CONICET | Buscador de Institutos y Recursos Humanos

Sensory representations are typically thought as neuronal activity patterns that encode physical attributes of the outside world. However, both internal state and behavioral relevance of a stimulus may modulate neuronal coding in sensory cortical areas. To study this phenomenon, we developed a behavioral task in a virtual reality environment in which head-fixed mice learn that an odor is rewarded when presented in a specific spatial context, and recorded neuronal activity in piriform cortex (PC). We find neurons not only responding to odors, but also to visual contexts and to water reward, indicating that the PC encodes information about relevant aspects of the task. Moreover, using Principal Components Analysis (PCA) of population activity dynamics, we show that population trajectories evolving thorough time can discriminate aspects of different trial types. Through Generalized Linear Models (GLMs), we further dissect the contribution of different variables to the modulation of PC activity at the level of individual trials. We show that, after learning the task, animal position in the virtual environment has considerable impact on PC responses. Furthermore, we found that variables related to both sensory and behavioral aspects of the task (e.g., odor, context, reward, licking, sniffing rate and running speed) differently modulate PC activity, suggesting that the PC may use information from other brain areas to adapt odorprocessing depending on experience and behavior.