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Roy DS, Kitamura T, Okuyama T, Ogawa SK, Sun C, Obata Y, Yoshiki A, Tonegawa S. Distinct Neural Circuits for the Formation and Retrieval of Episodic Memories. Cell 2017; 170:1000-1012.e19. [PMID: 28823555 PMCID: PMC5586038 DOI: 10.1016/j.cell.2017.07.013] [Citation(s) in RCA: 165] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Revised: 03/01/2017] [Accepted: 07/12/2017] [Indexed: 01/26/2023]
Abstract
The formation and retrieval of a memory is thought to be accomplished by activation and reactivation, respectively, of the memory-holding cells (engram cells) by a common set of neural circuits, but this hypothesis has not been established. The medial temporal-lobe system is essential for the formation and retrieval of episodic memory for which individual hippocampal subfields and entorhinal cortex layers contribute by carrying out specific functions. One subfield whose function is poorly known is the subiculum. Here, we show that dorsal subiculum and the circuit, CA1 to dorsal subiculum to medial entorhinal cortex layer 5, play a crucial role selectively in the retrieval of episodic memories. Conversely, the direct CA1 to medial entorhinal cortex layer 5 circuit is essential specifically for memory formation. Our data suggest that the subiculum-containing detour loop is dedicated to meet the requirements associated with recall such as rapid memory updating and retrieval-driven instinctive fear responses.
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Affiliation(s)
- Dheeraj S Roy
- RIKEN-MIT Center for Neural Circuit Genetics at the Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Takashi Kitamura
- RIKEN-MIT Center for Neural Circuit Genetics at the Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Teruhiro Okuyama
- RIKEN-MIT Center for Neural Circuit Genetics at the Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Sachie K Ogawa
- RIKEN-MIT Center for Neural Circuit Genetics at the Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Chen Sun
- RIKEN-MIT Center for Neural Circuit Genetics at the Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Yuichi Obata
- RIKEN BioResource Center, 3-1-1 Koyadai, Ibaraki 305-0074, Japan
| | - Atsushi Yoshiki
- RIKEN BioResource Center, 3-1-1 Koyadai, Ibaraki 305-0074, Japan
| | - Susumu Tonegawa
- RIKEN-MIT Center for Neural Circuit Genetics at the Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan.
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52
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Heroux NA, Robinson-Drummer PA, Sanders HR, Rosen JB, Stanton ME. Differential involvement of the medial prefrontal cortex across variants of contextual fear conditioning. ACTA ACUST UNITED AC 2017; 24:322-330. [PMID: 28716952 PMCID: PMC5516685 DOI: 10.1101/lm.045286.117] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 05/12/2017] [Indexed: 11/24/2022]
Abstract
The context preexposure facilitation effect (CPFE) is a contextual fear conditioning paradigm in which learning about the context, acquiring the context-shock association, and retrieving/expressing contextual fear are temporally dissociated into three distinct phases. In contrast, learning about the context and the context-shock association happens concurrently in standard contextual fear conditioning (sCFC). By infusing the GABAA receptor agonist muscimol into medial prefrontal cortex (mPFC) in adolescent Long-Evans rats, the current set of experiments examined the functional role of the mPFC in each phase of the CPFE and sCFC. In the CPFE, the mPFC is necessary for the following: acquisition and/or consolidation of context memory (Experiment 1), reconsolidation of a context memory to include shock (Experiment 2), and expression of contextual fear memory during a retention test (Experiment 3). In contrast to the CPFE, inactivation of the mPFC prior to conditioning in sCFC has no effect on acquisition, consolidation, or retention of a contextual fear memory (Experiment 4). Interestingly, the mPFC is not required for acquiring a context-shock association (measured by post-shock freezing) in the CPFE or sCFC (Experiment 2b and 4). Taken together, these results indicate that the mPFC is differentially recruited across stages of learning and variants of contextual fear conditioning (CPFE versus sCFC). More specifically, separating out learning about the context and the context-shock association necessitates activation of the medial prefrontal cortex during early learning and/or consolidation.
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Affiliation(s)
- Nicholas A Heroux
- Department of Psychological and Brain Sciences, University of Delaware, Newark, Delaware 19716, USA
| | | | - Hollie R Sanders
- Department of Psychological and Brain Sciences, University of Delaware, Newark, Delaware 19716, USA
| | - Jeffrey B Rosen
- Department of Psychological and Brain Sciences, University of Delaware, Newark, Delaware 19716, USA
| | - Mark E Stanton
- Department of Psychological and Brain Sciences, University of Delaware, Newark, Delaware 19716, USA
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53
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Kwapis JL, Jarome TJ, Ferrara NC, Helmstetter FJ. Updating Procedures Can Reorganize the Neural Circuit Supporting a Fear Memory. Neuropsychopharmacology 2017; 42:1688-1697. [PMID: 28139682 PMCID: PMC5518901 DOI: 10.1038/npp.2017.23] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 01/23/2017] [Accepted: 01/24/2017] [Indexed: 11/08/2022]
Abstract
Established memories undergo a period of vulnerability following retrieval, a process termed 'reconsolidation.' Recent work has shown that the hypothetical process of reconsolidation is only triggered when new information is presented during retrieval, suggesting that this process may allow existing memories to be modified. Reconsolidation has received increasing attention as a possible therapeutic target for treating disorders that stem from traumatic memories, yet little is known about how this process changes the original memory. In particular, it is unknown whether reconsolidation can reorganize the neural circuit supporting an existing memory after that memory is modified with new information. Here, we show that trace fear memory undergoes a protein synthesis-dependent reconsolidation process following exposure to a single updating trial of delay conditioning. Further, this reconsolidation-dependent updating process appears to reorganize the neural circuit supporting the trace-trained memory, so that it better reflects the circuit supporting delay fear. Specifically, after a trace-to-delay update session, the amygdala is now required for extinction of the updated memory but the retrosplenial cortex is no longer required for retrieval. These results suggest that updating procedures could be used to force a complex, poorly defined memory circuit to rely on a better-defined neural circuit that may be more amenable to behavioral or pharmacological manipulation. This is the first evidence that exposure to new information can fundamentally reorganize the neural circuit supporting an existing memory.
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Affiliation(s)
- Janine L Kwapis
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Timothy J Jarome
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Nicole C Ferrara
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Fred J Helmstetter
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
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54
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Lee JLC, Nader K, Schiller D. An Update on Memory Reconsolidation Updating. Trends Cogn Sci 2017; 21:531-545. [PMID: 28495311 DOI: 10.1016/j.tics.2017.04.006] [Citation(s) in RCA: 292] [Impact Index Per Article: 41.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 04/12/2017] [Accepted: 04/13/2017] [Indexed: 10/19/2022]
Abstract
The reactivation of a stored memory in the brain can make the memory transiently labile. During the time it takes for the memory to restabilize (reconsolidate) the memory can either be reduced by an amnesic agent or enhanced by memory enhancers. The change in memory expression is related to changes in the brain correlates of long-term memory. Many have suggested that such retrieval-induced plasticity is ideally placed to enable memories to be updated with new information. This hypothesis has been tested experimentally, with a translational perspective, by attempts to update maladaptive memories to reduce their problematic impact. We review here progress on reconsolidation updating studies, highlighting their translational exploitation and addressing recent challenges to the reconsolidation field.
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Affiliation(s)
- Jonathan L C Lee
- School of Psychology, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
| | - Karim Nader
- Department of Psychology, McGill University, Department of Psychology,1205 Dr Penfield Avenue, Montreal, QC H3A 1B1, Canada.
| | - Daniela Schiller
- Departments of Psychiatry and Neuroscience, Icahn School of Medicine at Mount Sinai and Friedman Brain Institute, New York, NY 10029, USA.
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Schroyens N, Beckers T, Kindt M. In Search for Boundary Conditions of Reconsolidation: A Failure of Fear Memory Interference. Front Behav Neurosci 2017; 11:65. [PMID: 28469565 PMCID: PMC5395559 DOI: 10.3389/fnbeh.2017.00065] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 03/29/2017] [Indexed: 11/24/2022] Open
Abstract
The presentation of a fear memory cue can result in mere memory retrieval, destabilization of the reactivated memory trace, or the formation of an extinction memory. The interaction between the degree of novelty during reactivation and previous learning conditions is thought to determine the outcome of a reactivation session. This study aimed to evaluate whether contextual novelty can prevent cue-induced destabilization and disruption of a fear memory acquired by non-asymptotic learning. To this end, fear memory was reactivated in a novel context or in the original context of learning, and fear memory reactivation was followed by the administration of propranolol, an amnestic drug. Remarkably, fear memory was not impaired by post-reactivation propranolol administration or extinction training under the usual conditions used in our lab, irrespective of the reactivation context. These unexpected findings are discussed in the light of our current experimental parameters and alleged boundary conditions on memory destabilization.
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Affiliation(s)
- Natalie Schroyens
- Department of Psychology, KU LeuvenLeuven, Belgium.,Department of Clinical Psychology, University of AmsterdamAmsterdam, Netherlands
| | - Tom Beckers
- Department of Psychology, KU LeuvenLeuven, Belgium.,Department of Clinical Psychology, University of AmsterdamAmsterdam, Netherlands
| | - Merel Kindt
- Department of Clinical Psychology, University of AmsterdamAmsterdam, Netherlands
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Sierra RO, Pedraza LK, Zanona QK, Santana F, Boos FZ, Crestani AP, Haubrich J, de Oliveira Alvares L, Calcagnotto ME, Quillfeldt JA. Reconsolidation-induced rescue of a remote fear memory blocked by an early cortical inhibition: Involvement of the anterior cingulate cortex and the mediation by the thalamic nucleus reuniens. Hippocampus 2017; 27:596-607. [DOI: 10.1002/hipo.22715] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/03/2017] [Indexed: 01/18/2023]
Affiliation(s)
- Rodrigo O. Sierra
- Psychobiology and Neurocomputing Lab; Biophysics Department, IB, CEP 91.501-970, Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
- Graduate Program in Neuroscience; ICBS, CEP 90.046-900, Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
| | - Lizeth K. Pedraza
- Graduate Program in Neuroscience; ICBS, CEP 90.046-900, Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
- Neurobiology of Memory Lab; Biophysics Department, IB, CEP 91.501-970, Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
| | - Querusche K. Zanona
- Psychobiology and Neurocomputing Lab; Biophysics Department, IB, CEP 91.501-970, Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
- Graduate Program in Neuroscience; ICBS, CEP 90.046-900, Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
| | - Fabiana Santana
- Psychobiology and Neurocomputing Lab; Biophysics Department, IB, CEP 91.501-970, Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
- Graduate Program in Neuroscience; ICBS, CEP 90.046-900, Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
| | - Flávia Z. Boos
- Psychobiology and Neurocomputing Lab; Biophysics Department, IB, CEP 91.501-970, Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
- Graduate Program in Neuroscience; ICBS, CEP 90.046-900, Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
| | - Ana P. Crestani
- Psychobiology and Neurocomputing Lab; Biophysics Department, IB, CEP 91.501-970, Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
- Graduate Program in Neuroscience; ICBS, CEP 90.046-900, Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
| | - Josué Haubrich
- Psychobiology and Neurocomputing Lab; Biophysics Department, IB, CEP 91.501-970, Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
- Graduate Program in Neuroscience; ICBS, CEP 90.046-900, Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
| | - Lucas de Oliveira Alvares
- Graduate Program in Neuroscience; ICBS, CEP 90.046-900, Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
- Neurobiology of Memory Lab; Biophysics Department, IB, CEP 91.501-970, Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
| | - Maria Elisa Calcagnotto
- Graduate Program in Neuroscience; ICBS, CEP 90.046-900, Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
- Neurophysiology and Neurochemistry of Neuronal Excitability and Synaptic Plasticity Lab; Biochemistry Department, ICBS, CEP 90.030-003, Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
| | - Jorge A. Quillfeldt
- Psychobiology and Neurocomputing Lab; Biophysics Department, IB, CEP 91.501-970, Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
- Graduate Program in Neuroscience; ICBS, CEP 90.046-900, Universidade Federal do Rio Grande do Sul; Porto Alegre Brazil
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57
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Endocannabinoid signaling and memory dynamics: A synaptic perspective. Neurobiol Learn Mem 2017; 138:62-77. [DOI: 10.1016/j.nlm.2016.07.031] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 07/21/2016] [Accepted: 07/29/2016] [Indexed: 01/26/2023]
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58
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Chang SD, Liang KC. The hippocampus integrates context and shock into a configural memory in contextual fear conditioning. Hippocampus 2016; 27:145-155. [DOI: 10.1002/hipo.22679] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/31/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Shih-Dar Chang
- Department of Psychology; National Taiwan University; Taipei 10617 Taiwan
| | - K. C. Liang
- Department of Psychology; National Taiwan University; Taipei 10617 Taiwan
- Graduate Institute for Brain and Mind Science, National Taiwan University; Taipei 10617 Taiwan
- Neurobiology and Cognitive Science Center, National Taiwan University; Taipei 10617 Taiwan
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59
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Stress-induced resistance to the fear memory labilization/reconsolidation process. Involvement of the basolateral amygdala complex. Neuropharmacology 2016; 109:349-356. [DOI: 10.1016/j.neuropharm.2016.06.033] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 06/23/2016] [Accepted: 06/30/2016] [Indexed: 02/07/2023]
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60
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Parsons RG, Walker DL, Davis M. Mechanisms underlying long-term fear memory formation from a metaplastic neuronal state. Neurobiol Learn Mem 2016; 136:47-53. [PMID: 27660077 DOI: 10.1016/j.nlm.2016.09.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 08/15/2016] [Accepted: 09/17/2016] [Indexed: 12/16/2022]
Abstract
We previously showed that a single weak fear conditioning trial, that does not produce a long-term fear memory (LTM), appeared to prime memory formation such that when a second trial followed within a circumscribed time window a robust and long-lasting fear memory was formed. We also showed that this priming effect could be blocked if we interfered with protein kinase A (PKA) signaling in the amygdala during the first conditioning trial. The goals of the current study were to determine if LTM formation after the second trial depends on PKA signaling in the amygdala and to characterize the underlying memory processes engaged during the second trial that allows for LTM formation. Our interpretation of the original findings is that the second conditioning trial triggers LTM from a metaplastic state that is engaged by the first conditioning trial. However, it is also possible that the second conditioning trial acts as a reminder of the first and engages a reconsolidation-like process. Several experiments were conducted to distinguish between these two possibilities. We show that interfering with PKA signaling during the second conditioning trial disrupts memory formation. However, if a third trial follows the second or if the second trial was presented without shock, the PKA inhibitor was no longer effective. Our findings demonstrate that the induction of fear memory from a metaplastic state involves new learning that is distinct from retrieval-dependent updating of memories.
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Affiliation(s)
- Ryan G Parsons
- Emory University, Department of Psychiatry and Behavioral Sciences, United States; Stony Brook University, Department of Psychology and Neurosciences Institute, United States.
| | - David L Walker
- Emory University, Department of Psychiatry and Behavioral Sciences, United States
| | - Michael Davis
- Emory University, Department of Psychiatry and Behavioral Sciences, United States
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61
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Ferrer Monti RI, Giachero M, Alfei JM, Bueno AM, Cuadra G, Molina VA. An appetitive experience after fear memory destabilization attenuates fear retention: involvement GluN2B-NMDA receptors in the Basolateral Amygdala Complex. Learn Mem 2016; 23:465-78. [PMID: 27531837 PMCID: PMC4986855 DOI: 10.1101/lm.042564.116] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 05/31/2016] [Indexed: 12/15/2022]
Abstract
It is known that a consolidated memory can return to a labile state and become transiently malleable following reactivation. This instability is followed by a restabilization phase termed reconsolidation. In this work, we explored whether an unrelated appetitive experience (voluntary consumption of diluted sucrose) can affect a contextual fear memory in rats during the reactivation-induced destabilization phase. Our findings show that exposure to an appetitive experience following reactivation can diminish fear retention. This effect persisted after 1 wk. Importantly, it was achieved only under conditions that induced fear memory destabilization. This result could not be explained as a potentiated extinction, because sucrose was unable to promote extinction. Since GluN2B-containing NMDA receptors in the basolateral amygdala complex (BLA) have been implicated in triggering fear memory destabilization, we decided to block pharmacologically these receptors to explore the neurobiological bases of the observed effect. Intra-BLA infusion with ifenprodil, a GluN2B-NMDA antagonist, prevented the fear reduction caused by the appetitive experience. In sum, these results suggest that the expression of a fear memory can be dampened by an unrelated appetitive experience, as long as memory destabilization is achieved during reactivation. Possible mechanisms behind this effect and its clinical implications are discussed.
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Affiliation(s)
- Roque I Ferrer Monti
- Laboratorio de Psicología Experimental, Facultad de Psicología, Universidad Nacional de Córdoba, Enfermera Gordillo y Enrique Barros, Ciudad Universitaria, 5000 Córdoba, Argentina
| | - Marcelo Giachero
- IFEC-CONICET, Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5000 Córdoba, Argentina
| | - Joaquín M Alfei
- Laboratorio de Psicología Experimental, Facultad de Psicología, Universidad Nacional de Córdoba, Enfermera Gordillo y Enrique Barros, Ciudad Universitaria, 5000 Córdoba, Argentina Department of Psychology, University of Leuven, 3000 Leuven, Belgium
| | - Adrián M Bueno
- Laboratorio de Psicología Experimental, Facultad de Psicología, Universidad Nacional de Córdoba, Enfermera Gordillo y Enrique Barros, Ciudad Universitaria, 5000 Córdoba, Argentina
| | - Gabriel Cuadra
- IFEC-CONICET, Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5000 Córdoba, Argentina
| | - Victor A Molina
- IFEC-CONICET, Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5000 Córdoba, Argentina
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62
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The fate of memory: Reconsolidation and the case of Prediction Error. Neurosci Biobehav Rev 2016; 68:423-441. [DOI: 10.1016/j.neubiorev.2016.06.004] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 05/07/2016] [Accepted: 06/06/2016] [Indexed: 11/22/2022]
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63
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Sachser RM, Haubrich J, Lunardi PS, de Oliveira Alvares L. Forgetting of what was once learned: Exploring the role of postsynaptic ionotropic glutamate receptors on memory formation, maintenance, and decay. Neuropharmacology 2016; 112:94-103. [PMID: 27425202 DOI: 10.1016/j.neuropharm.2016.07.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 07/12/2016] [Accepted: 07/13/2016] [Indexed: 12/26/2022]
Abstract
Over the past years, extensive research in experimental cognitive neuroscience has provided a comprehensive understanding about the role of ionotropic glutamate receptor (IGluR)-dependent signaling underpinning postsynaptic plasticity induced by long-term potentiation (LTP), the leading cellular basis of long-term memory (LTM). However, despite the fact that iGluR-mediated postsynaptic plasticity regulates the formation and persistence of LTP and LTM, here we discuss the state-of-the-art regarding the mechanisms underpinning both LTP and LTM decay. First, we review the crucial roles that iGluRs play on memory encoding and stabilization. Second, we discuss the latest findings in forgetting considering hippocampal GluA2-AMPAR trafficking at postsynaptic sites as well as dendritic spine remodeling possibly involved in LTP decay. Third, on the role of retrieving consolidated LTMs, we discuss the mechanisms involved in memory destabilization that occurs followed reactivation that share striking similarities with the neurobiological basis of forgetting. Fourth, since different AMPAR subunits as well as postsynaptic scaffolding proteins undergo ubiquitination, the ubiquitin-proteasome system (UPS) is discussed in light of memory decay. In conclusion, we provide an integrated overview revealing some of the mechanisms determining memory forgetting that are mediated by iGluRs. This article is part of the Special Issue entitled 'Ionotropic glutamate receptors'.
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Affiliation(s)
- Ricardo Marcelo Sachser
- Neurobiology of Memory Lab, Biophysics Department, Bioscience Institute, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil; Graduate Program in Neuroscience, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Josué Haubrich
- Psychobiology and Neurocomputation Lab, Biophysics Department, Bioscience Institute, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil; Graduate Program in Neuroscience, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Paula Santana Lunardi
- Neurobiology of Memory Lab, Biophysics Department, Bioscience Institute, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil; Graduate Program in Neuroscience, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Lucas de Oliveira Alvares
- Neurobiology of Memory Lab, Biophysics Department, Bioscience Institute, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil; Graduate Program in Neuroscience, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
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64
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Scholz B, Doidge AN, Barnes P, Hall J, Wilkinson LS, Thomas KL. The Regulation of Cytokine Networks in Hippocampal CA1 Differentiates Extinction from Those Required for the Maintenance of Contextual Fear Memory after Recall. PLoS One 2016; 11:e0153102. [PMID: 27224427 PMCID: PMC4880201 DOI: 10.1371/journal.pone.0153102] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 03/23/2016] [Indexed: 12/17/2022] Open
Abstract
We investigated the distinctiveness of gene regulatory networks in CA1 associated with the extinction of contextual fear memory (CFM) after recall using Affymetrix GeneChip Rat Genome 230 2.0 Arrays. These data were compared to previously published retrieval and reconsolidation-attributed, and consolidation datasets. A stringent dual normalization and pareto-scaled orthogonal partial least-square discriminant multivariate analysis together with a jack-knifing-based cross-validation approach was used on all datasets to reduce false positives. Consolidation, retrieval and extinction were correlated with distinct patterns of gene expression 2 hours later. Extinction-related gene expression was most distinct from the profile accompanying consolidation. A highly specific feature was the discrete regulation of neuroimmunological gene expression associated with retrieval and extinction. Immunity-associated genes of the tyrosine kinase receptor TGFβ and PDGF, and TNF families' characterized extinction. Cytokines and proinflammatory interleukins of the IL-1 and IL-6 families were enriched with the no-extinction retrieval condition. We used comparative genomics to predict transcription factor binding sites in proximal promoter regions of the retrieval-regulated genes. Retrieval that does not lead to extinction was associated with NF-κB-mediated gene expression. We confirmed differential NF-κBp65 expression, and activity in all of a representative sample of our candidate genes in the no-extinction condition. The differential regulation of cytokine networks after the acquisition and retrieval of CFM identifies the important contribution that neuroimmune signalling plays in normal hippocampal function. Further, targeting cytokine signalling upon retrieval offers a therapeutic strategy to promote extinction mechanisms in human disorders characterised by dysregulation of associative memory.
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Affiliation(s)
- Birger Scholz
- Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Amie N. Doidge
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Philip Barnes
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Jeremy Hall
- Neuroscience & Mental Health Research Institute, Cardiff University, Cardiff, United Kingdom
| | - Lawrence S. Wilkinson
- Neuroscience & Mental Health Research Institute, Cardiff University, Cardiff, United Kingdom
- Schools of Psychology and Medicine, Behavioral Genetics Group, Cardiff University, Cardiff, United Kingdom
- MRC Centre for Neuropsychiatric Genetics and Genomics and Institute of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Kerrie L. Thomas
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
- Neuroscience & Mental Health Research Institute, Cardiff University, Cardiff, United Kingdom
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65
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CaMKII regulates proteasome phosphorylation and activity and promotes memory destabilization following retrieval. Neurobiol Learn Mem 2016; 128:103-9. [PMID: 26779588 DOI: 10.1016/j.nlm.2016.01.001] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 12/30/2015] [Accepted: 01/05/2016] [Indexed: 01/04/2023]
Abstract
Numerous studies have suggested that memories "destabilize" and require de novo protein synthesis in order to reconsolidate following retrieval, but very little is known about how this destabilization process is regulated. Recently, ubiquitin-proteasome mediated protein degradation has been identified as a critical regulator of memory trace destabilization following retrieval, though the specific mechanisms controlling retrieval-induced changes in ubiquitin-proteasome activity remain equivocal. Here, we found that proteasome activity is increased in the amygdala in a CaMKII-dependent manner following the retrieval of a contextual fear memory. We show that in vitro inhibition of CaMKII reversed retrieval-induced increases in proteasome activity. Additionally, in vivo pharmacological blockade of CaMKII abolished increases in proteolytic activity and activity related regulatory phosphorylation in the amygdala following retrieval, suggesting that CaMKII was "upstream" of protein degradation during the memory reconsolidation process. Consistent with this, while inhibiting CaMKII in the amygdala did not impair memory following retrieval, it completely attenuated the memory impairments that resulted from post-retrieval protein synthesis blockade. Collectively, these results suggest that CaMKII controls the initiation of the memory reconsolidation process through regulation of the proteasome.
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66
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Chakraborty T, Asok A, Stanton ME, Rosen JB. Variants of contextual fear conditioning induce differential patterns of Egr-1 activity within the young adult prefrontal cortex. Behav Brain Res 2016; 302:122-30. [PMID: 26778782 DOI: 10.1016/j.bbr.2016.01.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 12/24/2015] [Accepted: 01/05/2016] [Indexed: 01/17/2023]
Abstract
Contextual fear conditioning is a form of associative learning where animals must experience a context before they can associate it with an aversive stimulus. Single-trial contextual fear conditioning (sCFC) and the context preexposure facilitation effect (CPFE) are two variants of CFC where learning about the context is temporally contiguous (sCFC) with or separated (CPFE) from receiving a footshock in that context. Neural activity within CA1 of the dorsal hippocampus (CA1), amygdala (LA), and prefrontal cortex (PFC) may play a critical role when animals learn to associate a context with a footshock (i.e., training). Previous studies from our lab have found that early-growth-response gene 1 (Egr-1), an immediate early gene, exhibits unique patterns of activity within regions of the PFC following training in sCFC and the CPFE of juvenile rats. In the present study, we extended our studies by examining Egr-1 expression in young adult rats to determine (1) if our previous work reflected changes unique to development or extend into adulthood and (2) to contrast expression profiles between sCFC and the CPFE. Rats that learned context fear with sCFC showed increased Egr-1 in the anterior cingulate, orbitofrontal and infralimbic cortices relative to non-associative controls following training, but expression in prelimbic cortex did not differ between fear conditioned and non-associative controls. In contrast, rats trained in the CPFE also showed increased Egr-1 in all the prefrontal cortex regions, including prelimbic cortex. These findings replicate our previous findings in juveniles and suggest that Egr-1 in specific PFC subregions may be uniquely involved in learning context-fear in the CPFE compared to sCFC.
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Affiliation(s)
- T Chakraborty
- University of Delaware, Department of Psychological and Brain Sciences, Newark, DE 19716, United States
| | - A Asok
- University of Delaware, Department of Psychological and Brain Sciences, Newark, DE 19716, United States
| | - M E Stanton
- University of Delaware, Department of Psychological and Brain Sciences, Newark, DE 19716, United States
| | - J B Rosen
- University of Delaware, Department of Psychological and Brain Sciences, Newark, DE 19716, United States.
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67
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Updating stored memory requires adult hippocampal neurogenesis. Sci Rep 2015; 5:13993. [PMID: 26358557 PMCID: PMC4566137 DOI: 10.1038/srep13993] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Accepted: 08/13/2015] [Indexed: 11/23/2022] Open
Abstract
Adult hippocampal neurogenesis appears to influence hippocampal functions, such as memory formation for example. While adult hippocampal neurogenesis is known to be involved in hippocampal-dependent learning and consolidation processes, the role of such immature neurons in memory reconsolidation, a process involved in the modification of stored memories, remains unclear. Here, using a novel fast X-ray ablation protocol to deplete neurogenic cells, we have found that adult hippocampal neurogenesis is required to update object recognition stored memory more than to reinforce it. Indeed, we show that immature neurons were selectively recruited to hippocampal circuits during the updating of stored information. Thus, our data demonstrate a new role for neurogenesis in cognitive processes, adult hippocampal neurogenesis being required for the updating of stored OR memories. These findings suggest that manipulating adult neurogenesis may have a therapeutic application in conditions associated with traumatic stored memory, for example.
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68
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Crestani AP, Zacouteguy Boos F, Haubrich J, Ordoñez Sierra R, Santana F, Molina JMD, Cassini LDF, Alvares LDO, Quillfeldt JA. Memory reconsolidation may be disrupted by a distractor stimulus presented during reactivation. Sci Rep 2015; 5:13633. [PMID: 26328547 PMCID: PMC4556962 DOI: 10.1038/srep13633] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 08/03/2015] [Indexed: 12/27/2022] Open
Abstract
Memories can be destabilized by the reexposure to the training context, and may reconsolidate into a modified engram. Reconsolidation relies on some particular molecular mechanisms involving LVGCCs and GluN2B-containing NMDARs. In this study we investigate the interference caused by the presence of a distractor - a brief, unanticipated stimulus that impair a fear memory expression - during the reactivation session, and tested the hypothesis that this disruptive effect relies on a reconsolidation process. Rats previously trained in the contextual fear conditioning (CFC) were reactivated in the presence or absence of a distractor stimulus. In the test, groups reactivated in the original context with distractor displayed a reduction of the freezing response lasting up to 20 days. To check for the involvement of destabilization / reconsolidation mechanisms, we studied the effect of systemic nimodipine (a L-VGCC blocker) or intra-CA1 ifenprodil (a selective GluN2B/NMDAR antagonist) infused right before the reactivation session. Both treatments were able to prevent the disruptive effect of distraction. Ifenprodil results also bolstered the case for hippocampus as the putative brain structure hosting this phenomenon. Our results provide some evidence in support of a behavioral, non-invasive procedure that was able to disrupt an aversive memory in a long-lasting way.
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Affiliation(s)
- Ana Paula Crestani
- Psychobiology and Neurocomputation Lab, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.,Neurosciences Graduate Program, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Flávia Zacouteguy Boos
- Psychobiology and Neurocomputation Lab, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.,Neurosciences Graduate Program, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Josué Haubrich
- Psychobiology and Neurocomputation Lab, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.,Neurosciences Graduate Program, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Rodrigo Ordoñez Sierra
- Psychobiology and Neurocomputation Lab, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.,Neurosciences Graduate Program, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Fabiana Santana
- Psychobiology and Neurocomputation Lab, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.,Neurosciences Graduate Program, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Johanna Marcela Duran Molina
- Psychobiology and Neurocomputation Lab, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.,Neurosciences Graduate Program, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Lindsey de Freitas Cassini
- Psychobiology and Neurocomputation Lab, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.,Neurosciences Graduate Program, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Lucas de Oliveira Alvares
- Psychobiology and Neurocomputation Lab, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.,Neurosciences Graduate Program, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Jorge Alberto Quillfeldt
- Psychobiology and Neurocomputation Lab, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.,Neurosciences Graduate Program, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
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69
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Gisquet-Verrier P, Lynch JF, Cutolo P, Toledano D, Ulmen A, Jasnow AM, Riccio DC. Integration of New Information with Active Memory Accounts for Retrograde Amnesia: A Challenge to the Consolidation/Reconsolidation Hypothesis? J Neurosci 2015; 35:11623-33. [PMID: 26290239 PMCID: PMC6605236 DOI: 10.1523/jneurosci.1386-15.2015] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 06/25/2015] [Accepted: 07/01/2015] [Indexed: 12/31/2022] Open
Abstract
Active (new and reactivated) memories are considered to be labile and sensitive to treatments disrupting the time-dependent consolidation/reconsolidation processes required for their stabilization. Active memories also allow the integration of new information for updating memories. Here, we investigate the possibility that, when active, the internal state provided by amnesic treatments is represented and integrated within the initial memory and that amnesia results from the absence of this state at testing. We showed in rats that the amnesia resulting from systemic, intracerebroventricular and intrahippocampal injections of the protein synthesis inhibitor cycloheximide, administered after inhibitory avoidance training or reactivation, can be reversed by a reminder, including re-administration of the same drug. Similar results were obtained with lithium chloride (LiCl), which does not affect protein synthesis, when delivered systemically after training or reactivation. However, LiCl can induce memory given that a conditioned taste aversion was obtained for a novel taste, presented just before conditioning or reactivation. These results indicate that memories can be established and maintained without de novo protein synthesis and that experimental amnesia may not result from a disruption of memory consolidation/reconsolidation. The findings more likely support the integration hypothesis: posttraining/postreactivation treatments induce an internal state, which becomes encoded with the memory, and should be present at the time of testing to ensure a successful retrieval. This integration concept includes most of the previous explanations of memory recovery after retrograde amnesia and critically challenges the traditional memory consolidation/reconsolidation hypothesis, providing a more dynamic and flexible view of memory. SIGNIFICANCE STATEMENT This study provides evidence challenging the traditional consolidation/reconsolidation hypotheses that have dominated the literature over the past 50 years. Based on amnesia studies, that hypothesis states that active (i.e., new and reactivated) memories are similarly labile and (re)established in a time-dependent manner within the brain through processes that require de novo protein synthesis. Our data show that new/reactivated memories can be formed without protein synthesis and that amnesia can be induced by drugs that do not affect protein synthesis. We propose that amnesia results from memory integration of the internal state produced by the drug that is subsequently necessary for retrieval of the memory. This interpretation gives a dynamic view of memory, rapidly stored and easily updated when active.
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Affiliation(s)
- Pascale Gisquet-Verrier
- CNRS, University Paris-Sud, Neuroscience Paris-Saclay Institute (NeuroPSI), UMR 9197, F-91405 Orsay, France, and
| | - Joseph F Lynch
- Department of Psychological Sciences, Kent State University, Kent, Ohio 44242
| | - Pasquale Cutolo
- CNRS, University Paris-Sud, Neuroscience Paris-Saclay Institute (NeuroPSI), UMR 9197, F-91405 Orsay, France, and
| | - Daniel Toledano
- CNRS, University Paris-Sud, Neuroscience Paris-Saclay Institute (NeuroPSI), UMR 9197, F-91405 Orsay, France, and
| | - Adam Ulmen
- Department of Psychological Sciences, Kent State University, Kent, Ohio 44242
| | - Aaron M Jasnow
- Department of Psychological Sciences, Kent State University, Kent, Ohio 44242
| | - David C Riccio
- Department of Psychological Sciences, Kent State University, Kent, Ohio 44242
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70
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Furini CRG, Myskiw JDC, Schmidt BE, Zinn CG, Peixoto PB, Pereira LD, Izquierdo I. The relationship between protein synthesis and protein degradation in object recognition memory. Behav Brain Res 2015. [PMID: 26200717 DOI: 10.1016/j.bbr.2015.07.038] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
For decades there has been a consensus that de novo protein synthesis is necessary for long-term memory. A second round of protein synthesis has been described for both extinction and reconsolidation following an unreinforced test session. Recently, it was shown that consolidation and reconsolidation depend not only on protein synthesis but also on protein degradation by the ubiquitin-proteasome system (UPS), a major mechanism responsible for protein turnover. However, the involvement of UPS on consolidation and reconsolidation of object recognition memory remains unknown. Here we investigate in the CA1 region of the dorsal hippocampus the involvement of UPS-mediated protein degradation in consolidation and reconsolidation of object recognition memory. Animals with infusion cannulae stereotaxically implanted in the CA1 region of the dorsal hippocampus, were exposed to an object recognition task. The UPS inhibitor β-Lactacystin did not affect the consolidation and the reconsolidation of object recognition memory at doses known to affect other forms of memory (inhibitory avoidance, spatial learning in a water maze) while the protein synthesis inhibitor anisomycin impaired the consolidation and the reconsolidation of the object recognition memory. However, β-Lactacystin was able to reverse the impairment caused by anisomycin on the reconsolidation process in the CA1 region of the hippocampus. Therefore, it is possible to postulate a direct link between protein degradation and protein synthesis during the reconsolidation of the object recognition memory.
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Affiliation(s)
- Cristiane R G Furini
- National Institute of Translational Neuroscience (INNT), National Research Council of Brazil, and Memory Center, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2nd Floor, 90610-000 Porto Alegre, RS, Brazil
| | - Jociane de C Myskiw
- National Institute of Translational Neuroscience (INNT), National Research Council of Brazil, and Memory Center, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2nd Floor, 90610-000 Porto Alegre, RS, Brazil
| | - Bianca E Schmidt
- National Institute of Translational Neuroscience (INNT), National Research Council of Brazil, and Memory Center, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2nd Floor, 90610-000 Porto Alegre, RS, Brazil
| | - Carolina G Zinn
- National Institute of Translational Neuroscience (INNT), National Research Council of Brazil, and Memory Center, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2nd Floor, 90610-000 Porto Alegre, RS, Brazil
| | - Patricia B Peixoto
- National Institute of Translational Neuroscience (INNT), National Research Council of Brazil, and Memory Center, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2nd Floor, 90610-000 Porto Alegre, RS, Brazil
| | - Luiza D Pereira
- National Institute of Translational Neuroscience (INNT), National Research Council of Brazil, and Memory Center, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2nd Floor, 90610-000 Porto Alegre, RS, Brazil
| | - Ivan Izquierdo
- National Institute of Translational Neuroscience (INNT), National Research Council of Brazil, and Memory Center, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 2nd Floor, 90610-000 Porto Alegre, RS, Brazil.
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71
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Reconsolidation and the regulation of plasticity: moving beyond memory. Trends Neurosci 2015; 38:336-44. [PMID: 25987442 DOI: 10.1016/j.tins.2015.04.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 04/20/2015] [Accepted: 04/21/2015] [Indexed: 01/31/2023]
Abstract
Memory reconsolidation is a protein synthesis-dependent process that preserves, in some form, memories that have been destabilized through recall. Reconsolidation is a nearly universal phenomenon, occurring in a diverse array of species and learning tasks. The function of reconsolidation remains unclear but it has been proposed as a mechanism for updating or strengthening memories. Observations of an analog of reconsolidation in vitro and in sensory systems indicate that reconsolidation is unlikely to be a learning-specific phenomenon and may serve a broader function. We propose that reconsolidation arises from the activity-dependent induction of two coincident but opposing processes: the depotentiation and repotentiation of strengthened synapses. These processes suggest that reconsolidation reflects a fundamental mechanism that regulates and preserves synaptic strength.
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72
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Sorg BA, Todd RP, Slaker M, Churchill L. Anisomycin in the medial prefrontal cortex reduces reconsolidation of cocaine-associated memories in the rat self-administration model. Neuropharmacology 2015; 92:25-33. [PMID: 25576371 PMCID: PMC4346388 DOI: 10.1016/j.neuropharm.2014.12.029] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 12/12/2014] [Accepted: 12/22/2014] [Indexed: 12/19/2022]
Abstract
We tested the hypothesis that infusion of anisomycin into the medial prefrontal cortex (mPFC) disrupts the reconsolidation of a cocaine-associated memory in the rat cocaine self-administration model. Male Sprague-Dawley rats were trained to lever press for cocaine self-administration (0.5 mg/kg/infusion) along with a cue light presentation on an FR1 followed by an FR3 schedule of reinforcement for 2 h/day. Rats were then given extinction sessions or an equivalent forced abstinence period followed by a 5 min memory reactivation session during which time they received an ip cocaine injection (10 mg/kg, ip) and were allowed to press for contingent cue light presentation. Immediately after reactivation, they were administered an intra-mPFC infusion of vehicle or anisomycin. Two additional control groups received extinction and either no memory reactivation and intra-mPFC infusions as above or intra-mPFC infusions 6 h after memory reactivation. A fourth group received forced abstinence and intra-mPFC infusions immediately after memory reactivation. Combined cocaine + cue-induced reinstatement was given 2-3 days (early) and 8-12 days (late) later. Rats given anisomycin in the Extinction + Reactivation demonstrated decreased reinstatement, while anisomycin treatment did not alter behavior in any of the other three groups. These results suggest that extinction training may recruit the mPFC such that it renders the memory susceptible to disruption by anisomycin. These findings have implications for using extinction training prior to or in conjunction with other therapies, including reconsolidation disruption, to enhance prefrontal control over drug-seeking behavior.
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Affiliation(s)
- Barbara A Sorg
- Translational Addiction Research Center and Alcohol and Drug Abuse Research Program, Department of Integrative Physiology and Neuroscience, Washington State University, Vancouver, WA 98686, USA.
| | - Ryan P Todd
- Translational Addiction Research Center and Alcohol and Drug Abuse Research Program, Department of Integrative Physiology and Neuroscience, Washington State University, Vancouver, WA 98686, USA
| | - Megan Slaker
- Translational Addiction Research Center and Alcohol and Drug Abuse Research Program, Department of Integrative Physiology and Neuroscience, Washington State University, Vancouver, WA 98686, USA
| | - Lynn Churchill
- Translational Addiction Research Center and Alcohol and Drug Abuse Research Program, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA
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73
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Slaker M, Churchill L, Todd RP, Blacktop JM, Zuloaga DG, Raber J, Darling RA, Brown TE, Sorg BA. Removal of perineuronal nets in the medial prefrontal cortex impairs the acquisition and reconsolidation of a cocaine-induced conditioned place preference memory. J Neurosci 2015; 35:4190-202. [PMID: 25762666 PMCID: PMC4355195 DOI: 10.1523/jneurosci.3592-14.2015] [Citation(s) in RCA: 149] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 01/23/2015] [Accepted: 01/28/2015] [Indexed: 12/29/2022] Open
Abstract
Pyramidal neurons in the medial prefrontal cortex (mPFC) critically contribute to cocaine-seeking behavior in humans and rodents. Activity of these neurons is significantly modulated by GABAergic, parvalbumin-containing, fast-spiking interneurons, the majority of which are enveloped by specialized structures of extracellular matrix called perineuronal nets (PNNs), which are integral to the maintenance of many types of plasticity. Using a conditioned place preference (CPP) procedure, we found that removal of PNNs primarily from the prelimbic region of the mPFC of adult, male, Sprague Dawley rats impaired the acquisition and reconsolidation of a cocaine-induced CPP memory. This impairment was accompanied by a decrease in the number of c-Fos-positive cells surrounded by PNNs. Following removal of PNNs, the frequency of inhibitory currents in mPFC pyramidal neurons was decreased; but following cocaine-induced CPP, both frequency and amplitude of inhibitory currents were decreased. Our findings suggest that cocaine-induced plasticity is impaired by removal of prelimbic mPFC PNNs and that PNNs may be a therapeutic target for disruption of cocaine CPP memories.
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Affiliation(s)
- Megan Slaker
- Department of Integrative Physiology and Neuroscience, Washington State University, Vancouver, Washington 98686
| | - Lynn Churchill
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington 99164
| | - Ryan P Todd
- Department of Integrative Physiology and Neuroscience, Washington State University, Vancouver, Washington 98686
| | - Jordan M Blacktop
- Department of Integrative Physiology and Neuroscience, Washington State University, Vancouver, Washington 98686
| | - Damian G Zuloaga
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, Oregon 97239
| | - Jacob Raber
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, Oregon 97239, Departments of Neurology and Radiation Medicine, Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, Portland, Oregon 97239, and
| | - Rebecca A Darling
- School of Pharmacy and Department of Neuroscience, University of Wyoming, Laramie, Wyoming 82071
| | - Travis E Brown
- School of Pharmacy and Department of Neuroscience, University of Wyoming, Laramie, Wyoming 82071
| | - Barbara A Sorg
- Department of Integrative Physiology and Neuroscience, Washington State University, Vancouver, Washington 98686,
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74
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Exton-McGuinness MT, Lee JL, Reichelt AC. Updating memories—The role of prediction errors in memory reconsolidation. Behav Brain Res 2015; 278:375-84. [DOI: 10.1016/j.bbr.2014.10.011] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 10/08/2014] [Accepted: 10/10/2014] [Indexed: 10/24/2022]
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75
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Heath FC, Jurkus R, Bast T, Pezze MA, Lee JLC, Voigt JP, Stevenson CW. Dopamine D1-like receptor signalling in the hippocampus and amygdala modulates the acquisition of contextual fear conditioning. Psychopharmacology (Berl) 2015; 232:2619-29. [PMID: 25743759 PMCID: PMC4480849 DOI: 10.1007/s00213-015-3897-y] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 02/16/2015] [Indexed: 12/11/2022]
Abstract
RATIONALE Dopamine D1-like receptor signalling is involved in contextual fear conditioning, but the brain regions involved and its role in other contextual fear memory processes remain unclear. OBJECTIVES The objective of this study was to investigate (1) the effects of SCH 23390, a dopamine D1/D5 receptor antagonist, on contextual fear memory encoding, retrieval and reconsolidation, and (2) if the effects of SCH 23390 on conditioning involve the dorsal hippocampus (DH) and/or basolateral amygdala (BLA). METHODS Rats were used to examine the effects of systemically administering SCH 23390 on the acquisition, consolidation, retrieval and reconsolidation of contextual fear memory, and on locomotor activity and shock sensitivity. We also determined the effects of MK-801, an NMDA receptor antagonist, on contextual fear memory reconsolidation. The effects of infusing SCH 23390 locally into DH or BLA on contextual fear conditioning and locomotor activity were also examined. RESULTS Systemic administration of SCH 23390 impaired contextual fear conditioning but had no effects on fear memory consolidation, retrieval or reconsolidation. MK-801 was found to impair reconsolidation, suggesting that the behavioural parameters used allowed for the pharmacological disruption of memory reconsolidation. The effects of SCH 23390 on conditioning were unlikely the result of any lasting drug effects on locomotor activity at memory test or any acute drug effects on shock sensitivity during conditioning. SCH 23390 infused into either DH or BLA impaired contextual fear conditioning and decreased locomotor activity. CONCLUSIONS These findings suggest that dopamine D1-like receptor signalling in DH and BLA contributes to the acquisition of contextual fear memory.
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Affiliation(s)
- Florence C. Heath
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
| | - Regimantas Jurkus
- School of Mathematical Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
| | - Tobias Bast
- School of Psychology and Neuroscience, University of Nottingham, University Park, Nottingham, NG7 2RD UK
| | - Marie A. Pezze
- School of Psychology and Neuroscience, University of Nottingham, University Park, Nottingham, NG7 2RD UK
| | - Jonathan L. C. Lee
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
| | - J. Peter Voigt
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
| | - Carl W. Stevenson
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
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76
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Jarome TJ, Lubin FD. Epigenetic mechanisms of memory formation and reconsolidation. Neurobiol Learn Mem 2014; 115:116-27. [PMID: 25130533 PMCID: PMC4250295 DOI: 10.1016/j.nlm.2014.08.002] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 08/02/2014] [Accepted: 08/05/2014] [Indexed: 10/24/2022]
Abstract
Memory consolidation involves transcriptional control of genes in neurons to stabilize a newly formed memory. Following retrieval, a once consolidated memory destabilizes and again requires gene transcription changes in order to restabilize, a process referred to as reconsolidation. Understanding the molecular mechanisms of gene transcription during the consolidation and reconsolidation processes could provide crucial insights into normal memory formation and memory dysfunction associated with psychiatric disorders. In the past decade, modifications of epigenetic markers such as DNA methylation and posttranslational modifications of histone proteins have emerged as critical transcriptional regulators of gene expression during initial memory formation and after retrieval. In light of the rapidly growing literature in this exciting area of research, we here examine the most recent and latest evidence demonstrating how memory acquisition and retrieval trigger epigenetic changes during the consolidation and reconsolidation phases to impact behavior. In particular we focus on the reconsolidation process, where we discuss the already identified epigenetic regulators of gene transcription during memory reconsolidation, while exploring other potential epigenetic modifications that may also be involved, and expand on how these epigenetic modifications may be precisely and temporally controlled by important signaling cascades critical to the reconsolidation process. Finally, we explore the possibility that epigenetic mechanisms may serve to regulate a system or circuit level reconsolidation process and may be involved in retrieval-dependent memory updating. Hence, we propose that epigenetic mechanisms coordinate changes in neuronal gene transcription, not only during the initial memory consolidation phase, but are triggered by retrieval to regulate molecular and cellular processes during memory reconsolidation.
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Affiliation(s)
- Timothy J Jarome
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Farah D Lubin
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294, United States.
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77
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Kwapis JL, Wood MA. Epigenetic mechanisms in fear conditioning: implications for treating post-traumatic stress disorder. Trends Neurosci 2014; 37:706-20. [PMID: 25220045 DOI: 10.1016/j.tins.2014.08.005] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 08/15/2014] [Accepted: 08/18/2014] [Indexed: 12/15/2022]
Abstract
Post-traumatic stress disorder (PTSD) and other anxiety disorders stemming from dysregulated fear memory are problematic and costly. Understanding the molecular mechanisms that contribute to the formation and maintenance of these persistent fear associations is crucial to developing treatments for PTSD. Epigenetic mechanisms, which control gene expression to produce long-lasting changes in cellular function, may support the formation of fear memory underlying PTSD. We address here the role of epigenetic mechanisms in the formation, storage, updating, and extinction of fear memories. We also discuss methods of targeting these epigenetic mechanisms to reduce the initial formation of fear memory or to enhance its extinction. Epigenetic mechanisms may provide a novel target for pharmaceutical and other treatments to reduce aversive memory contributing to PTSD.
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Affiliation(s)
- Janine L Kwapis
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA 92697, USA
| | - Marcelo A Wood
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA 92697, USA.
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78
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Exton-McGuinness MTJ, Patton RC, Sacco LB, Lee JLC. Reconsolidation of a well-learned instrumental memory. ACTA ACUST UNITED AC 2014; 21:468-77. [PMID: 25135195 PMCID: PMC4138356 DOI: 10.1101/lm.035543.114] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Once consolidated, memories are dynamic entities that go through phases of instability in order to be updated with new information, via a process of reconsolidation. The phenomenon of reconsolidation has been demonstrated in a wide variety of experimental paradigms. However, the memories underpinning instrumental behaviors are currently not believed to reconsolidate. We show that well-learned lever pressing in rats does undergo reconsolidation, which can be disrupted by systemic administration of the noncompetitive N-methyl-D-aspartate receptor (NMDAR) antagonist (+)-5-methyl-10,11-dihydro-SH-dibenzo[a,d]cyclohepten-5,10-imine maleate (MK-801) when administered prior to a switch to a variable, but not fixed, ratio schedule. Disruption of reconsolidation resulted in a reduction in long-term lever pressing performance and diminished the sensitivity of behavior to contingency change. Further investigation demonstrated that expression of the reconsolidation impairment was not affected by outcome value, implying a deficit in a stimulus–response (S–R) process. The ability to disrupt the performance of well-learned instrumental behaviors is potentially of great importance in the development of reconsolidation-based clinical treatments for conditions that involve compulsive seeking behaviors.
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Affiliation(s)
| | - Rosemary C Patton
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Lawrence B Sacco
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Jonathan L C Lee
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
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79
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Schreiber WB, Asok A, Jablonski SA, Rosen JB, Stanton ME. Egr-1 mRNA expression patterns in the prefrontal cortex, hippocampus, and amygdala during variants of contextual fear conditioning in adolescent rats. Brain Res 2014; 1576:63-72. [PMID: 24976583 PMCID: PMC4138218 DOI: 10.1016/j.brainres.2014.06.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 06/03/2014] [Accepted: 06/05/2014] [Indexed: 10/25/2022]
Abstract
We report activation of the immediate-early gene Egr-1 in the lateral amygdala (LA), hippocampus (CA1), and medial prefrontal cortex (mPFC) 30-min following the training phase in the context pre-exposure facilitation effect (CPFE) and standard context fear conditioning (180 s context exposure→shock). On day one of the CPFE paradigm, postnatal day (PD) 31 rats (±1) were pre-exposed to Context A (Pre) or Context B (Alt-Pre) for 5 min followed by five additional 1-min exposures. A day later, Pre and Alt-Pre rats received a 2-s, 1.5 mA footshock immediately upon placement in Context A. Animals included in in situ hybridization were then sacrificed 30 (±3) min later. On day three, the behaviorally-tested Pre rats showed significantly more fear-conditioned freezing in Context A than Alt-Pre rats. Standard context fear conditioning groups showed much greater freezing than the Pre group, as well as no shock and immediate-shock controls. Thirty minutes after immediate shock training, Pre rats showed increased Egr-1 mRNA in the prelimbic mPFC relative to Alt-Pre rats. Standard context conditioning selectively increased Egr-1 in CA1. In the LA and mPFC, Egr-1 increased to a similar extent in no shock, immediate shock, and standard context conditioning relative to homecage controls. The present study demonstrates that Egr-1 mRNA expression has a complex relationship to fear learning in different brain regions and variants of context conditioning.
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Affiliation(s)
- W B Schreiber
- Department of Psychological & Brain Sciences, University of Delaware, Newark, DE 19716, USA
| | - A Asok
- Department of Psychological & Brain Sciences, University of Delaware, Newark, DE 19716, USA
| | - S A Jablonski
- Department of Psychological & Brain Sciences, University of Delaware, Newark, DE 19716, USA
| | - J B Rosen
- Department of Psychological & Brain Sciences, University of Delaware, Newark, DE 19716, USA
| | - M E Stanton
- Department of Psychological & Brain Sciences, University of Delaware, Newark, DE 19716, USA.
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80
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Jarome TJ, Helmstetter FJ. Protein degradation and protein synthesis in long-term memory formation. Front Mol Neurosci 2014; 7:61. [PMID: 25018696 PMCID: PMC4072070 DOI: 10.3389/fnmol.2014.00061] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 06/09/2014] [Indexed: 11/19/2022] Open
Abstract
Long-term memory (LTM) formation requires transient changes in the activity of intracellular signaling cascades that are thought to regulate new gene transcription and de novo protein synthesis in the brain. Consistent with this, protein synthesis inhibitors impair LTM for a variety of behavioral tasks when infused into the brain around the time of training or following memory retrieval, suggesting that protein synthesis is a critical step in LTM storage in the brain. However, evidence suggests that protein degradation mediated by the ubiquitin-proteasome system (UPS) may also be a critical regulator of LTM formation and stability following retrieval. This requirement for increased protein degradation has been shown in the same brain regions in which protein synthesis is required for LTM storage. Additionally, increases in the phosphorylation of proteins involved in translational control parallel increases in protein polyubiquitination and the increased demand for protein degradation is regulated by intracellular signaling molecules thought to regulate protein synthesis during LTM formation. In some cases inhibiting proteasome activity can rescue memory impairments that result from pharmacological blockade of protein synthesis, suggesting that protein degradation may control the requirement for protein synthesis during the memory storage process. Results such as these suggest that protein degradation and synthesis are both critical for LTM formation and may interact to properly “consolidate” and store memories in the brain. Here, we review the evidence implicating protein synthesis and degradation in LTM storage and highlight the areas of overlap between these two opposing processes. We also discuss evidence suggesting these two processes may interact to properly form and store memories. LTM storage likely requires a coordinated regulation between protein degradation and synthesis at multiple sites in the mammalian brain.
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Affiliation(s)
- Timothy J Jarome
- Department of Neurobiology, University of Alabama at Birmingham Birmingham, AL, USA ; Department of Psychology, University of Wisconsin-Milwaukee Milwaukee, WI, USA
| | - Fred J Helmstetter
- Department of Psychology, University of Wisconsin-Milwaukee Milwaukee, WI, USA
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81
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Gebicke-Haerter PJ. Engram formation in psychiatric disorders. Front Neurosci 2014; 8:118. [PMID: 24904262 PMCID: PMC4036307 DOI: 10.3389/fnins.2014.00118] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 05/02/2014] [Indexed: 01/17/2023] Open
Abstract
Environmental factors substantially influence beginning and progression of mental illness, reinforcing or reducing the consequences of genetic vulnerability. Often initiated by early traumatic events, “engrams” or memories are formed that may give rise to a slow and subtle progression of psychiatric disorders. The large delay between beginning and time of onset (diagnosis) may be explained by efficient compensatory mechanisms observed in brain metabolism that use optional pathways in highly redundant molecular interactions. To this end, research has to deal with mechanisms of learning and long-term memory formation, which involves (a) epigenetic changes, (b) altered neuronal activities, and (c) changes in neuron-glia communication. On the epigenetic level, apparently DNA-methylations are more stable than histone modifications, although both closely interact. Neuronal activities basically deliver digital information, which clearly can serve as basis for memory formation (LTP). However, research in this respect has long time neglected the importance of glia. They are more actively involved in the control of neuronal activities than thought before. They can both reinforce and inhibit neuronal activities by transducing neuronal information from frequency-encoded to amplitude and frequency-modulated calcium wave patterns spreading in the glial syncytium by use of gap junctions. In this way, they serve integrative functions. In conclusion, we are dealing with two concepts of encoding information that mutually control each other and synergize: a digital (neuronal) and a wave-like (glial) computing, forming neuron-glia functional units with inbuilt feedback loops to maintain balance of excitation and inhibition. To better understand mental illness, we have to gain more insight into the dynamics of adverse environmental impact on those cellular and molecular systems. This report summarizes existing knowledge and draws some outline about further research in molecular psychiatry.
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Affiliation(s)
- Peter J Gebicke-Haerter
- Medical Faculty Mannheim, Central Institute of Mental Health, Institute of Psychopharmacology, Heidelberg University Mannheim, Germany ; Progrs. de Farmacología y Inmunología, Facultad de Medicina, Universidad de Chile Santiago, Chile
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82
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Roesler R, Reolon GK, Maurmann N, Schwartsmann G, Schröder N, Amaral OB, Valvassori S, Quevedo J. A phosphodiesterase 4-controlled switch between memory extinction and strengthening in the hippocampus. Front Behav Neurosci 2014; 8:91. [PMID: 24672454 PMCID: PMC3955942 DOI: 10.3389/fnbeh.2014.00091] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 03/02/2014] [Indexed: 11/13/2022] Open
Abstract
Established fear-related memories can undergo phenomena such as extinction or reconsolidation when recalled. Extinction probably involves the creation of a new, competing memory trace that decreases fear expression, whereas reconsolidation can mediate memory maintenance, updating, or strengthening. The factors determining whether retrieval will initiate extinction, reconsolidation, or neither of these two processes include training intensity, duration of the retrieval session, and age of the memory. However, previous studies have not shown that the same behavioral protocol can be used to induce either extinction or reconsolidation and strengthening, depending on the pharmacological intervention used. Here we show that, within an experiment that leads to extinction in control rats, memory can be strengthened if rolipram, a selective inhibitor of phosphodiesterase type 4 (PDE4), is administered into the dorsal hippocampus immediately after retrieval. The memory-enhancing effect of rolipram lasted for at least 1 week, was blocked by the protein synthesis inhibitor anisomycin, and did not occur when drug administration was not paired with retrieval. These findings indicate that the behavioral outcome of memory retrieval can be pharmacologically switched from extinction to strengthening. The cAMP/protein kinase A (PKA) signaling pathway might be a crucial mechanism determining the fate of memories after recall.
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Affiliation(s)
- Rafael Roesler
- Laboratory of Neuropharmacology and Neural Tumor Biology, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul Porto Alegre, Brazil ; Cancer Research Laboratory, University Hospital Research Center (CPE-HCPA), Federal University of Rio Grande do Sul Porto Alegre, Brazil ; National Institute for Translational Medicine (INCT-TM) Porto Alegre, Brazil
| | - Gustavo K Reolon
- Laboratory of Neuropharmacology and Neural Tumor Biology, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul Porto Alegre, Brazil ; Cancer Research Laboratory, University Hospital Research Center (CPE-HCPA), Federal University of Rio Grande do Sul Porto Alegre, Brazil ; National Institute for Translational Medicine (INCT-TM) Porto Alegre, Brazil
| | - Natasha Maurmann
- Laboratory of Neuropharmacology and Neural Tumor Biology, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul Porto Alegre, Brazil ; Cancer Research Laboratory, University Hospital Research Center (CPE-HCPA), Federal University of Rio Grande do Sul Porto Alegre, Brazil ; National Institute for Translational Medicine (INCT-TM) Porto Alegre, Brazil
| | - Gilberto Schwartsmann
- Cancer Research Laboratory, University Hospital Research Center (CPE-HCPA), Federal University of Rio Grande do Sul Porto Alegre, Brazil ; National Institute for Translational Medicine (INCT-TM) Porto Alegre, Brazil ; Department of Internal Medicine, School of Medicine, Federal University of Rio Grande do Sul Porto Alegre, Brazil
| | - Nadja Schröder
- National Institute for Translational Medicine (INCT-TM) Porto Alegre, Brazil ; Neurobiology and Developmental Biology Laboratory, Faculty of Biosciences, Pontifical Catholic University Porto Alegre, Brazil
| | - Olavo B Amaral
- Leopoldo de Meis Institute of Medical Biochemistry, Federal University of Rio de Janeiro Rio de Janeiro, Brazil
| | - Samira Valvassori
- National Institute for Translational Medicine (INCT-TM) Porto Alegre, Brazil ; Laboratory of Neurosciences, Graduate Program in Health Sciences, Academic Unit of Health Sciences, University of Southern Santa Catarina (UNESC) Criciúma, Brazil
| | - João Quevedo
- National Institute for Translational Medicine (INCT-TM) Porto Alegre, Brazil ; Laboratory of Neurosciences, Graduate Program in Health Sciences, Academic Unit of Health Sciences, University of Southern Santa Catarina (UNESC) Criciúma, Brazil ; Center for Experimental Models in Psychiatry, Department of Psychiatry and Behavioral Sciences, The University of Texas Medical School at Houston Houston, TX, USA
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83
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Veyrac A, Besnard A, Caboche J, Davis S, Laroche S. The transcription factor Zif268/Egr1, brain plasticity, and memory. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 122:89-129. [PMID: 24484699 DOI: 10.1016/b978-0-12-420170-5.00004-0] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
The capacity to remember our past experiences and organize our future draws on a number of cognitive processes that allow our brain to form and store neural representations that can be recalled and updated at will. In the brain, these processes require mechanisms of neural plasticity in the activated circuits, brought about by cellular and molecular changes within the neurons activated during learning. At the cellular level, a wealth of experimental data accumulated in recent years provides evidence that signaling from synapses to nucleus and the rapid regulation of the expression of immediate early genes encoding inducible, regulatory transcription factors is a key step in the mechanisms underlying synaptic plasticity and the modification of neural networks required for the laying down of memories. In the activated neurons, these transcriptional events are thought to mediate the activation of selective gene programs and subsequent synthesis of proteins, leading to stable functional and structural remodeling of the activated networks, so that the memory can later be reactivated upon recall. Over the past few decades, novel insights have been gained in identifying key transcriptional regulators that can control the genomic response of synaptically activated neurons. Here, as an example of this approach, we focus on one such activity-dependent transcription factor, Zif268, known to be implicated in neuronal plasticity and memory formation. We summarize current knowledge about the regulation and function of Zif268 in different types of brain plasticity and memory processes.
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Affiliation(s)
- Alexandra Veyrac
- CNRS, Centre de Neurosciences Paris-Sud, UMR 8195, Orsay, France; Centre de Neurosciences Paris-Sud, Univ Paris-Sud, UMR 8195, Orsay, France
| | - Antoine Besnard
- Harvard Stem Cell Institute, Harvard Medical School, Center for Regenerative Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Jocelyne Caboche
- INSERM, UMRS 952, Physiopathologie des Maladies du Système Nerveux Central, Paris, France; CNRS, UMR7224, Physiopathologie des Maladies du Système Nerveux Central, Paris, France; UPMC University Paris 6, Paris, France
| | - Sabrina Davis
- CNRS, Centre de Neurosciences Paris-Sud, UMR 8195, Orsay, France; Centre de Neurosciences Paris-Sud, Univ Paris-Sud, UMR 8195, Orsay, France
| | - Serge Laroche
- CNRS, Centre de Neurosciences Paris-Sud, UMR 8195, Orsay, France; Centre de Neurosciences Paris-Sud, Univ Paris-Sud, UMR 8195, Orsay, France
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84
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Flavell CR, Lambert EA, Winters BD, Bredy TW. Mechanisms governing the reactivation-dependent destabilization of memories and their role in extinction. Front Behav Neurosci 2013; 7:214. [PMID: 24421762 PMCID: PMC3872723 DOI: 10.3389/fnbeh.2013.00214] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 12/13/2013] [Indexed: 12/28/2022] Open
Abstract
The extinction of learned associations has traditionally been considered to involve new learning, which competes with the original memory for control over behavior. However, a recent resurgence of interest in reactivation-dependent amnesia has revealed that the retrieval of fear-related memory (with what is essentially a brief extinction session) can result in its destabilization. This review discusses some of the cellular and molecular mechanisms that are involved in the destabilization of a memory following its reactivation and/or extinction, and investigates the evidence that extinction may involve both new learning as well as a partial destabilization-induced erasure of the original memory trace.
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Affiliation(s)
- Charlotte R Flavell
- Queensland Brain Institute, The University of Queensland Brisbane, QLD, Australia
| | - Elliot A Lambert
- Queensland Brain Institute, The University of Queensland Brisbane, QLD, Australia
| | - Boyer D Winters
- Department of Psychology, University of Guelph Guelph, ON, Canada
| | - Timothy W Bredy
- Queensland Brain Institute, The University of Queensland Brisbane, QLD, Australia
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85
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Penke Z, Morice E, Veyrac A, Gros A, Chagneau C, LeBlanc P, Samson N, Baumgärtel K, Mansuy IM, Davis S, Laroche S. Zif268/Egr1 gain of function facilitates hippocampal synaptic plasticity and long-term spatial recognition memory. Philos Trans R Soc Lond B Biol Sci 2013; 369:20130159. [PMID: 24298160 DOI: 10.1098/rstb.2013.0159] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
It is well established that Zif268/Egr1, a member of the Egr family of transcription factors, is critical for the consolidation of several forms of memory; however, it is as yet uncertain whether increasing expression of Zif268 in neurons can facilitate memory formation. Here, we used an inducible transgenic mouse model to specifically induce Zif268 overexpression in forebrain neurons and examined the effect on recognition memory and hippocampal synaptic transmission and plasticity. We found that Zif268 overexpression during the establishment of memory for objects did not change the ability to form a long-term memory of objects, but enhanced the capacity to form a long-term memory of the spatial location of objects. This enhancement was paralleled by increased long-term potentiation in the dentate gyrus of the hippocampus and by increased activity-dependent expression of Zif268 and selected Zif268 target genes. These results provide novel evidence that transcriptional mechanisms engaging Zif268 contribute to determining the strength of newly encoded memories.
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Affiliation(s)
- Zsuzsa Penke
- CNRS, Centre de Neurosciences Paris-Sud, UMR 8195, , Orsay 91405, France
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86
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Rudolph U, Möhler H. GABAA receptor subtypes: Therapeutic potential in Down syndrome, affective disorders, schizophrenia, and autism. Annu Rev Pharmacol Toxicol 2013; 54:483-507. [PMID: 24160694 DOI: 10.1146/annurev-pharmtox-011613-135947] [Citation(s) in RCA: 231] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The γ-aminobutyric acid (GABA) system plays a pivotal role in orchestrating the synchronicity of local networks and the functional coupling of different brain regions. Here we review the impact of the GABAA receptor subtypes on cognitive and emotional behavior, paying particular attention to five disease states: cognitive dysfunction and Down syndrome, anxiety disorders, depression, schizophrenia, and autism. Through the bidirectional modulation of tonic inhibition, α5-subunit-containing GABAA receptors permit the bidirectional modulation of cognitive processes, and a partial inverse agonist acting at the α5-subunit-containing GABAA receptor is in a clinical trial in individuals with Down syndrome. With regard to anxiety disorders, the viability of nonsedative anxiolytics based on the modulation of α2- and α3-subunit-containing GABAA receptors has been established in clinical proof-of-concept trials. Regarding the remaining three disease states, the GABA hypothesis of depression offers new options for antidepressant drug development; cognitive symptoms in schizophrenia are attributed to a cortical GABAergic deficit, and dysfunctional GABAergic inhibition is increasingly understood to contribute to the pathophysiology of autism spectrum disorders.
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Affiliation(s)
- Uwe Rudolph
- Laboratory of Genetic Neuropharmacology, McLean Hospital and Department of Psychiatry, Harvard Medical School, Belmont, Massachusetts 02478;
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87
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Kwapis JL, Helmstetter FJ. Does PKM(zeta) maintain memory? Brain Res Bull 2013; 105:36-45. [PMID: 24076105 DOI: 10.1016/j.brainresbull.2013.09.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 09/16/2013] [Accepted: 09/19/2013] [Indexed: 11/30/2022]
Abstract
Work on the long-term stability of memory has identified a potentially critical role for protein kinase Mzeta (PKMζ) in maintaining established memory. PKMζ, an autonomously active isoform of PKC, is hypothesized to sustain those changes that occurred during memory formation in order to preserve the memory engram over time. Initial studies investigating the role of PKMζ were largely successful in demonstrating a role for the kinase in memory maintenance; disrupting PKMζ activity with ζ-inhibitory peptide (ZIP) was successful in disrupting a variety of established associations in a number of key brain regions. More recent work, however, has questioned both the role of PKMζ in memory maintenance and the effectiveness of ZIP as a specific inhibitor of PKMζ activity. Here, we outline the research both for and against the idea that PKMζ is a memory maintenance mechanism and discuss how these two lines of research can be reconciled. We conclude by proposing a number of studies that would help to clarify the role of PKMζ in memory and define other mechanisms the brain may use to maintain memory.
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Affiliation(s)
- Janine L Kwapis
- Department of Psychology, University of Wisconsin-Milwaukee, 2441 E. Hartford Ave., Milwaukee, WI 53211, USA
| | - Fred J Helmstetter
- Department of Psychology, University of Wisconsin-Milwaukee, 2441 E. Hartford Ave., Milwaukee, WI 53211, USA.
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88
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Blake MG, Boccia MM, Krawczyk MC, Baratti CM. Hippocampal α7-nicotinic cholinergic receptors modulate memory reconsolidation: a potential strategy for recovery from amnesia. Neurobiol Learn Mem 2013; 106:193-203. [PMID: 24036397 DOI: 10.1016/j.nlm.2013.09.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 07/29/2013] [Accepted: 09/02/2013] [Indexed: 11/16/2022]
Abstract
When subjects are exposed to new learning experiences, the novel information could be acquired and eventually stored through memory consolidation process. The exposure of mice to a novel experience (a hole-board) after being trained in an inhibitory avoidance apparatus is followed by impaired performance of the avoidance memory in subsequent tests. The same impairing effect is produced when mice are exposed to the novel environment after the reactivation of the avoidance memory. This interfering effect is due to impaired consolidation or reconsolidation of the avoidance memory. The administration of the α7-nicotinic receptor agonist choline (Ch) in the dorsal hippocampus (0.8 μg/hippocampus) immediately after the inhibitory avoidance memory reactivation, allowed memory recovery. This effect of Ch was time-dependent, and retention performance was not affected in drug-treated mice that were not subjected to memory reactivation, suggesting that the effects on performance are not due to non-specific effects of the drug. The effects of Ch also depended on the age of the reactivated memory. Altogether, our results suggest that Ch exerts its effects by modulating memory reconsolidation, and that the memory impairment induced by new learning is a memory expression failure and not a storage deficit. Therefore, reconsolidation, among other functions, might serve to change whether a memory will be expressed in later tests. Summarizing, our results open new avenues about the behavioral significance and the physiological functions of memory reconsolidation, providing new strategies for recovering memories from some types of amnesia.
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Affiliation(s)
- M G Blake
- Laboratorio de Neurofarmacología de los Procesos de Memoria, Cátedra de Farmacología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina.
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89
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Asok A, Schreiber WB, Jablonski SA, Rosen JB, Stanton ME. Egr-1 increases in the prefrontal cortex following training in the context preexposure facilitation effect (CPFE) paradigm. Neurobiol Learn Mem 2013; 106:145-53. [PMID: 23973447 DOI: 10.1016/j.nlm.2013.08.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 08/09/2013] [Accepted: 08/16/2013] [Indexed: 01/09/2023]
Abstract
The context pre-exposure facilitation effect (CPFE) is a modified form of standard contextual fear conditioning that dissociates learning about the context during a preexposure phase from learning the context-shock association during an immediate shock training phase conducted on separate days. Fear conditioning in the CPFE is an associative process in which only animals that are preexposed to the same context they are later given an immediate shock in demonstrate freezing when tested for conditioned fear memory. Previous research has shown that the hippocampus and amygdala are necessary for different phases of the CPFE, but whether other brain regions are also involved is unknown. The present study examined expression of the immediate-early gene early growth response gene 1 (Egr-1; also called Zif268, Ngfi-a, Krox-24) in the dorsal hippocampus, lateral nucleus of the amygdala, retrosplenial cortex, and several prefrontal cortex regions (infralimbic and prelimbic medial prefrontal cortex, anterior cingulate, and orbitofrontal cortex) following each phase of the CPFE in juvenile rats. Animals preexposed to the conditioning context displayed fear conditioned freezing during a retention test whereas rats preexposed to an alternate context did not. Following context preexposure, Egr-1 mRNA was elevated in context and alternate context exposed animals compared to home-cage control rats in almost all regions analyzed. Following the context-shock training phase, fear conditioned rats displayed significantly more Egr-1 mRNA expression in the infralimbic, prelimbic, and orbitofrontal cortices compared to the alternate context preexposed control rats. These differences in Egr-1 expression were not found in amygdala between the preexposed context and alternate context rats. No sex differences were observed following preexposure or training in any regions analyzed. The findings suggest that increased expression of Egr-1 within the prefrontal cortex is associated with contextual fear conditioning in the CPFE paradigm.
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Affiliation(s)
- Arun Asok
- Department of Psychology, University of Delaware, Newark, DE 19716, USA
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90
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Reactivation enables memory updating, precision-keeping and strengthening: Exploring the possible biological roles of reconsolidation. Neuroscience 2013; 244:42-8. [DOI: 10.1016/j.neuroscience.2013.04.005] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 04/03/2013] [Accepted: 04/04/2013] [Indexed: 11/18/2022]
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91
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Reconsolidation and extinction of an appetitive pavlovian memory. Neurobiol Learn Mem 2013; 104:25-31. [PMID: 23639449 DOI: 10.1016/j.nlm.2013.04.009] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 04/19/2013] [Accepted: 04/19/2013] [Indexed: 01/20/2023]
Abstract
When memories are retrieved, they can enter a labile state during which the memory may be modified and subsequently restabilized through the process of reconsolidation. However, this does not occur in all situations, and certain "boundary conditions" determine whether a memory will undergo reconsolidation. Naïve male lister hooded rats were trained for 5 days to press a lever in order to retrieve a food reward associated with a pavlovian light stimulus. Three days post-training, animals were injected with either MK-801 (0.1 mgkg(-1); i.p.) or saline vehicle, 30 min before they were placed back into the training context for a retrieval session. Lever pressing was reinforced only by the light stimulus and was restricted to either 10, 30 or 50 presentations of the light conditioned stimulus. After 48 h, animals were again returned to the boxes and light-reinforced lever-pressing activity was recorded. MK-801-treated animals in the 10CS group significantly reduced lever pressing at test, compared to saline controls. In contrast, MK-801-treated rats in the 50CS group demonstrated a significant increase. There was no effect of MK-801 in the 30CS group. Additionally, there were no effects of MK-801 in an analogous, pure instrumental, setting when the cue lights were omitted. The opposing effects of MK-801 under different parametric conditions likely reflect impairments of appetitive pavlovian memory reconsolidation and extinction, respectively. These results demonstrate a competition between reconsolidation and extinction. However, there are also conditions under which MK-801 fails to impair either process.
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92
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Jarome TJ, Helmstetter FJ. The ubiquitin-proteasome system as a critical regulator of synaptic plasticity and long-term memory formation. Neurobiol Learn Mem 2013; 105:107-16. [PMID: 23623827 DOI: 10.1016/j.nlm.2013.03.009] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 03/25/2013] [Accepted: 03/26/2013] [Indexed: 02/01/2023]
Abstract
Numerous studies have supported the idea that de novo protein synthesis is critical for synaptic plasticity and normal long-term memory formation. This requirement for protein synthesis has been shown for several different types of fear memories, exists in multiple brain regions and circuits, and is necessary for different stages of memory creation and storage. However, evidence has recently begun to accumulate suggesting that protein degradation through the ubiquitin-proteasome system is an equally important regulator of memory formation. Here we review those recent findings on protein degradation and memory formation and stability and propose a model explaining how protein degradation may be contributing to various aspects of memory and synaptic plasticity. We conclude that protein degradation may be the major factor regulating many of the molecular processes that we know are important for fear memory formation and stability in the mammalian brain.
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Affiliation(s)
- Timothy J Jarome
- Department of Psychology, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201, USA
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93
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Auber A, Tedesco V, Jones CE, Monfils MH, Chiamulera C. Post-retrieval extinction as reconsolidation interference: methodological issues or boundary conditions? Psychopharmacology (Berl) 2013; 226:631-47. [PMID: 23404065 PMCID: PMC3682675 DOI: 10.1007/s00213-013-3004-1] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2012] [Accepted: 01/20/2013] [Indexed: 12/30/2022]
Abstract
Memories that are emotionally arousing generally promote the survival of species; however, the systems that modulate emotional learning can go awry, resulting in pathological conditions such as post-traumatic stress disorders, phobias, and addiction. Understanding the conditions under which emotional memories can be targeted is a major research focus as the potential to translate these methods into clinical populations carries important implications. It has been demonstrated that both fear and drug-related memories can be destabilised at their retrieval and require reconsolidation to be maintained. Therefore, memory reconsolidation offers a potential target period during which the aberrant memories underlying psychiatric disorders can be disrupted. Monfils et al. (Science 324:951-955, 2009) have shown for the first time that safe information provided through an extinction session after retrieval (during the reconsolidation window) may update the original memory trace and prevent the return of fear in rats. In recent years, several authors have then tested the effect of post-retrieval extinction on reconsolidation of either fear or drug-related memories in both laboratory animals and humans. In this article, we review the literature on post-reactivation extinction, discuss the differences across studies on the methodological ground, and review the potential boundary conditions that may explain existing discrepancies and limit the potential application of post-reactivation extinction approaches.
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Affiliation(s)
- Alessia Auber
- Neuropsychopharmacology Lab., Sect. Pharmacology, Department Public Health and Community Medicine, Univ. of Verona, Verona, Italy.
| | - Vincenzo Tedesco
- Neuropsychopharmacology Lab., Sect. Pharmacology, Dept. Public Health and Community Medicine, Univ. of Verona, Verona, Italy
| | | | | | - Christian Chiamulera
- Neuropsychopharmacology Lab., Sect. Pharmacology, Dept. Public Health and Community Medicine, Univ. of Verona, Verona, Italy
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94
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Yang C, Liu JF, Chai BS, Fang Q, Chai N, Zhao LY, Xue YX, Luo YX, Jian M, Han Y, Shi HS, Lu L, Wu P, Wang JS. Stress within a restricted time window selectively affects the persistence of long-term memory. PLoS One 2013; 8:e59075. [PMID: 23544051 PMCID: PMC3609809 DOI: 10.1371/journal.pone.0059075] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 02/11/2013] [Indexed: 12/02/2022] Open
Abstract
The effects of stress on emotional memory are distinct and depend on the stages of memory. Memory undergoes consolidation and reconsolidation after acquisition and retrieval, respectively. Stress facilitates the consolidation but disrupts the reconsolidation of emotional memory. Previous research on the effects of stress on memory have focused on long-term memory (LTM) formation (tested 24 h later), but the effects of stress on the persistence of LTM (tested at least 1 week later) are unclear. Recent findings indicated that the persistence of LTM requires late-phase protein synthesis in the dorsal hippocampus. The present study investigated the effect of stress (i.e., cold water stress) during the late phase after the acquisition and retrieval of contextual fear memory in rats. We found that stress and corticosterone administration during the late phase (12 h) after acquisition, referred to as late consolidation, selectively enhanced the persistence of LTM, whereas stress during the late phase (12 h) after retrieval, referred to as late reconsolidation, selectively disrupted the restabilized persistence of LTM. Moreover, the effects of stress on the persistence of LTM were blocked by the corticosterone synthesis inhibitor metyrapone, which was administered before stress, suggesting that the glucocorticoid system is involved in the effects of stress on the persistence of LTM. We conclude that stress within a restricted time window after acquisition or retrieval selectively affects the persistence of LTM and depends on the glucocorticoid system.
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Affiliation(s)
- Chang Yang
- Affiliated Hospital and School of Pharmacy of Guiyang Medical University, Guiyang, China
| | - Jian-Feng Liu
- National Institute on Drug Dependence, Peking University, Beijing, China
| | - Bai-Sheng Chai
- Affiliated Hospital and School of Pharmacy of Guiyang Medical University, Guiyang, China
| | - Qin Fang
- Affiliated Hospital and School of Pharmacy of Guiyang Medical University, Guiyang, China
| | - Ning Chai
- Institute of Mental Health, Hebei Medical University, Shijiazhuang, China
- Hebei Brain Ageing and Cognitive Neuroscience Laboratory, Hebei Medical University, Shijiazhuang, China
| | - Li-Yan Zhao
- National Institute on Drug Dependence, Peking University, Beijing, China
| | - Yan-Xue Xue
- National Institute on Drug Dependence, Peking University, Beijing, China
| | - Yi-Xiao Luo
- National Institute on Drug Dependence, Peking University, Beijing, China
| | - Min Jian
- National Institute on Drug Dependence, Peking University, Beijing, China
| | - Ying Han
- National Institute on Drug Dependence, Peking University, Beijing, China
| | - Hai-Shui Shi
- Department of Biochemistry and Molecular Biology, Basic Medical College, Hebei Medical University, Shijiazhuang, China
| | - Lin Lu
- National Institute on Drug Dependence, Peking University, Beijing, China
| | - Ping Wu
- National Institute on Drug Dependence, Peking University, Beijing, China
- * E-mail: (PW); (JSW)
| | - Ji-Shi Wang
- Affiliated Hospital and School of Pharmacy of Guiyang Medical University, Guiyang, China
- * E-mail: (PW); (JSW)
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95
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Díaz-Mataix L, Ruiz Martinez RC, Schafe GE, LeDoux JE, Doyère V. Detection of a temporal error triggers reconsolidation of amygdala-dependent memories. Curr Biol 2013; 23:467-72. [PMID: 23453952 DOI: 10.1016/j.cub.2013.01.053] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 12/23/2012] [Accepted: 01/18/2013] [Indexed: 11/15/2022]
Abstract
Updating memories is critical for adaptive behaviors, but the rules and mechanisms governing that process are still not well defined. During a limited time window, the reactivation of consolidated aversive memories triggers memory lability and induces a plasticity-dependent reconsolidation process in the lateral nucleus of amygdala (LA) [1-5]. However, whether new information is necessary for initiating reconsolidation is not known. Here we show that changing the temporal relationship between the conditioned stimulus (CS) and unconditioned stimulus (US) during reactivation is sufficient to trigger synaptic plasticity and reconsolidation of an aversive memory in the LA. These findings demonstrate that time is a core part of the CS-US association and that new information must be presented during reactivation in order to trigger LA-dependent reconsolidation processes. In sum, this study provides new basic knowledge about the precise rules governing memory reconsolidation of aversive memories that might be used to treat traumatic memories.
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96
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Abstract
One of the most exciting discoveries in the learning and memory field in the past two decades is the observation that active regulation of gene expression is necessary for experience to trigger lasting functional and behavioral change, in a wide variety of species, including humans. Thus, as opposed to the traditional view of 'nature' (genes) being separate from 'nurture' (environment and experience), it is now clear that experience actively drives alterations in central nervous system (CNS) gene expression in an ongoing fashion, and that the resulting transcriptional changes are necessary for experience to trigger altered long-term behavior. In parallel over the past decade, epigenetic mechanisms, including regulation of chromatin structure and DNA methylation, have been shown to be potent regulators of gene transcription in the CNS. In this review, we describe data supporting the hypothesis that epigenetic molecular mechanisms, especially DNA methylation and demethylation, drive long-term behavioral change through active regulation of gene transcription in the CNS. Specifically, we propose that epigenetic molecular mechanisms underlie the formation and stabilization of context- and cue-triggered fear conditioning based in the hippocampus and amygdala, a conclusion reached in a wide variety of studies using laboratory animals. Given the relevance of cued and contextual fear conditioning to post-traumatic stress, by extension we propose that these mechanisms may contribute to post-traumatic stress disorder (PTSD) in humans. Moreover, we speculate that epigenetically based pharmacotherapy may provide a new avenue of drug treatment for PTSD-related cognitive and behavioral function.
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Affiliation(s)
- Iva B Zovkic
- Department of Neurobiology, Evelyn F. McKnight Brain Institute, University of Alabama, Birmingham, AL, USA
| | - J David Sweatt
- Department of Neurobiology, Evelyn F. McKnight Brain Institute, University of Alabama, Birmingham, AL, USA,Department of Neurobiology, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, 1010 Shelby Building, 1825 University Boulevard, Birmingham, AL 35294-2182, USA, Tel: +205 975 5196, Fax: +205 934 6571, E-mail:
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97
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Lee JLC, Hynds RE. Divergent cellular pathways of hippocampal memory consolidation and reconsolidation. Hippocampus 2012. [PMID: 23197404 DOI: 10.1002/hipo.22083] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The reconsolidation of memories after their retrieval involves cellular mechanisms that recapitulate much of the initial consolidation process. However, we have previously demonstrated that there are independent cellular mechanisms of consolidation and reconsolidation in the dorsal hippocampus for contextual fear memories. Expression of BDNF was required for consolidation, while Zif268 expression was necessary for reconsolidation. Given the dichotomy between the obvious mechanistic similarity and notable dissociations between consolidation and reconsolidation, we sought to determine whether the separation at the level of gene expression reflected either parallel and independent upstream signaling pathways, or common upstream mechanisms that diverge by the level of transcriptional activation. Here we show that while consolidation and reconsolidation are commonly dependent upon NMDA receptor activation in the dorsal hippocampus there is a double dissociation between the effects of the MEK inhibitor U0126 and the IKK inhibitor sulfasalazine. Moreover, rescue experiments and western blot analyses show that there are functional NMDA receptor-ERK1-BDNF and NMDA receptor-IKKα-Zif268 pathways for consolidation and reconsolidation, respectively. Therefore, there are divergent pathways of hippocampal memory consolidation and reconsolidation, involving commonality at the cell surface, but separable downstream kinase cascades and transcriptional regulation.
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Affiliation(s)
- Jonathan L C Lee
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, United Kingdom.
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98
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Abstract
It is well established that the activity of chromatin-modifying enzymes is crucial for regulating gene expression associated with hippocampal-dependent memories. However, very little is known about how these epigenetic mechanisms influence the formation of cortically dependent memory, particularly when there is competition between opposing memory traces, such as that which occurs during the acquisition and extinction of conditioned fear. Here we demonstrate, in C57BL/6 mice, that the activity of p300/CBP-associated factor (PCAF) within the infralimbic prefrontal cortex is required for long-term potentiation and is necessary for the formation of memory associated with fear extinction, but not for fear acquisition. Further, systemic administration of the PCAF activator SPV106 enhances memory for fear extinction and prevents fear renewal. The selective influence of PCAF on fear extinction is mediated, in part, by a transient recruitment of the repressive transcription factor ATF4 to the promoter of the immediate early gene zif268, which competitively inhibits its expression. Thus, within the context of fear extinction, PCAF functions as a transcriptional coactivator, which may facilitate the formation of memory for fear extinction by interfering with reconsolidation of the original memory trace.
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99
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Besnard A, Caboche J, Laroche S. Reconsolidation of memory: A decade of debate. Prog Neurobiol 2012; 99:61-80. [PMID: 22877586 DOI: 10.1016/j.pneurobio.2012.07.002] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Revised: 06/13/2012] [Accepted: 07/08/2012] [Indexed: 10/28/2022]
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100
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Gisquet-Verrier P, Riccio DC. Memory reactivation effects independent of reconsolidation. Learn Mem 2012; 19:401-9. [PMID: 22904371 DOI: 10.1101/lm.026054.112] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Memory reactivation is an important process resulting from reexposure to salient training-related information whereby a memory is brought from an inactive to an active state. Reactivation is the first stage of memory retrieval but can result from the exposure to salient cues without any behavioral output. Such cue-induced reactivation, although frequently used by neuroscientists to study reconsolidation, has seldom been considered as a process in its own right and studied as such. This review presents arguments indicating that memory reactivation has two main consequences: (1) to enhance the accessibility of the target memory and (2) to make the memory malleable. Accordingly, reactivation creates a transient state during which the content of the memory is easily accessible and can be modified and/or updated. As both of these aspects can be observed shortly after memory reactivation, this review emphasizes that reconsolidation is not necessarily required for these processes and calls attention to reactivation as a factor in the dynamics of the memory.
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