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Charpentier ANH, Olekanma DI, Valade CT, Reeves CA, Cho BR, Arguello AA. Influence of reconsolidation in maintenance of cocaine-associated contextual memories formed during adolescence or adulthood. Sci Rep 2023; 13:13936. [PMID: 37626103 PMCID: PMC10457301 DOI: 10.1038/s41598-023-39949-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 08/02/2023] [Indexed: 08/27/2023] Open
Abstract
Adolescents are at increased risk to develop substance use disorders and suffer from relapse throughout life. Targeted weakening of drug-associated memories has been shown to reduce relapse-like behavior in adult rats, however this process has been understudied in adolescents. We aimed to examine whether adolescent-formed, cocaine-associated memories could be manipulated via reconsolidation mechanisms. To accomplish this objective, we used an abbreviated operant cocaine self-administration paradigm (ABRV Coc-SA). Adult and adolescent rats received jugular catheterization surgery followed by ABRV Coc-SA in a distinct context for 2 h, 2×/day over 5 days. Extinction training (EXT) occurred in a second context for 2 h, 2×/day over 4 days. To retrieve cocaine-context memories, rats were exposed to the cocaine-paired context for 15 min, followed by subcutaneous injection of vehicle or the protein synthesis inhibitor cycloheximide (2.5 mg/kg). Two additional EXT sessions were conducted before a 2 h reinstatement test in the cocaine-paired context to assess cocaine-seeking behavior. We find that both adult and adolescent cocaine-exposed rats show similar levels of cocaine-seeking behavior regardless of post-reactivation treatment. Our results suggest that systemic treatment with the protein synthesis inhibitor cycloheximide does not impair reconsolidation of cocaine-context memories and subsequent relapse during adulthood or adolescence.
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Affiliation(s)
- André N Herrera Charpentier
- Department of Psychology, Behavioral Neuroscience, Michigan State University (MSU), Interdisciplinary Science and Technology Building, West Rm. 4010, 766 Service Rd., East Lansing, MI, 48824, USA
| | - Doris I Olekanma
- Department of Psychology, Behavioral Neuroscience, Michigan State University (MSU), Interdisciplinary Science and Technology Building, West Rm. 4010, 766 Service Rd., East Lansing, MI, 48824, USA
| | - Christian T Valade
- Department of Psychology, Behavioral Neuroscience, Michigan State University (MSU), Interdisciplinary Science and Technology Building, West Rm. 4010, 766 Service Rd., East Lansing, MI, 48824, USA
| | - Christopher A Reeves
- Department of Psychology, Behavioral Neuroscience, Michigan State University (MSU), Interdisciplinary Science and Technology Building, West Rm. 4010, 766 Service Rd., East Lansing, MI, 48824, USA
| | - Bo Ram Cho
- Department of Psychology, Behavioral Neuroscience, Michigan State University (MSU), Interdisciplinary Science and Technology Building, West Rm. 4010, 766 Service Rd., East Lansing, MI, 48824, USA
| | - Amy A Arguello
- Department of Psychology, Behavioral Neuroscience, Michigan State University (MSU), Interdisciplinary Science and Technology Building, West Rm. 4010, 766 Service Rd., East Lansing, MI, 48824, USA.
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2
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İlhan ÇF, Kışlal S. Memory Impairing Effect of Propranolol on Consolidation and Reconsolidation for Various Learning Tasks. Noro Psikiyatr Ars 2023; 60:271-282. [PMID: 37645086 PMCID: PMC10461772 DOI: 10.29399/npa.28203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Accepted: 07/06/2022] [Indexed: 08/31/2023] Open
Abstract
Newly acquired memory traces have been thought to become stable and resistant to interruption after they are stored in long-term memory. However, according to a recent research drugs such as beta-adrenergic receptor antagonists enable memories to be updated and rewritten when administered during consolidation and reconsolidation. Propranolol is a widely used beta-adrenergic receptor antagonist that disrupts the consolidation and reconsolidation processes of memory formation as it inhibits protein synthesis in the central nervous system. This review aims to discuss the memory impairing effect of the systemic and intracerebral administration of propranolol during the consolidation and reconsolidation processes associated with different learning tasks. In doing so, this review will help elucidate the effects of propranolol on different stages of memory formation. Since learning and maladaptive memories underpin some of the most common psychological disorders, such as phobias, post-traumatic stress disorder, addiction, drug-seeking behavior, and so on, a thorough understanding of propranolol's memory-impairing effect has significant clinical value and the potential to help people suffering from these disorders.
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Affiliation(s)
- Çınar Furkan İlhan
- Middle East Technical University, Institute of Social Sciences, Department of Psychology, Ankara, Turkey
| | - Sezen Kışlal
- Middle East Technical University, Institute of Social Sciences, Department of Psychology, Ankara, Turkey
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3
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Bui UTD, Milton AL. Making Leaps and Hitting Boundaries in Reconsolidation: Overcoming Boundary Conditions to Increase Clinical Translatability of Reconsolidation-based Therapies. Neuroscience 2023; 519:198-206. [PMID: 36933761 DOI: 10.1016/j.neuroscience.2023.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 03/03/2023] [Accepted: 03/11/2023] [Indexed: 03/18/2023]
Abstract
Reconsolidation results in the restabilisation, and thus persistence, of a memory made labile by retrieval, and interfering with this process is thought to enable modification or weakening of the original trace. As such, reconsolidation-blockade has been a focus of research aiming to target the maladaptive memories underlying mental health disorders, including post-traumatic stress disorder and drug addiction. Current first-line therapies are not effective for all patients, and a substantial proportion of those for whom therapies are effective later relapse. A reconsolidation-based intervention would be invaluable as an alternative treatment for these conditions. However, the translation of reconsolidation-based therapies to the clinic presents a number of challenges, with arguably the greatest being the overcoming of the boundary conditions governing the opening of the reconsolidation window. These include factors such as the age and strength of memory, and can broadly be divided into two categories: intrinsic features of the targeted memory itself, and parameters of the reactivation procedure used. With maladaptive memory characteristics inevitably varying amongst individuals, manipulation of the other limitations imposed by procedural variables have been explored to circumvent the boundary conditions on reconsolidation. Although several apparently discrepant results remain to be reconciled and these limitations yet to be truly defined, many studies have produced successful results which encouragingly demonstrate that boundary conditions may be overcome using various proposed strategies to enable translation of a reconsolidation-based intervention to clinical use.
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Affiliation(s)
- Uyen T D Bui
- Department of Psychology, University of Cambridge, UK
| | - Amy L Milton
- Department of Psychology, University of Cambridge, UK.
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4
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Barak S, Goltseker K. New Approaches for Alcohol Use Disorder Treatment via Memory Retrieval and Reconsolidation Manipulations. Curr Top Behav Neurosci 2023. [PMID: 36627475 DOI: 10.1007/7854_2022_411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Relapse to alcohol seeking and drinking is a major clinical challenge in alcohol use disorder and is frequently brought about by cue-induced craving, caused by exposure to cues that evoke alcohol-related memories. It has been postulated that memories become labile for manipulation shortly after their retrieval and then restabilize in a "memory reconsolidation" process. Disruption or interference with the reconsolidation of drug-associated memories has been suggested as a possible strategy to reduce or even prevent cue-induced craving and relapse. Here, we review literature demonstrating the capacity of behavioral or pharmacological manipulations to reduce relapse in animal models and humans when applied after a short retrieval of memories associated with alcohol, suggestively disrupting the reconsolidation of such memories. We suggest that while there is a clear potential of using post-retrieval manipulations to target specific relapse-evoking memories, future research should be more systematic, standardized, and translational. Specifically, we discuss several critical limitations and boundary conditions, which should be addressed to improve consistency and replicability in the field and lead to the development of an efficient reconsolidation-based relapse prevention therapy.
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Affiliation(s)
- Segev Barak
- School of Psychological Sciences, Tel Aviv University, Tel Aviv, Israel.
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
| | - Koral Goltseker
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
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5
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Cain CK. Beyond Fear, Extinction, and Freezing: Strategies for Improving the Translational Value of Animal Conditioning Research. Curr Top Behav Neurosci 2023; 64:19-57. [PMID: 37532965 PMCID: PMC10840073 DOI: 10.1007/7854_2023_434] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2023]
Abstract
Translational neuroscience for anxiety has had limited success despite great progress in understanding the neurobiology of Pavlovian fear conditioning and extinction. This chapter explores the idea that conditioning paradigms have had a modest impact on translation because studies in animals and humans are misaligned in important ways. For instance, animal conditioning studies typically use imminent threats to assess short-duration fear states with single behavioral measures (e.g., freezing), whereas human studies typically assess weaker or more prolonged anxiety states with physiological (e.g., skin conductance) and self-report measures. A path forward may be more animal research on conditioned anxiety phenomena measuring dynamic behavioral and physiological responses in more complex environments. Exploring transitions between defensive brain states during extinction, looming threats, and post-threat recovery may be particularly informative. If care is taken to align paradigms, threat levels, and measures, this strategy may reveal stable patterns of non-conscious defense in animals and humans that correlate better with conscious anxiety. This shift in focus is also warranted because anxiety is a bigger problem than fear, even in disorders defined by dysfunctional fear or panic reactions.
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Affiliation(s)
- Christopher K Cain
- Department of Child and Adolescent Psychiatry, NYU Langone Health, New York, NY, USA.
- Emotional Brain Institute, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA.
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6
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Wang SH. Lose the fear and boost the everyday memory through memory destabilisation and reconsolidation. Brain Res Bull 2022; 190:134-139. [DOI: 10.1016/j.brainresbull.2022.09.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 09/12/2022] [Accepted: 09/24/2022] [Indexed: 11/02/2022]
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Batashvili M, Sheaffer R, Katz M, Doron Y, Kempler N, Levy DA. Behavioural reconsolidation interference not observed in a within-subjects design. NPJ SCIENCE OF LEARNING 2022; 7:26. [PMID: 36220898 PMCID: PMC9553081 DOI: 10.1038/s41539-022-00143-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
Studies of reconsolidation interference posit that reactivation of a previously consolidated memory via a reminder brings it into an active, labile state, leaving it open for potential manipulation. If interfered with, this may disrupt the original memory trace. While evidence for pharmacological reconsolidation interference is widespread, it remains unclear whether behavioural interference using the presentation of competing information can engender it, especially in declarative memory. Almost all previous studies in this area have employed between-subjects designs, in which there are potential confounds, such as different retrieval strategies for the multiple conditions. In the current studies, within-subjects paradigms were applied to test the effects of reconsolidation interference on associative recognition and free recall. In Experiment 1, participants engaged in pair-associate learning of unrelated object pictures on Day 1, and after a reminder, interference, reminder + interference, or no manipulation (control) on Day 2, were tested on associative recognition of these pairs on Day 3. In Experiments 2 and 3, memoranda were short stories studied on Day 1. On Day 2, stories were assigned to either control, reminder, interference by alternative stories, or reminder + interference conditions. On Day 3 participants recalled the Day 1 stories, and answered yes/no recognition questions. Reminders improved subsequent memory, while interference was effective in reducing retrieval in differing degrees across the experiments. Importantly, the reminder + interference condition was no more effective in impairing retrieval than the interference-alone condition, contrary to the prediction of the behavioural reconsolidation-interference approach.
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Affiliation(s)
- Michael Batashvili
- Baruch Ivcher School of Psychology, Reichman University, Herzliya, Israel
| | - Rona Sheaffer
- Baruch Ivcher School of Psychology, Reichman University, Herzliya, Israel
| | - Maya Katz
- Baruch Ivcher School of Psychology, Reichman University, Herzliya, Israel
| | - Yoav Doron
- Baruch Ivcher School of Psychology, Reichman University, Herzliya, Israel
| | - Noam Kempler
- Baruch Ivcher School of Psychology, Reichman University, Herzliya, Israel
| | - Daniel A Levy
- Baruch Ivcher School of Psychology, Reichman University, Herzliya, Israel.
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8
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Appraising reconsolidation theory and its empirical validation. Psychon Bull Rev 2022; 30:450-463. [PMID: 36085236 PMCID: PMC7614440 DOI: 10.3758/s13423-022-02173-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2022] [Indexed: 11/08/2022]
Abstract
Re-exposure to elements of prior experiences can create opportunities for inducing amnesia for those events. The dominant theoretical framework posits that such re-exposure can result in memory destabilization, making the memory representation temporarily sensitive to disruption while it awaits reconsolidation. If true, such a mechanism that allows for memories to be permanently changed could have important implications for the treatment of several forms of psychopathology. However, there have been contradictory findings and elusive occurrences of replication failures within the "reconsolidation" field. Considering its potential relevance for clinical applications, the fact that this "hot" research area is being dominated by a single mechanistic theory, and the presence of unexplainable contradictory findings, we believe that it is both useful and timely to critically evaluate the reconsolidation framework. We discuss potential issues that may arise from how reconsolidation interference has typically been deducted from behavioral observations, and provide a principled assessment of reconsolidation theory that illustrates that the theory and its proposed boundary conditions are vaguely defined, which has made it close to impossible to refute reconsolidation theory. We advocate for caution, encouraging researchers not to blindly assume that a reconsolidation process must underlie their findings, and pointing out the risks of doing so. Finally, we suggest concrete theoretical and methodological advances that can promote a fruitful translation of reminder-dependent amnesia into clinical treatment.
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9
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Cox WR, Faliagkas L, Besseling A, van der Loo RJ, Spijker S, Kindt M, Rao-Ruiz P. Interfering With Contextual Fear Memories by Post-reactivation Administration of Propranolol in Mice: A Series of Null Findings. Front Behav Neurosci 2022; 16:893572. [PMID: 35832291 PMCID: PMC9272000 DOI: 10.3389/fnbeh.2022.893572] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 05/18/2022] [Indexed: 11/13/2022] Open
Abstract
Post-reactivation amnesia of contextual fear memories by blockade of noradrenergic signaling has been shown to have limited replicability in rodents. This is usually attributed to several boundary conditions that gate the destabilization of memory during its retrieval. How these boundary conditions can be overcome, and what neural mechanisms underlie post-reactivation changes in contextual fear memories remain largely unknown. Here, we report a series of experiments in a contextual fear-conditioning paradigm in mice, that were aimed at solving these issues. We first attempted to obtain a training paradigm that would consistently result in contextual fear memory that could be destabilized upon reactivation, enabling post-retrieval amnesia by the administration of propranolol. Unexpectedly, our attempts were unsuccessful to this end. Specifically, over a series of experiments in which we varied different parameters of the fear acquisition procedure, at best small and inconsistent effects were observed. Additionally, we found that propranolol did not alter retrieval-induced neural activity, as measured by the number of c-Fos+ cells in the hippocampal dentate gyrus. To determine whether propranolol was perhaps ineffective in interfering with reactivated contextual fear memories, we also included anisomycin (i.e., a potent and well-known amnesic drug) in several experiments, and measures of synaptic glutamate receptor subunit GluA2 (i.e., a marker of memory destabilization). No post-retrieval amnesia by anisomycin and no altered GluA2 expression by reactivation was observed, suggesting that the memories did not undergo destabilization. The null findings are surprising, given that the training paradigms we implemented were previously shown to result in memories that could be modified upon reactivation. Together, our observations illustrate the elusive nature of reactivation-dependent changes in non-human fear memory.
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Affiliation(s)
- Wouter R. Cox
- Department of Psychology, Clinical Psychology, University of Amsterdam, Amsterdam, Netherlands
| | - Leonidas Faliagkas
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Amber Besseling
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Rolinka J. van der Loo
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Sabine Spijker
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Merel Kindt
- Department of Psychology, Clinical Psychology, University of Amsterdam, Amsterdam, Netherlands
| | - Priyanka Rao-Ruiz
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
- *Correspondence: Priyanka Rao-Ruiz
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10
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Jardine KH, Huff AE, Wideman CE, McGraw SD, Winters BD. The evidence for and against reactivation-induced memory updating in humans and nonhuman animals. Neurosci Biobehav Rev 2022; 136:104598. [PMID: 35247380 DOI: 10.1016/j.neubiorev.2022.104598] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 02/28/2022] [Accepted: 03/01/2022] [Indexed: 12/31/2022]
Abstract
Systematic investigation of reactivation-induced memory updating began in the 1960s, and a wave of research in this area followed the seminal articulation of "reconsolidation" theory in the early 2000s. Myriad studies indicate that memory reactivation can cause previously consolidated memories to become labile and sensitive to weakening, strengthening, or other forms of modification. However, from its nascent period to the present, the field has been beset by inconsistencies in researchers' abilities to replicate seemingly established effects. Here we review these many studies, synthesizing the human and nonhuman animal literature, and suggest that these failures-to-replicate reflect a highly complex and delicately balanced memory modification system, the substrates of which must be finely tuned to enable adaptive memory updating while limiting maladaptive, inaccurate modifications. A systematic approach to the entire body of evidence, integrating positive and null findings, will yield a comprehensive understanding of the complex and dynamic nature of long-term memory storage and the potential for harnessing modification processes to treat mental disorders driven by pervasive maladaptive memories.
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Affiliation(s)
- Kristen H Jardine
- Department of Psychology and Collaborative Neuroscience Program, University of Guelph, Guelph, ON, Canada
| | - A Ethan Huff
- Department of Psychology and Collaborative Neuroscience Program, University of Guelph, Guelph, ON, Canada
| | - Cassidy E Wideman
- Department of Psychology and Collaborative Neuroscience Program, University of Guelph, Guelph, ON, Canada
| | - Shelby D McGraw
- Department of Psychology and Collaborative Neuroscience Program, University of Guelph, Guelph, ON, Canada
| | - Boyer D Winters
- Department of Psychology and Collaborative Neuroscience Program, University of Guelph, Guelph, ON, Canada.
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11
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Rotondo F, Biddle K, Chen J, Ferencik J, d'Esneval M, Milton AL. Lack of Effect of Propranolol on the Reconsolidation of Conditioned Fear Memory due to a Failure to Engage Memory Destabilisation. Neuroscience 2021; 480:9-18. [PMID: 34774713 DOI: 10.1016/j.neuroscience.2021.11.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 10/27/2021] [Accepted: 11/02/2021] [Indexed: 12/21/2022]
Abstract
The prospect of exploiting memory reconsolidation to treat mental health disorders has received great research interest, particularly following demonstrations that the β-adrenergic receptor antagonist propranolol, which is safe for use in humans, can disrupt the reconsolidation of pavlovian conditioned fear memories. However, recent studies have failed to replicate the effects of propranolol on fear memory reconsolidation, and have questioned whether treatments based upon reconsolidation blockade would be robust enough for clinical translation. It remains possible, though, that studies reporting no effect of propranolol on memory reconsolidation could be due to a failure to engage the memory destabilisation process, which is necessary for the memory to become susceptible to disruption with amnestic agents. Demonstrating that memory destabilisation has not been engaged is challenging when only using behavioural measures, but there are molecular correlates of memory destabilisation that can be used to determine whether memory lability has been induced. Here, we attempted to replicate the classic finding that systemic administration of propranolol disrupts the reconsolidation of a pavlovian auditory fear memory. Following a failure to replicate, we manipulated the parameters of the memory reactivation session to enhance prediction error in an attempt to overcome the boundary conditions of reconsolidation. On finding no disruption of memory despite these manipulations, we examined the expression of the post-synaptic density protein Shank in the basolateral amygdala. Degradation of Shank has been shown to correlate with the induction of memory lability, but we found no effect on Shank expression, consistent with the lack of observed behavioural effects.
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Affiliation(s)
- Federico Rotondo
- Department of Life Sciences, University of Trieste, Via Licio Giorgieri, 5, 34127 Trieste, TS, Italy
| | - Kathryn Biddle
- Department of Psychology, University of Cambridge, Downing Site, Cambridge, UK
| | - John Chen
- Department of Psychology, University of Cambridge, Downing Site, Cambridge, UK
| | - Josh Ferencik
- Department of Psychology, University of Cambridge, Downing Site, Cambridge, UK
| | - Mathilde d'Esneval
- Department of Psychology, University of Cambridge, Downing Site, Cambridge, UK; Department of Neurology, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, 2105 Geneva, Switzerland
| | - Amy L Milton
- Department of Psychology, University of Cambridge, Downing Site, Cambridge, UK.
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12
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Covert capture and attenuation of a hippocampus-dependent fear memory. Nat Neurosci 2021; 24:677-684. [PMID: 33795883 PMCID: PMC8102347 DOI: 10.1038/s41593-021-00825-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 02/22/2021] [Indexed: 01/30/2023]
Abstract
Reconsolidation may be a viable therapeutic target to inhibit pathological fear memories. In the clinic, incidental or imaginal reminders are used for safe retrieval of traumatic memories of experiences that occurred elsewhere. However, it is unknown whether indirectly retrieved traumatic memories are sensitive to disruption. Here we used a backward (BW) conditioning procedure to indirectly retrieve and manipulate a hippocampus (HPC)-dependent contextual fear engram in male rats. We show that conditioned freezing to a BW conditioned stimulus (CS) is mediated by fear to the conditioning context, activates HPC ensembles that can be covertly captured and chemogenetically activated to drive fear, and is impaired by post-retrieval protein synthesis inhibition. These results reveal that indirectly retrieved contextual fear memories reactivate HPC ensembles and undergo protein synthesis-dependent reconsolidation. Clinical interventions that rely on indirect retrieval of traumatic memories, such as imaginal exposure, may open a window for editing or erasure of neural representations that drive pathological fear.
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13
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Targeting the Reconsolidation of Licit Drug Memories to Prevent Relapse: Focus on Alcohol and Nicotine. Int J Mol Sci 2021; 22:ijms22084090. [PMID: 33920982 PMCID: PMC8071281 DOI: 10.3390/ijms22084090] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 04/11/2021] [Accepted: 04/12/2021] [Indexed: 12/29/2022] Open
Abstract
Alcohol and nicotine are widely abused legal substances worldwide. Relapse to alcohol or tobacco seeking and consumption after abstinence is a major clinical challenge, and is often evoked by cue-induced craving. Therefore, disruption of the memory for the cue–drug association is expected to suppress relapse. Memories have been postulated to become labile shortly after their retrieval, during a “memory reconsolidation” process. Interference with the reconsolidation of drug-associated memories has been suggested as a possible strategy to reduce or even prevent cue-induced craving and relapse. Here, we surveyed the growing body of studies in animal models and in humans assessing the effectiveness of pharmacological or behavioral manipulations in reducing relapse by interfering with the reconsolidation of alcohol and nicotine/tobacco memories. Our review points to the potential of targeting the reconsolidation of these memories as a strategy to suppress relapse to alcohol drinking and tobacco smoking. However, we discuss several critical limitations and boundary conditions, which should be considered to improve the consistency and replicability in the field, and for development of an efficient reconsolidation-based relapse-prevention therapy.
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14
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Reactivation-Dependent Amnesia for Contextual Fear Memories: Evidence for Publication Bias. eNeuro 2021; 8:ENEURO.0108-20.2020. [PMID: 33355289 PMCID: PMC7877470 DOI: 10.1523/eneuro.0108-20.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 11/27/2020] [Accepted: 12/02/2020] [Indexed: 12/14/2022] Open
Abstract
Research on memory reconsolidation has been booming in the last two decades, with numerous high-impact publications reporting promising amnestic interventions in rodents and humans. However, our own recently-published failed replication attempts of reactivation-dependent amnesia for fear memories in rats suggest that such amnestic effects are not always readily found and that they depend on subtle and possibly uncontrollable parameters. The discrepancy between our observations and published studies in rodents suggests that the literature in this field might be biased. The aim of the current study was to gauge the presence of publication bias in a well-delineated part of the reconsolidation literature. To this end, we performed a systematic review of the literature on reactivation-dependent amnesia for contextual fear memories in rodents, followed by a statistical assessment of publication bias in this sample. In addition, relevant researchers were contacted for unpublished results, which were included in the current analyses. The obtained results support the presence of publication bias, suggesting that the literature provides an overly optimistic overall estimate of the size and reproducibility of amnestic effects. Reactivation-dependent amnesia for contextual fear memories in rodents is thus less robust than what is projected by the literature. The moderate success of clinical studies may be in line with this conclusion, rather than reflecting translational issues. For the field to evolve, replication and non-biased publication of obtained results are essential. A set of tools that can create opportunities to increase transparency, reproducibility and credibility of research findings is provided.
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