Target-specific control of piriform cortical output via recruitment of distinct inhibitory circuits

Neural circuits in anterior piriform cortex (APC) are regulated by ongoing sensory activity, but the underlying circuit mechanisms remain elusive. Here we examined the hypothesis that recurrent inhibition differentially regulates layer 2 (L2) principal neuron types, semilunar (SL) and superficial pyramidal (SP) cells. Patterned optogenetic stimulation revealed that recurrent inhibition was stronger in L1 for SL cells but stronger in L3 for SP cells. This target-specific, differential inhibition across layers was largely attributed to the parvalbumin (PV), but not somatostatin (SST), interneuron. Intriguingly, activity deprivation via naris occlusion (NO) revealed that experience specifically regulated the PV, but not SST, circuit, but the overall target specificity was preserved. Together, these results indicate target-specific inhibitory wiring and heightened inhibitory plasticity of PV cells, implicating these mechanisms in odor processing.