Odor-evoked food neophobia and attenuation in mice

Animals, including humans, exhibit caution when encountering novel foods, a phenomenon known as food neophobia. This hesitancy decreases with repeated exposures, provided the food is perceived as safe. While extensive research has established rodent models of food neophobia using fluid consumption tasks, studies using solid foods, particularly in mice, are relatively limited. We investigated food neophobia in mice using an olfactory-based task in which the mice were given chow odorized with isoamyl acetate. We quantified several behaviors associated with novelty response and found that the time to begin eating is the most reliable measure of neophobia. Similar levels of neophobia were found using other monomolecular odorants, suggesting that the effect is not odor specific. Further, as some reports of food neophobia in humans have suggested sex differences, we compared food neophobia behaviors in male and female mice. We observed no significant differences between the 2 groups, suggesting that the behavioral expression of food neophobia is similar across sexes. Finally, we found that food neophobia is attenuated upon a second exposure, as mice consume the odorized food as quickly as nonodorized food. Overall, our findings highlight a simple, single-test session approach for exploring olfactory-driven food neophobia.