An Update on Memory Reconsolidation Updating

Abstract

The reactivation of a stored memory in the brain can make the memory transiently labile. During the time it takes for the memory to restabilize (reconsolidate) the memory can either be reduced by an amnesic agent or enhanced by memory enhancers. The change in memory expression is related to changes in the brain correlates of long-term memory. Many have suggested that such retrieval-induced plasticity is ideally placed to enable memories to be updated with new information. This hypothesis has been tested experimentally, with a translational perspective, by attempts to update maladaptive memories to reduce their problematic impact. We review here progress on reconsolidation updating studies, highlighting their translational exploitation and addressing recent challenges to the reconsolidation field.

Keywords: addiction; counterconditioning; extinction; memory; reconsolidation; retrieval.

Fig. 1. The stages of reconsolidation updating

Experiencing a significant event may result in the formation of a long-term memory (in this case, an aversive emotional memory of a threatening dog). Encountering cues associated with the event (such as the red collar), may serve as a reminder that triggers the memory and destabilizes it. Re-stabilization (reconsolidation) of the memory ensues until the memory returns to a stable inactive state. During this time-window, update may occur in several possible ways, for example: extinction, counterconditioning, or interference. These processes may provide new information that is then incorporated into the memory (extinction, counterconditioning), or compete for resources and interfere with the memory’s re-storage, thereby hindering subsequent retrievals. The result is an updated memory, in this case devoid of the negative emotional response. In the case of drug-related memories, such updating may result in reduced drug craving. Reconsolidation updating in other memory systems might induce other alterations such as modified memory content. For example, new learning during reconsolidation of episodic memories can result in reduced or enhanced correct retrievals of the episodic items; and new learning during reconsolidation of motor memories can result in altered speed or accuracy of motor performance.