Adaptive coding in piriform cortex neurons after odor-spatial context associative learning.

NOEL FEDERMAN; SEBASTIAN A. ROMANO; LUCCA SALOMON; ANTONIA MARIN BURGIN

Congreso; XXXVII Congress of the Argentine Society for Research in Neuroscience (SAN). Buenos Aires; 2022

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. We study how activity in the primary olfactory cortex of mice is modulated by sensory and non-sensory variables related to an odor-spatial context associative task, before and after learning. For this, we recorded piriform cortex (PC) activity in head-fixed mice trained to explore a virtual corridor in which they learn that a specific odor is associated with a reward only when presented in a particular visual context. We found that neurons in the PC respond not only to odors but also to several task-relevant variables. Furthermore, the ability of neurons to encode more than one variable is acquired with learning, since animals in the first session of training have fewer multiplexing neurons. Importantly, by using the activity of the population of PC neurons we can decode trial contextual information during expert animals’ behavior, while only odor information can be decoded from populational activity of first session animals’ neurons, further indicating that associative learning dynamically modifies the representation in the PC to reflect experience. This suggests an adaptive coding in this primary sensory cortex useful to adjust behavior after learning.