Non-linear dendritic integration in frontal circuits shapes sensory discrimination in rodents

Abstract

Survival critically depends on the ability of animals to select the appropriate behavior in response to threat and safety signals from the external world. However, the synaptic and circuit mechanisms by which the brain learns to encode accurate predictors from noise remain largely ignored. Here, we show that frontal association cortex (FrA) dendrites discriminate auditory modalities through the recruitment of non-linear, NMDARs-dependent conductances. These active dendrites can further modify membrane potential dynamics by specifically integrating auditory cues and basolateral amygdala (BLA) inputs. This cooperative mechanism critically shapes the expression of safety vs. fear memories generated from sensory cues that were not explicitly paired to an aversive event (e.g., a footshock) during fear conditioning. Taken together, our data reveal a dendritic mechanism for cue discrimination in FrA, thus providing a new framework for discriminative learning and related disorders.