOE signals. Interestingly, in the process of these STFP experiments, we identified a subpopulation of mice unable to perform STFP correctly and to acquire a food preference. They displayed an increased number of oral-nasal investigations, which moreover lasted a significantly longer time. In the light of these results, we decided to assess the phosphoserine 6 expression in the MOE of these mice with immunostainings and western blots. Interestingly, we observed that they showed an alteration of MOE neuronal activation. We are further investigating these mice at the odorant detection level with calcium imaging experiments and at the signal integration level looking at OB glomeruli activation. Our findings might lead to the identification of a new gene or of a gene population playing a role in odorant detection and thus in the food decision-making.