Npas4-mediated regulation of irrelevant memory in the amygdala

Abstract

The amygdala plays an essential role in associations between conditioned stimuli and aversive unconditioned stimuli, and regulates conditioned fear responses. However, the mechanism of irrelevant memory for unpaired conditioned stimuli (CS-) has not been investigated. Here, we show that irrelevant memory is regulated by the expression of Npas4 (Neuronal PAS domain protein 4) and the neurons in which it was expressed. Npas4-expressing neurons have a minimal overlap rate with c-Fos-expressing neurons, and encode different memory. c-Fos-expressing neurons regulate conditioned fear memory, not irrelevant memory. Our study suggests that Npas4 in the amygdala regulates irrelevant memory and shows a distinct role that is different from c-Fos during fear memory formation.