Publications by authors named "Elizaveta V Muravieva"

3 Publications

  • Page 1 of 1

Memory retrieval and the passage of time: from reconsolidation and strengthening to extinction.

J Neurosci 2011 Feb;31(5):1635-43

Department of Neuroscience, Mount Sinai School of Medicine, New York, New York, 10029, USA.

An established memory can be made transiently labile if retrieved or reactivated. Over time, it becomes again resistant to disruption and this process that renders the memory stable is termed reconsolidation. The reasons why a memory becomes labile after retrieval and reconsolidates still remains debated. Here, using inhibitory avoidance learning in rats, we provide evidence that retrievals of a young memory, which are accompanied by its reconsolidation, result in memory strengthening and contribute to its overall consolidation. This function associated to reconsolidation is temporally limited. With the passage of time, the stored memory undergoes important changes, as revealed by the behavioral outcomes of its retrieval. Over time, without explicit retrievals, memory first strengthens and becomes refractory to both retrieval-dependent interference and strengthening. At later times, the same retrievals that lead to reconsolidation of a young memory extinguish an older memory. We conclude that the storage of information is very dynamic and that its temporal evolution regulates behavioral outcomes. These results are important for potential clinical applications.
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http://dx.doi.org/10.1523/JNEUROSCI.4736-10.2011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3069643PMC
February 2011

Disrupting the memory of places induced by drugs of abuse weakens motivational withdrawal in a context-dependent manner.

Proc Natl Acad Sci U S A 2010 Jul 21;107(27):12345-50. Epub 2010 Jun 21.

Departments of Neuroscience, Mount Sinai School of Medicine, New York, NY 10029, USA.

Addicts repeatedly relapse to drug seeking even after years of abstinence, and this behavior is frequently induced by the recall of memories of the rewarding effects of the drug. Established memories, including those induced by drugs of abuse, can become transiently fragile if reactivated, and during this labile phase, known as reconsolidation, can be persistently disrupted. Here we show that, in rats, a morphine-induced place preference (mCPP) memory is linked to context-dependent withdrawal as disrupting the reconsolidation of the memory leads to a significant reduction of withdrawal evoked in the same context. Moreover, the hippocampus plays a critical role in linking the place preference memory with the context-conditioned withdrawal, as disrupting hippocampal protein synthesis and cAMP-dependent-protein kinase A after the reactivation of mCPP significantly weakens the withdrawal. Hence, targeting memories induced by drugs may represent an important strategy for attenuating context-conditioned withdrawal and therefore subsequent relapse in opiate addicts.
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http://dx.doi.org/10.1073/pnas.1003152107DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2901477PMC
July 2010

Limited efficacy of propranolol on the reconsolidation of fear memories.

Learn Mem 2010 Jun 1;17(6):306-13. Epub 2010 Jun 1.

Department of Neuroscience, Mount Sinai School of Medicine, New York, New York 10029, USA.

Previous studies suggested that the beta-adrenergic receptor antagonist propranolol might be a novel, potential treatment for post-traumatic stress disorder (PTSD). This hypothesis stemmed mainly from rodent studies showing that propranolol interferes with the reconsolidation of Pavlovian fear conditioning (FC). However, subsequent investigations in humans have produced controversial evidence about the effect of propranolol on fear memories and an effect on PTSD symptomatology has yet to be reported. Thus, it remains to be established whether propranolol interferes with the reconsolidation of fear memories at large. To address this question, we tested the effect of systemic injections of propranolol administered before or after the retrieval of an inhibitory avoidance (IA) memory elicited with different footshock intensities. In parallel, the same treatment was tested on the reconsolidation of Pavlovian FC. Propranolol showed no effect on the reconsolidation of IA, although the pre-retrieval administration resulted in a significant retrieval impairment. This impairment was transient, and memory returned to control levels at later times. In agreement with previous studies, we found that systemic administration of propranolol disrupts the reconsolidation of Pavlovian FC and that its injection following a retrieval elicited by cue exposure also interferes with the reconsolidation of contextual FC. Hence, propranolol disrupts the reconsolidation of Pavlovian FC, but has no effect on the reconsolidation of IA. The results indicate that the efficacy of systemic administration of propranolol in disrupting the reconsolidation of fear memories is limited.
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http://dx.doi.org/10.1101/lm.1794710DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2884288PMC
June 2010