Functional role of the anterior olfactory nucleus in sensory information processing

Abstract Olfaction, despite being evolutionarily one of the oldest senses, is complex in structure and function. It can distinguish between trillions of odorants, provides orientation, mediates social interactions, and serves as a warning system. Sensory signals from the periphery are first processed in the olfactory bulb (OB) and then distributed to several olfactory cortical structures. Unlike other sensory modalities, this primary sensory information is not relayed via the thalamus. One prominent olfactory cortical region is the anterior olfactory nucleus (AON), a two-layered structure located within the olfactory peduncle. The AON exerts strong reciprocal connections not only to the OB but also to higher brain areas, e.g., the piriform cortex (PCx), thereby serving as a hub for bottom-up and top-down information processing. However, the functional role of the AON is not well-understood. Here, we provide an overview of recent publications investigating the function of AON in olfactory processing and behavior and present a framework for future research on this fascinating archicortical structure.