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Repeated Labilization-Reconsolidation Processes Strengthen Declarative Memory in Humans

By Cecilia Forcato, María L. C. Rodríguez and María E. Pedreira


The idea that memories are immutable after consolidation has been challenged. Several reports have shown that after the presentation of a specific reminder, reactivated old memories become labile and again susceptible to amnesic agents. Such vulnerability diminishes with the progress of time and implies a re-stabilization phase, usually referred to as reconsolidation. To date, the main findings describe the mechanisms associated with the labilization-reconsolidation process, but little is known about its functionality from a biological standpoint. Indeed, two functions have been proposed. One suggests that destabilization of the original memory after the reminder allows the integration of new information into the background of the original memory (memory updating), and the other suggests that the labilization-reconsolidation process strengthens the original memory (memory strengthening). We have previously reported the reconsolidation of human declarative memories, demonstrating memory updating in the framework of reconsolidation. Here we deal with the strengthening function attributed to the reconsolidation process. We triggered labilization-reconsolidation processes successively by repeated presentations of the proper reminder. Participants learned an association between five cue-syllables and their respective response-syllables. Twenty-four hours later, the paired-associate verbal memory was labilized by exposing the subjects to one, two or four reminders. The List-memory was evaluated on Day 3 showing that the memory was improved when at least a second reminder was presented in the time window of the first labilization-reconsolidation process prompted by the earlier reminder. However, the improvement effect was revealed on Day 3, only when at least two reminders were presented on Day2 and not as a consequence of only retrieval. Therefore, we propose central concepts for the reconsolidation process, emphasizing its biological role and the parametrical constrains for this function to be operative

Topics: Research Article
Publisher: Public Library of Science
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Provided by: PubMed Central

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  2. (2008). Activation of LVGCCs and CB1 receptors required for destabilization of reactivated contextual fear memories.
  3. (2004). Are spatial memories strengthened in the human hippocampus during slow wave sleep?
  4. (2002). Behavioral and neural analysis of extinction.
  5. (2009). Beyond extinction: erasing human fear responses and preventing the return of fear.
  6. (2004). Characterization of fear memory reconsolidation.
  7. (2002). Coordinated reactivation of distributed memory traces in primate neocortex.
  8. (2002). CREB required for the stability of new and reactivated fear memories.
  9. (2011). Delorenzi A
  10. Einarsson EO (2010) Memory reconsolidation: an update.
  11. (1972). Episodic and semantic memory.
  12. (2000). Fear memories require protein synthesis in the amygdala for reconsolidation after retrieval.
  13. (1977). Flashbulb memories.
  14. (2009). Human reconsolidation does not always occur when a memory is retrieved: the relevance of the reminder structure.
  15. (2004). Independent cellular processes for hippocampal memory consolidation and reconsolidation.
  16. (2011). Labile or stable: opposing consequences for memory when reactivated during waking and sleep.
  17. (2003). Learned material content and acquisition level modulate cerebral reactivation during posttraining rapid-eye-movements sleep.
  18. (2007). Maintaining memories by reactivation.
  19. (2006). Mechanisms of memory stabilization and de-stabilization.
  20. (2005). Mechanisms of memory stabilization: are consolidation and reconsolidation similar or distinct processes?
  21. (2002). Memory from A to Z. Keywords, Concepts and Beyond.
  22. (2004). Memory reconsolidation and extinction have distinct temporal and biochemical signatures.
  23. (2008). Memory reconsolidation mediates the strengthening of memories by additional learning.
  24. (2010). Memory reconsolidation mediates the updating of hippocampal memory content.
  25. (2006). Memory reconsolidation: sensitivity of spatial memory to inhibition of protein synthesis in dorsal hippocampus during encoding and retrieval.
  26. (2011). Memory retrieval and the passage of time: from reconsolidation and strengthening to extinction.
  27. (2000). Memory--a century of consolidation.
  28. (2004). Mismatch between what is expected and what actually occurs triggers memory reconsolidation or extinction.
  29. (2006). NMDA receptors are critical for unleashing consolidated auditory fear memories.
  30. (2007). Odor cues during slow-wave sleep prompt declarative memory consolidation.
  31. (2006). Offline persistence of memory-related cerebral activity during active wakefulness.
  32. (1900). Pilzecker A
  33. (2010). Preventing the return of fear in humans using reconsolidation update mechanisms.
  34. (1984). Protein synthesis and memory: a review.
  35. (2003). Protein synthesis subserves reconsolidation or extinction depending on reminder duration.
  36. (2005). Protein synthesis underlies post-retrieval memory consolidation to a restricted degree only when updated information is obtained.
  37. (1979). Psychobiology of active and inactive memory.
  38. (1999). Reactivation of hippocampal cell assemblies: effects of behavioral state, experience, and EEG dynamics.
  39. (2010). Reconsolidation in humans opens up declarative memory to the entrance of new information.
  40. (2007). Reconsolidation of declarative memory in humans.
  41. (2007). Reconsolidation of episodic memories: a subtle reminder triggers integration of new information.
  42. (2009). Reconsolidation: maintaining memory relevance.
  43. (2006). Reconsolidation: the advantage of being refocused.
  44. (2007). Reconsolidation: the samsara of memory consolidation.
  45. (2008). Regulatory mechanisms of fear extinction and depression-like behavior.
  46. (1932). Remembering: A study in Experimental and social Psychology. Mc Millan.
  47. (2000). Retrieval and reconsolidation: toward a neurobiology of remembering.
  48. (1995). Retrograde amnesia and memory consolidation: a neurobiological perspective.
  49. (1968). Retrograde amnesia produced by electroconvulsive shock after reactivation of a consolidated memory trace.
  50. (2008). Romano A
  51. (1978). Semantic integration of verbal information into a visual memory.
  52. (1971). Simple memory: a theory for archicortex.
  53. (2003). Stability of retrieved memory: inverse correlation with trace dominance.
  54. (2008). Synaptic protein degradation underlies destabilization of retrieved fear memory.
  55. (2002). Temporally graded requirement for protein synthesis following memory reactivation.
  56. (1998). The cognitive neuroscience of constructive memory.
  57. (2001). The consolidation of new but not reactivated memory requires hippocampal C/EBPbeta.
  58. (2001). The molecular biology of memory storage: a dialog between genes and synapses.
  59. (2004). The neurobiology of consolidations, or, how stable is the engram?
  60. (2007). The neuroscience of remote memory.
  61. (2005). The organization of recent and remote memories.
  62. (1966). Time-dependent processes in memory storage.
  63. (1996). Toward a molecular definition of longterm memory storage.
  64. (1982). Tulving E