Odors are represented as ensembles of cortical neurons in mouse olfactory, or piriform cortex. These cells receive diffuse and overlapping afferent sensory inputs from the olfactory bulb. They also form a rich, interconnected recurrent network, where a given cortical pyramidal cell receives inputs from hundreds of other pyramidal cells distributed across piriform cortex. Together, the sensory and recurrent inputs generate odor-specific cortical ensembles. We ask: how are these ensembles formed; how does the cortex discriminate between similar odorants to generate wholly different cortical ensembles; how do cortical ensembles represent odorants at different concentrations; and how are novel versus learned odorants represented?
In combination with various optogenetic and molecular tools to perturb defined elements of the cortical circuit, we use in vivo and in vitro electrophysiology and optical imaging of neural activity, together with behavioral and computational analyses, to understand the generation of odor-specific cortical odor ensembles, and the roles of different cell types within the circuit in shaping these.