Disrupting reconsolidation: memory erasure or blunting of emotional/motivational value?

Neuropsychopharmacology. 2019 Jan;44(2):399-407. doi: 10.1038/s41386-018-0082-0. Epub 2018 May 3.

Abstract

When memories are retrieved they become labile, and subject to alteration by a process known as reconsolidation. Disruption of memory reconsolidation decreases the performance of learned responses, which is often attributed to erasure of the memory; in the case of Pavlovian learning, to a loss of the association between a conditioned stimulus (CS) and unconditioned stimulus (US). However, an alternative interpretation is that disrupting reconsolidation does not erase memories, but blunts their emotional/motivational impact. It is difficult to parse the predictive vs. emotional/motivational value of CSs in non-human animals, but studies on variation in the form of conditioned responses (CRs) in a Pavlovian conditioned approach task suggest a way to do this. In this task a lever-CS paired with a food reward (US) acquires predictive value in all rats, but is attributed with emotional/motivational value to a greater extent in some rats (sign-trackers) than others (goal-trackers). We report that the post-retrieval administration of propranolol selectively attenuates a sign-tracking CR, and the associated neural activation of brain "motive circuits", while having no effect on conditioned orienting behavior in sign-trackers, or on goal-tracking CRs evoked by either a lever-CS or a tone-CS. We conclude that the disruption of reconsolidation by post-retrieval propranolol degrades the emotional/motivational impact of the CS, required for sign-tracking, but leaves the CS-US association intact. The possibility that post-retrieval interventions can reduce the emotional/motivational aspects of memories, without actually erasing them, has important implications for treating maladaptive memories that contribute to some psychiatric disorders.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adrenergic beta-Antagonists / pharmacology*
  • Animals
  • Conditioning, Classical / drug effects*
  • Cues
  • Emotions / drug effects*
  • Male
  • Memory Consolidation / drug effects*
  • Motivation / drug effects*
  • Nadolol / pharmacology
  • Propranolol / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • Reward

Substances

  • Adrenergic beta-Antagonists
  • Nadolol
  • Propranolol