UC San Diego

The olfactory system is crucial for survival in mice, supporting a variety of behaviors including foraging, social interaction, and predator avoidance. Bypassing the thalamus, the olfactory bulb acts as the first sensory processing center for odors, then sending olfactory information throughout the olfactory cortex and other higher order structures. Within these networks, there also are genetically preserved pathways that support odor-driven innate attractive and aversive behaviors, connecting to structures such as the nucleus accumbens and posterolateral cortical amygdala. Moreover, structures in the olfactory cortex like the piriform cortex displays a level of plasticity that allow olfactory learning, which is further supported by reciprocal connections with higher order structures. This review focuses on providing an understanding of the olfactory system as well as odor-driven innate and learned behaviors, with a final focus on providing an evidence-based hypothesis that the orbitofrontal cortex is involved with an odor-learning based override of innate behavior.