Decoupling Motion from Sensory Data: An Emergent Property of a Neural Population in the Piriform Cortex

Modulation of breathing rate is crucial to flexibly explore the olfactory environment. Inhalation gates the perception of scents, and the act of sniffing is necessary for the olfactory percept. In olfaction, sniffing increases the airflow velocity inside the nostrils and the number of odor molecules that contact the olfactory epithelium during each inhalation. Yet, animals can discriminate odor concentration regardless of the velocity of their inhalation. Sniffing and regular breathing differently influence the activity of the olfactory cortex during a single inhalation. Still, the population representation of odor concentration is invariant to fluctuations in the breathing rate. This can be explained by the fact that inhalation speed and odor concentration responses are uncorrelated within and across neurons in the piriform cortex. Thanks to this feature, a faster odor inhalation and an increase in concentration change the cortical activity pattern in distinct ways. This encoding strategy may represent a broader principle by which the brain maintains perceptual stability against the sensory perturbations introduced by active sampling behaviors.