Noradrenergic Signaling in the Amygdala Contributes to the Reconsolidation of Fear Memory

Intrusive memories resulting from an emotional trauma are a defining feature of posttraumatic stress disorder (PTSD). Existing studies demonstrate that an increase of noradrenergic activity during a life-threatening event contributes to strengthening or "overconsolidation" of the memory for trauma. The lateral nucleus of the amygdala (LA) is critical for fear learning. Using classical fear conditioning in rats, we have recently demonstrated that noradrenergic blockade in the LA following reactivation of fear memory by retrieval disrupts memory reconsolidation and lastingly impairs fear memory. This suggests that noradrenergic blockade may be useful in attenuating traumatic memories, even well-consolidated old memories, in PTSD.