Extinction-Reconsolidation Boundaries: Key to Persistent Attenuation of Fear Memories

  title={Extinction-Reconsolidation Boundaries: Key to Persistent Attenuation of Fear Memories},
  author={Marie H Monfils and Kiriana K. Cowansage and Eric Klann and Joseph E LeDoux},
  pages={951 - 955}
Reversing Pavlov Memories of fearful associations, such as hearing a tone before receiving a low-voltage shock, are labile when they are retrieved, such that the association can be extinguished or reconsolidated. Monfils et al. (p. 951, published online 2 April) demonstrate that applying a standard extinction treatment (sounding the tone multiple times in the absence of any shocks) within a window of time during which reconsolidation would normally occur has the effect of overwriting the… 
Updating Fearful Memories with Extinction Training during Reconsolidation: A Human Study Using Auditory Aversive Stimuli
This study replicated Schiller et al., (2010) behavioral manipulation and extended it to an auditory fear conditioning paradigm based on auditory aversive stimuli instead of electric shock and demonstrated that only the conditioned stimulus that was reminded 10 minutes before extinction training did not reinstate a fear response after a reminder trial consisting of the presentation of the unconditioned stimuli.
Extinction training during the reconsolidation window prevents recovery of fear.
This protocol addresses the transient nature of extinction by targeting the reconsolidation window to modify emotional memory in a more permanent manner by prompting fear memory retrieval prior to extinction, allowing new safety information to be incorporated while the fear memory is still susceptible to interference.
Extinction after retrieval: effects on the associative and nonassociative components of remote contextual fear memory.
It is shown that the reconsolidation-extinction procedure fails to prevent the spontaneous recovery of a remote contextual fear memory in a mouse model of PTSD, as well as the long-lasting behavioral abnormalities induced by traumatic experience on anxiety and in both social and cognitive domains.
Erasing fear memories — key receptor and essential timeframe discovered
It is suggested that removal of Ca2+-permeable-AMPARs, the content of which in the synapses is elevated for a few days after fear conditioning, is responsible for the permanent erasure of the fear memory by that protocol.
Effects of postretrieval-extinction learning on return of contextually controlled cued fear.
It is suggested that the use of fear-relevant stimuli, the context salience, or reactivation context may explain the lack of reconsolidation effect, and the beneficial effects of postretrieval-extinction learning are sensitive to subtle methodological changes.
Exposure to a fearful context during periods of memory plasticity impairs extinction via hyperactivation of frontal-amygdalar circuits.
The results show that long-term extinction is impaired when it occurs during time periods during which the memory should be most vulnerable to disruption (soon after conditioning or retrieval), and behavioral effects are correlated with hyperactivation of medial prefrontal cortex and amygdala subregions associated with fear expression rather than fear extinction.
Are fear memories erasable?–reconsolidation of learned fear with fear-relevant and fear-irrelevant stimuli
It is found that a single reminder exposure prior to extinction training did not prevent the return of extinguished fear responding using either fear-relevant or fear-irrelevant CSs, pointing to the need to further study the specific parameters that enable disruption of reconsolidation.
Retrieval and Reconsolidation Accounts of Fear Extinction
The findings suggest that strengthened extinction can result from alteration in both retrieval and consolidation processes, and is thought to open a period of memory vulnerability similar to that which occurs during initial consolidation.


Characterization of Fear Memory Reconsolidation
It is reported that reconsolidation cannot be reduced down to facilitated extinction and application of reminder shock does not result in the reinstatement of the memory, supporting the idea that reactivation of consolidated memories initiates a second time-dependent memory formation process.
Different mechanisms of fear extinction dependent on length of time since fear acquisition.
Data support a model in which different neural mechanisms are recruited depending on the temporal delay of fear extinction, and suggest that extinction initiated shortly following fear acquisition preferentially engages depotentiation/"unlearning," whereas extinction initiated at longer delays recruits a different mechanism.
Evidence for recovery of fear following immediate extinction in rats and humans.
Evidence is found for spontaneous recovery and reinstatement in both rats and humans even when extinction was conducted immediately after fear learning, which does not support the hypothesis that immediate extinction erases the original memory trace and suggests that a close temporal proximity of therapeutic intervention to the traumatic event might be advantageous.
Reconsolidation and Extinction of Conditioned Fear: Inhibition and Potentiation
Investigation of the effects of enhancing and blocking NMDA receptor-mediated glutamatergic transmission on the reconsolidation and extinction of a conditioned fear memory showed that the basolateral amygdala is a primary locus of action of systemically administered DCS, and memory reconsolidations can be both disrupted and enhanced.
Brain Region-Specific Gene Expression Activation Required for Reconsolidation and Extinction of Contextual Fear Memory
It is established that reactivated contextual fear memories undergo CREB-dependent reconsolidation or extinction in distinct brain regions.
Fear memories require protein synthesis in the amygdala for reconsolidation after retrieval
It is shown that consolidated fear memories, when reactivated during retrieval, return to a labile state in which infusion of anisomycin shortly after memory reactivation produces amnesia on later tests, regardless of whether reactivation was performed 1 or 14 days after conditioning.
Role of conditioned contextual stimuli in reinstatement of extinguished fear.
  • M. Bouton, R. Bolles
  • Psychology, Biology
    Journal of experimental psychology. Animal behavior processes
  • 1979
The results do not support the hypothesis that reinstatement results from an increment in the strength of a memory of the US that has been weakened during extinction, and problems inherent in controlling and detecting levels of context conditioning that may influence behavior toward nominal CSs are discussed.
Retrograde Amnesia Produced by Electroconvulsive Shock after Reactivation of a Consolidated Memory Trace
Rats had a memory loss of a fear response when they received an electroconvulsive shock 24 hours after the fear-conditioning trial and preceded by a brief presentation of the conditioned stimulus, which throws doubt on the assertion that electro Convulsive shock exerts a selective amnesic effect on recently acquired memories.
Recent fear is resistant to extinction
It is shown in an animal model of traumatic fear that early intervention shortly after an aversive experience yields poor long-term fear reduction, and that the level of fear present at the time of intervention is a critical factor in the efficacy of extinction.