Extinction is not a sufficient condition to prevent fear memories from undergoing reconsolidation in the basolateral amygdala

Consolidated memories when reactivated may return to a state that requires protein synthesis in order to be restabilized (reconsolidation). It has been shown in a variety of systems that if reactivation induces significant extinction then extinction is the protein synthesis dependent memory state, rather than reconsolidation. Thus, extinction consolidation may prevent the memory from undergoing reconsolidation. We investigated whether such an interaction also exists between extinction and reconsolidation of fear memories within the amygdala, by using a within subjects experimental design. We found that inhibition of protein synthesis in the basolateral amygdala (BLA) impaired reconsolidation for both the briefly reactivated and extinguished fear memories suggesting that extinction is not a sufficient condition to prevent induction of reconsolidation in the amygdala. These findings demonstrate that extinction consolidation does not always interact with reconsolidation. Therefore, under these conditions, extinction is not a boundary condition on reconsolidation of fear memories in the basolateral amygdala.