Noradrenergic activation of the basolateral amygdala facilitates memory specificity for similar events experienced close in time

Noradrenergic activation of the basolateral amygdala (BLA) promotes strong and lasting memories of emotionally arousing experiences. However, in our lives, we often encounter similar events that may be confused and result in emotional strengthening of incorrect associations. Here we provide evidence, in rats, that noradrenergic activation of the BLA promotes the formation of discrete memories of similar events that were experienced close in time, via a miR-134-regulated consolidation process within the dentate gyrus of the hippocampus. Targeted downregulation of miR-134 in the hippocampus was sufficient to induce memory specificity, without affecting the strength of the memory. Notably, noradrenergic activation of the BLA did not recruit this hippocampal miR-134-mediated mechanism in enhancing memory of a single event. These findings indicate that the BLA engages a qualitatively different neural mechanism on an ‘as-needed’ basis to facilitate the separation of similar memory representations, enabling the selective strengthening of correct associations into long-term memory.