Sensory processing in the brain unfolds through a hierarchy of regions that increasingly abstract and interpret incoming stimuli. While primary sensory cortices have long been considered dedicated to encoding the physical features of stimuli, recent studies in awake, behaving animals challenge this classical view. Neural responses in these areas are now known to be far more dynamic and context-dependent than previously thought.
In this talk, I will present recent findings from our lab that explore how experience shapes odor representations in the primary olfactory piriform cortex (PCx) of mice. Olfactory perception is inherently modulated by context, memory, and internal state, yet how and where these non-olfactory influences are integrated into cortical processing remains unclear. Using electrophysiological recordings in mice performing an odor-guided task within a virtualreality environment, we investigated how visual context and learning influence PCx activity.
Mice were trained to associate specific odors with spatial and visual cues in order to receive a reward. We found that, with learning, PCx neurons shifted from purely sensory responses to mixed selectivity, encoding not only odors but also positional, contextual, and associative information. These extra-sensory modulations were dynamic and task-dependent, enhancing odor decoding specifically during task engagement and in rewarded contexts.
Our results demonstrate that the PCx integrates non-olfactory information early in the sensory hierarchy, and that this integration supports more flexible and behaviorally relevant odor representations. This work reveals a critical mechanism by which sensory cortices can dynamically incorporate experiential and contextual signals to guide perception and action.
Acknowledgements
Argentine Agency for the Promotion of Science and Technology, PICT2020-00360, Swiss
National Science Foundation (SNSF) SPIRIT 216044 and FOCEM-Mercosur COF 03/11
