Context-Dependent Odor Learning Requires the Anterior Olfactory Nucleus

• Published in: Behavioral neuroscience 2020-08, Vol.134 (4), p.332-343
• Main Authors: Levinson, Max, Kolenda, Jacob P., Alexandrou, Gabriella J., Escanilla, Olga, Cleland, Thomas A., Smith, David M., Linster, Christiane
• Format: Article
• Language: English
• Subjects: Animal; Animal behavior; Animal Learning; Animals; Brain - physiology; Brain Lesions (Experimental); Cerebral Cortex - physiology; Contextual Associations; Cues; Discrimination Learning; Hippocampus; Hippocampus - physiology; Information processing; Learning - physiology; Lesions; Male; Odorants; Olfaction; Olfactory bulb; Olfactory Bulb - physiology; Olfactory Cortex - metabolism; Olfactory Cortex - physiology; Olfactory discrimination learning; Olfactory Pathways - physiology; Olfactory Perception; Olfactory Perception - physiology; Olfactory Stimulation; Olfactory stimuli; Rats; Rats, Long-Evans; Sensory integration; Smell; Smell - physiology
• ISSN: 0735-7044; 1939-0084; 1939-0084
• DOI: 10.1037/bne0000371

Learning to associate the context in which a stimulus occurs is an important aspect of animal learning. We propose that the association of an olfactory stimulus with its multisensory context is mediated by projections from ventral hippocampus (vHC) networks to the anterior olfactory nucleus (AON). Using a contextually cued olfactory discrimination task, rats were trained to associate 2 olfactory stimuli with different responses depending on visuospatial context. Temporary lesions of the AON or vHC impaired performance on this task. In contrast, such lesions did not impair performance on a noncontextual olfactory discrimination task. Moreover, vHC lesions also impaired performance on an analogous contextually cued texture discrimination task, whereas AON lesions affected only olfactory contextual associations. We describe a distinct role for the AON in olfactory processing and conclude that early olfactory networks such as the olfactory bulb and AON function as multimodal integration networks rather than processing olfactory signals exclusively.