Session: 2

PS2-13 | Learning induces signatures of context-dependent processing in olfactory cortex

Noel Federman


Primary sensory cortices are considered as brain regions functionally specialized to encode physico-chemical attributes of the sensory environment. However, the animal’s internal state as well as its ongoing motor behavior can affect cortical activity. In the present work, we study how activity in the primary olfactory cortex of mice is modulated by sensory and non-sensory variables related to a context-dependent olfactory decision-making task. For this, we recorded piriform cortex (PC) activity in head-fixed mice trained in a GO/NO-GO task where they explore a virtual corridor to learn that a specific odor is associated with a reward only when presented in a particular visual context. We found that, throughout task learning mice develop adaptive anticipatory behaviors and change their decision-making behavioral strategies, first learning to discriminate odors, then reducing their bias for GO responses, and finally associating odors to visual contexts.
Using statistical models of neuronal activity, we reveal that after learning, but not before, visual context can be successfully decoded from PC spiking activity. Furthermore, task variables such as odor, inhalation rate, virtual spatial position, locomotion speed, licking and reward strongly shape neuronal activity, inducing a reorganization of PC representations after learning. This suggests that the PC may use information from other brain areas to adapt odor processing depending on experience and behavior.