Primary olfactory cortex encodes context and reward information in the olfactory representation

NOEL FEDERMAN; ANTONIA MARIN-BURGIN; MACARENA AMIGO DURÁN; SEBASTIÁN ROMANO

Ciudad Autónoma de Buenos Aires

Congreso; Scientific Advisory Board en el IBioBA-CONICET-MPSP; 2019

Instituto de Investigación de Biomedicina de Buenos Aires ? CONICET ? Instituto Partner de la Sociedad Max Planck

Sensory representations have been largely thought as fixed brain configurations of the outside world. However, increasing evidence is showing that as animals learn the association between a sensory stimulus and its behavioral relevance, stimulus representation in sensory cortical areas can change. Moreover, internal state as well as animal movements related to a particular task have been shown to modulate cortical activity. To study how is the dynamics of sensory cortex representations as the behavior evolves, we developed a spatial context-olfactory task in which mice learn that an odor is rewarded when presented in a specific spatial context. We measured the activity of piriform cortex (PC) neurons in head fixed mice running in a virtual reality environment. We find neurons not only responding to odors, but also to visual contexts and to water reward, indicating that the PC encodes information about all aspects of the task. Moreover, by analyzing the activity of the population of recorded neurons using Principal Components Analysis (PCA), we find different trajectories evolving through time that can separate aspects of different trial types. We then further dissected the contribution of different sensory and non-sensory variables on the modulation of the PC activity at the level of individual trial spike trains using a statistical approach based on generalized linear models. Our preliminary results show that after animals have learned the context-odor-reward association, linear track position is a spatial element of the task that has considerable weight on the PC responses. Furthermore, we found that variables related to both sensory and non-sensory aspects of the task (as odor, context, reward, licking, sniff rate and running speed) differently modulate PC activity, suggesting that the PC may use information from other brain areas to adapt odor processing depending on experience and behavior.