Npas4-mediated dopaminergic regulation of memory states

Abstract

Amygdala circuitry encodes associations between conditioned stimuli and unconditioned stimuli, and also controls fear expression. However, whether and how non-threatening information for unpaired conditioned stimuli (CS-) is discretely processed remains unknown. Immediately after fear conditioning, the mice showed robust fear expression toward CS-, but becomes negligible after memory consolidation. The synaptic plasticity of neural pathway from the lateral amygdala (LA) to the anterior basal amygdala (aBA) gates the fear expression of CS- depending upon Npas4-Drd4 axis, which is precluded by stress exposure or enhanced corticosterone level. Moreover, a subset of LA neurons, which expressed Npas4, regulates the state of CS- memory to be remained silent. In here, we show cellular and molecular mechanisms regulating the non-threatening memory consolidation which supports the fear discrimination.