The idea that new memories undergo a time-dependent consolidation process after acquisition has received considerable experimental support. More controversial has been the demonstration that established memories, once recalled, become labile and sensitive to disruption, requiring "reconsolidation" to become permanent. By infusing antisense oligodeoxynucleotides into the hippocampus of rats, we show that consolidation and reconsolidation are doubly dissociable component processes of memory. Consolidation involves brain-derived neurotrophic factor (BDNF) but not the transcription factor Zif268, whereas reconsolidation recruits Zif268 but not BDNF. These findings confirm a requirement for BDNF specifically in memory consolidation and also resolve the role of Zif268 in brain plasticity, learning, and memory.
NMDA receptors are important for the acquisition, reconsolidation, and extinction of memories. NMDA receptor antagonists impair these memory processes, whereas the partial agonist D-cycloserine (DCS) potentiates both learning and extinction. Here, we used DCS and the noncompetitive NMDA receptor antagonist (ϩ)-5-methyl-10,11-dihydro-SH-dibenzo[a,d]cyclohepten-5,10-imine maleate (MK-801) to investigate the effects of enhancing and blocking NMDA receptor-mediated glutamatergic transmission on the reconsolidation and extinction of a conditioned fear memory. Either long extinction training or short memory reactivation sessions were used to preferentially engage extinction and reconsolidation processes, respectively. MK-801 blocked extinction to maintain high levels of conditioned freezing, and DCS potentiated extinction to reduce freezing, when they were administered before a long extinction training session. However, the opposite behavioral outcome was observed when the brief memory reactivation session was used: MK-801 administration impaired, whereas DCS increased, freezing, likely reflecting impairment and enhancement of reconsolidation, respectively. Finally, by using localized intracerebral infusions, we showed that the basolateral amygdala is a primary locus of action of systemically administered DCS. Thus, intrabasolateral amygdala DCS potentiated both the extinction and the reconsolidation of fear conditioning, depending on the length of the extinction/memory reactivation session. Therefore, memory reconsolidation can be both disrupted and enhanced, and extinction can be both potentiated and impaired, either to reduce or increase conditioned fear. These results have important implications for the use of reconsolidation blockade and potentiation of extinction as treatment strategies for maladaptive memory disorders.
The retrieval of a memory places it into a plastic state, as a result of which the memory can be disrupted or even enhanced by experimental treatment. This phenomenon has been conceptualised within a framework of memories being reactivated and then reconsolidated in repeated rounds of cellular processing. The reconsolidation phase has been seized upon as critical for the understanding of memory stability, and more recently as a potential therapeutic target in the treatment of disorders such as post-traumatic stress and drug addiction. However, little is known about the reactivation process, nor what might be the adaptive function of retrieval-induced plasticity. Reconsolidation has long been proposed to mediate memory updating, but only recently has this hypothesis been supported experimentally. Here, the adaptive function of memory reconsolidation is explored in more detail, with a strong emphasis on its role in updating memories to maintain their relevance.
The main objective of customer satisfaction programs is to increase customer retention rates. In explaining the link between customer satisfaction and loyalty, switching costs play an important role and provide useful insight. For example, the presence of switching costs can mean that some seemingly loyal customers are actually dissatisfied but do not defect because of high switching costs. Thus, the level of switching costs moderates the link between satisfaction and loyalty. The purposes of this paper are: to examine the moderating role of switching costs in the customer satisfaction‐loyalty link; and to identify customer segments and then analyze the heterogeneity in the satisfaction‐loyalty link among the different segments. An empirical example based on the mobile phone service market in France indicates support for the moderating role of switching costs. Managerial implications of the results are discussed.
Maladaptive memories that associate environmental stimuli with the effects of drugs of abuse are known to be a major cause of relapse to, and persistence of, a drug addictive habit. However, memories may be disrupted after their acquisition and consolidation by impairing their reconsolidation. Here, we show that infusion of Zif268 antisense oligodeoxynucleotides into the basolateral amygdala, prior to the reactivation of a well-learned memory for a conditioned stimulus (CS)-cocaine association, abolishes the acquired conditioned reinforcing properties of the drug-associated stimulus and thus its impact on the learning of a new cocaine-seeking response. Furthermore, we show that reconsolidation of CS-fear memories also requires Zif268 in the amygdala. These results demonstrate that appetitive CS-drug memories undergo reconsolidation in a manner similar to aversive memories and that this amygdala-dependent reconsolidation can be disrupted to reduce the impact of drug cues on drug seeking.
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