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Allen MT. Weaker situations: Uncertainty reveals individual differences in learning: Implications for PTSD. COGNITIVE, AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2023:10.3758/s13415-023-01077-5. [PMID: 36944865 DOI: 10.3758/s13415-023-01077-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/07/2023] [Indexed: 03/23/2023]
Abstract
Few individuals who experience trauma develop posttraumatic stress disorder (PTSD). Therefore, the identification of individual differences that signal increased risk for PTSD is important. Lissek et al. (2006) proposed using a weak rather than a strong situation to identify individual differences. A weak situation involves less-salient cues as well as some degree of uncertainty, which reveal individual differences. A strong situation involves salient cues with little uncertainty, which produce consistently strong responses. Results from fear conditioning studies that support this hypothesis are discussed briefly. This review focuses on recent findings from three learning tasks: classical eyeblink conditioning, avoidance learning, and a computer-based task. These tasks are interpreted as weaker learning situations in that they involve some degree of uncertainty. Individual differences in learning based on behavioral inhibition, which is a risk factor for PTSD, are explored. Specifically, behaviorally inhibited individuals and rodents (i.e., Wistar Kyoto rats), as well as individuals expressing PTSD symptoms, exhibit enhanced eyeblink conditioning. Behaviorally inhibited rodents also demonstrate enhanced avoidance responding (i.e., lever pressing). Both enhanced eyeblink conditioning and avoidance are most evident with schedules of partial reinforcement. Behaviorally inhibited individuals also performed better on reward and punishment trials than noninhibited controls in a probabilistic category learning task. Overall, the use of weaker situations with uncertain relationships may be more ecologically valid than learning tasks in which the aversive event occurs on every trial and may provide more sensitivity for identifying individual differences in learning for those at risk for, or expressing, PTSD symptoms.
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Affiliation(s)
- M Todd Allen
- School of Psychological Sciences, University of Northern Colorado, Greeley, CO, USA.
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2
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Laughlin LC, Moloney DM, Samels SB, Sears RM, Cain CK. Reducing shock imminence eliminates poor avoidance in rats. ACTA ACUST UNITED AC 2020; 27:270-274. [PMID: 32540916 PMCID: PMC7301752 DOI: 10.1101/lm.051557.120] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 04/16/2020] [Indexed: 11/25/2022]
Abstract
In signaled active avoidance (SigAA), rats learn to suppress Pavlovian freezing and emit actions to remove threats and prevent footshocks. SigAA is critical for understanding aversively motivated instrumental behavior and anxiety-related active coping. However, with standard protocols ∼25% of rats exhibit high freezing and poor avoidance. This has dampened enthusiasm for the paradigm and stalled progress. We demonstrate that reducing shock imminence with long-duration warning signals leads to greater freezing suppression and perfect avoidance in all subjects. This suggests that instrumental SigAA mechanisms evolved to cope with distant harm and protocols that promote inflexible Pavlovian reactions are poorly designed to study avoidance.
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Affiliation(s)
- Lindsay C Laughlin
- Nathan Kline Institute for Psychiatric Research, Emotional Brain Institute, Orangeburg, New York 10962, USA
| | - Danielle M Moloney
- NYU School of Medicine, Department of Child and Adolescent Psychiatry, New York, New York 10016, USA.,Nathan Kline Institute for Psychiatric Research, Emotional Brain Institute, Orangeburg, New York 10962, USA
| | - Shanna B Samels
- Nathan Kline Institute for Psychiatric Research, Emotional Brain Institute, Orangeburg, New York 10962, USA
| | - Robert M Sears
- NYU School of Medicine, Department of Child and Adolescent Psychiatry, New York, New York 10016, USA.,Nathan Kline Institute for Psychiatric Research, Emotional Brain Institute, Orangeburg, New York 10962, USA
| | - Christopher K Cain
- NYU School of Medicine, Department of Child and Adolescent Psychiatry, New York, New York 10016, USA.,Nathan Kline Institute for Psychiatric Research, Emotional Brain Institute, Orangeburg, New York 10962, USA
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3
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Haaker J, Maren S, Andreatta M, Merz CJ, Richter J, Richter SH, Meir Drexler S, Lange MD, Jüngling K, Nees F, Seidenbecher T, Fullana MA, Wotjak CT, Lonsdorf TB. Making translation work: Harmonizing cross-species methodology in the behavioural neuroscience of Pavlovian fear conditioning. Neurosci Biobehav Rev 2019; 107:329-345. [PMID: 31521698 PMCID: PMC7822629 DOI: 10.1016/j.neubiorev.2019.09.020] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 07/08/2019] [Accepted: 09/11/2019] [Indexed: 12/22/2022]
Abstract
Translational neuroscience bridges insights from specific mechanisms in rodents to complex functions in humans and is key to advance our general understanding of central nervous function. A prime example of translational research is the study of cross-species mechanisms that underlie responding to learned threats, by employing Pavlovian fear conditioning protocols in rodents and humans. Hitherto, evidence for (and critique of) these cross-species comparisons in fear conditioning research was based on theoretical viewpoints. Here, we provide a perspective to substantiate these theoretical concepts with empirical considerations of cross-species methodology. This meta-research perspective is expected to foster cross-species comparability and reproducibility to ultimately facilitate successful transfer of results from basic science into clinical applications.
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Affiliation(s)
- Jan Haaker
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| | - Stephen Maren
- Department of Psychological and Brain Sciences and Institute for Neuroscience, Texas A&M University, College Station, TX, 77843, USA
| | - Marta Andreatta
- Department of Psychology, University of Würzburg, Würzburg, Germany; Department of Psychology, Education & Child Studies, Erasmus University Rotterdam, Netherlands
| | - Christian J Merz
- Ruhr University Bochum, Faculty of Psychology, Institute of Cognitive Neuroscience, Department of Cognitive Psychology, Germany
| | - Jan Richter
- Department of Biological and Clinical Psychology/Psychotherapy, University of Greifswald, Greifswald, Germany
| | - S Helene Richter
- Department of Behavioural Biology, University of Münster, Münster, Germany
| | - Shira Meir Drexler
- Ruhr University Bochum, Faculty of Psychology, Institute of Cognitive Neuroscience, Department of Cognitive Psychology, Germany
| | - Maren D Lange
- Institute of Physiology I, University of Münster, Münster, Germany
| | - Kay Jüngling
- Institute of Physiology I, University of Münster, Münster, Germany
| | - Frauke Nees
- Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | | | - Miquel A Fullana
- Institute of Neurosciences, Hospital Clinic, Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Barcelona, Spain
| | - Carsten T Wotjak
- Neuronal Plasticity Research Group, Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - Tina B Lonsdorf
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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4
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Naderi R, Esmaeili-Mahani S, Abbasnejad M. Extracellular calcium influx through L-type calcium channels, intracellular calcium currents and extracellular signal-regulated kinase signaling are involved in the abscisic acid-induced precognitive and anti-anxiety effects. Biomed Pharmacother 2019; 109:582-588. [DOI: 10.1016/j.biopha.2018.10.141] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Revised: 10/14/2018] [Accepted: 10/24/2018] [Indexed: 10/27/2022] Open
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5
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Mechanisms of fear learning and extinction: synaptic plasticity-fear memory connection. Psychopharmacology (Berl) 2019; 236:163-182. [PMID: 30415278 PMCID: PMC6374177 DOI: 10.1007/s00213-018-5104-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 11/02/2018] [Indexed: 12/21/2022]
Abstract
RATIONALE The ability to memorize threat-associated cues and subsequently react to them, exhibiting escape or avoidance responses, is an essential, often life-saving behavioral mechanism that can be experimentally studied using the fear (threat) conditioning training paradigm. Presently, there is substantial evidence supporting the Synaptic Plasticity-Memory (SPM) hypothesis in relation to the mechanisms underlying the acquisition, retention, and extinction of conditioned fear memory. OBJECTIVES The purpose of this review article is to summarize findings supporting the SPM hypothesis in the context of conditioned fear control, applying the set of criteria and tests which were proposed as necessary to causally link lasting changes in synaptic transmission in corresponding neural circuits to fear memory acquisition and extinction with an emphasis on their pharmacological diversity. RESULTS The mechanisms of synaptic plasticity in fear circuits exhibit complex pharmacological profiles and satisfy all four SPM criteria-detectability, anterograde alteration, retrograde alteration, and mimicry. CONCLUSION The reviewed findings, accumulated over the last two decades, provide support for both necessity and sufficiency of synaptic plasticity in fear circuits for fear memory acquisition and retention, and, in part, for fear extinction, with the latter requiring additional experimental work.
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6
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Gil-Jardiné C, Al Joboory S, Jammes JTS, Durand G, Ribéreau-Gayon R, Galinski M, Salmi LR, Revel P, Régis CA, Valdenaire G, Poulet E, Tazarourte K, Lagarde E. Prevention of post-concussion-like symptoms in patients presenting at the emergency room, early single eye movement desensitization, and reprocessing intervention versus usual care: study protocol for a two-center randomized controlled trial. Trials 2018; 19:555. [PMID: 30314512 PMCID: PMC6186089 DOI: 10.1186/s13063-018-2902-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 09/04/2018] [Indexed: 01/04/2023] Open
Abstract
Background Recent data suggest that 10–20% of injury patients will suffer for several months after the event from diverse symptoms, generally referred to as post-concussion-like symptoms (PCLS), which will lead to a decline in quality of life. A preliminary randomized control trial suggested that this condition may be induced by the stress experienced during the event or emergency room (ER) stay and can be prevented in up to 75% of patients with a single, early, short eye movement desensitization and reprocessing (EMDR) psychotherapeutic session delivered in the ER. The protocol of the SOFTER 3 study was designed to compare the impact on 3-month PCLS of early EMDR intervention and usual care in patients presenting at the ER. Secondary outcomes included 3-month post-traumatic stress disorder, 12-month PCLS, self-reported stress at the ER, self-assessed recovery expectation at discharge and 3 months, and self-reported chronic pain at discharge and 3 months. Methods This is a two-group, open-label, multicenter, comparative, randomized controlled trial with 3- and 12-month phone follow-up for reports of persisting symptoms (PCLS and post-traumatic stress disorder). Those eligible for inclusion were adults (≥18 years old) presenting at the ER departments of the University Hospital of Bordeaux and University Hospital of Lyon, assessed as being at high risk of PCLS using a three-item scoring rule. The intervention groups were a (1) EMDR Recent Traumatic Episode Protocol intervention performed by a trained psychologist during ER stay or (2) usual care. The number of patients to be enrolled in each group was 223 to evidence a 15% decrease in PCLS prevalence in the EMDR group. Discussion In 2012, the year of the last national survey in France, 10.6 million people attended the ER, some of whom did so several times since 18 million visits were recorded in the same year. The SOFTER 3 study therefore addresses a major public health challenge. Trial registration Clinical Trials. NCT03400813. Registered 17 January 2018 – retrospectively registered. Electronic supplementary material The online version of this article (10.1186/s13063-018-2902-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Cédric Gil-Jardiné
- University Hospital of Bordeaux, Pole of Emergency Medicine, Bordeaux, France. .,INSERM, ISPED, Bordeaux Population Health research center INSERM U1219 - "Injury Epidemiology Transport Occupation" team, Bordeaux Cedex, France. .,Emergency Department, University Hospital of Bordeaux, Pellegrin Hospital, Place Amélie Raba-Léon, 33000, Bordeaux, France. .,Bordeaux University Hospital, Centre Hospitalier Universitaire de Bordeaux, 12 rue Dubernat, 33400, Talence, France.
| | | | | | - Guillaume Durand
- Department of Emergency Medicine, University Hospital Edouard Herriot, Hospices civils de Lyon, Lyon, France.,University Hospital, Claude Bernard University, Lyon, France
| | - Régis Ribéreau-Gayon
- INSERM, ISPED, Bordeaux Population Health research center INSERM U1219 - "Injury Epidemiology Transport Occupation" team, Bordeaux Cedex, France.,University Hospital of Bordeaux, Pole of Medicine, Bordeaux, France
| | - Michel Galinski
- University Hospital of Bordeaux, Pole of Emergency Medicine, Bordeaux, France.,INSERM, ISPED, Bordeaux Population Health research center INSERM U1219 - "Injury Epidemiology Transport Occupation" team, Bordeaux Cedex, France
| | - Louis-Rachid Salmi
- INSERM, ISPED, Bordeaux Population Health research center INSERM U1219 - "Injury Epidemiology Transport Occupation" team, Bordeaux Cedex, France.,University Hospital of Bordeaux, Pole of Public Health, Bordeaux, France
| | - Philippe Revel
- University Hospital of Bordeaux, Pole of Emergency Medicine, Bordeaux, France.,INSERM, ISPED, Bordeaux Population Health research center INSERM U1219 - "Injury Epidemiology Transport Occupation" team, Bordeaux Cedex, France
| | | | - Guillaume Valdenaire
- University Hospital of Bordeaux, Pole of Emergency Medicine, Bordeaux, France.,INSERM, ISPED, Bordeaux Population Health research center INSERM U1219 - "Injury Epidemiology Transport Occupation" team, Bordeaux Cedex, France
| | - Emmanuel Poulet
- University Hospital, Claude Bernard University, Lyon, France.,Department of Psychiatry, University Hospital Edouard Herriot, Hospices civils de Lyon, Lyon, France
| | - Karim Tazarourte
- Department of Emergency Medicine, University Hospital Edouard Herriot, Hospices civils de Lyon, Lyon, France.,EA 7425 Hesper University Hospital, Claude Bernard University, Lyon, France
| | - Emmanuel Lagarde
- INSERM, ISPED, Bordeaux Population Health research center INSERM U1219 - "Injury Epidemiology Transport Occupation" team, Bordeaux Cedex, France
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7
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Kim SH, Park YR, Lee B, Choi B, Kim H, Kim CH. Reduction of Cav1.3 channels in dorsal hippocampus impairs the development of dentate gyrus newborn neurons and hippocampal-dependent memory tasks. PLoS One 2017; 12:e0181138. [PMID: 28715454 PMCID: PMC5513490 DOI: 10.1371/journal.pone.0181138] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Accepted: 06/27/2017] [Indexed: 12/12/2022] Open
Abstract
Cav1.3 has been suggested to mediate hippocampal neurogenesis of adult mice and contribute to hippocampal-dependent learning and memory processes. However, the mechanism of Cav1.3 contribution in these processes is unclear. Here, roles of Cav1.3 of mouse dorsal hippocampus during newborn cell development were examined. We find that knock-out (KO) of Cav1.3 resulted in the reduction of survival of newborn neurons at 28 days old after mitosis. The retroviral eGFP expression showed that both dendritic complexity and the number and length of mossy fiber bouton (MFB) filopodia of newborn neurons at ≥ 14 days old were significantly reduced in KO mice. Both contextual fear conditioning (CFC) and object-location recognition tasks were impaired in recent (1 day) memory test while passive avoidance task was impaired only in remote (≥ 20 days) memory in KO mice. Results using adeno-associated virus (AAV)-mediated Cav1.3 knock-down (KD) or retrovirus-mediated KD in dorsal hippocampal DG area showed that the recent memory of CFC was impaired in both KD mice but the remote memory was impaired only in AAV KD mice, suggesting that Cav1.3 of mature neurons play important roles in both recent and remote CFC memory while Cav1.3 in newborn neurons is selectively involved in the recent CFC memory process. Meanwhile, AAV KD of Cav1.3 in ventral hippocampal area has no effect on the recent CFC memory. In conclusion, the results suggest that Cav1.3 in newborn neurons of dorsal hippocampus is involved in the survival of newborn neurons while mediating developments of dendritic and axonal processes of newborn cells and plays a role in the memory process differentially depending on the stage of maturation and the type of learning task.
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Affiliation(s)
- Su-Hyun Kim
- Center for Neuroscience, Korea Institute of Science and Technology, Seoul, Korea
- Neuroscience Program, Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology, Seoul, Korea
| | - Ye-Ryoung Park
- Center for Neuroscience, Korea Institute of Science and Technology, Seoul, Korea
- Neuroscience Program, Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology, Seoul, Korea
| | - Boyoung Lee
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon, Korea
| | - Byungil Choi
- Department of Anatomy and Division of Brain Korea 21 Biomedical Science, College of Medicine, Korea University, Seoul, Korea
| | - Hyun Kim
- Department of Anatomy and Division of Brain Korea 21 Biomedical Science, College of Medicine, Korea University, Seoul, Korea
| | - Chong-Hyun Kim
- Center for Neuroscience, Korea Institute of Science and Technology, Seoul, Korea
- Neuroscience Program, Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology, Seoul, Korea
- * E-mail:
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8
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Briggs JF, Fava DA. Immediate Extinction Attenuates Spontaneous Recovery and Reinstatement in a Passive Avoidance Paradigm. Percept Mot Skills 2016; 123:5-16. [PMID: 27307156 DOI: 10.1177/0031512516654464] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Recent research suggests that extinction occurring shortly after fear conditioning attenuates spontaneous recovery and reinstatement of fear. Two experiments investigated whether immediate extinction would prevent spontaneous recovery and reinstatement of fear using a passive avoidance paradigm. In Experiment 1, naive female adult rats (N = 40) received extinction training either immediately or 24 hours (delayed) after fear conditioning. Both extinction groups showed a significant reduction in fear at a 1-day test. At a 15-day test, spontaneous recovery was observed in the delayed extinction group while the immediate extinction group continued to show significant extinction. In Experiment 2, using a naive group of adult female rats (N = 16), the extinction result was replicated in both the immediate and delayed extinction groups at the 1-day interval. Reinstatement of fear, elicited by foot-shock in a neutral environment, was observed for the delayed group but not for the immediate group. By utilizing the passive-avoidance paradigm, these experiments replicate and extend previous findings that immediate extinction attenuates spontaneous recovery and reinstatement of fear.
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Affiliation(s)
- James F Briggs
- Department of Psychology, Susquehanna University, Selinsgrove, PA, USA
| | - Devin A Fava
- Department of Psychological Science, Saint Vincent College, Latrobe, PA, USA
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9
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Baratta MV, Kodandaramaiah SB, Monahan PE, Yao J, Weber MD, Lin PA, Gisabella B, Petrossian N, Amat J, Kim K, Yang A, Forest CR, Boyden ES, Goosens KA. Stress Enables Reinforcement-Elicited Serotonergic Consolidation of Fear Memory. Biol Psychiatry 2016; 79:814-822. [PMID: 26248536 PMCID: PMC4698247 DOI: 10.1016/j.biopsych.2015.06.025] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 06/02/2015] [Accepted: 06/17/2015] [Indexed: 01/03/2023]
Abstract
BACKGROUND Prior exposure to stress is a risk factor for developing posttraumatic stress disorder (PTSD) in response to trauma, yet the mechanisms by which this occurs are unclear. Using a rodent model of stress-based susceptibility to PTSD, we investigated the role of serotonin in this phenomenon. METHODS Adult mice were exposed to repeated immobilization stress or handling, and the role of serotonin in subsequent fear learning was assessed using pharmacologic manipulation and western blot detection of serotonin receptors, measurements of serotonin, high-speed optogenetic silencing, and behavior. RESULTS Both dorsal raphe serotonergic activity during aversive reinforcement and amygdala serotonin 2C receptor (5-HT2CR) activity during memory consolidation were necessary for stress enhancement of fear memory, but neither process affected fear memory in unstressed mice. Additionally, prior stress increased amygdala sensitivity to serotonin by promoting surface expression of 5-HT2CR without affecting tissue levels of serotonin in the amygdala. We also showed that the serotonin that drives stress enhancement of associative cued fear memory can arise from paired or unpaired footshock, an effect not predicted by theoretical models of associative learning. CONCLUSIONS Stress bolsters the consequences of aversive reinforcement, not by simply enhancing the neurobiological signals used to encode fear in unstressed animals, but rather by engaging distinct mechanistic pathways. These results reveal that predictions from classical associative learning models do not always hold for stressed animals and suggest that 5-HT2CR blockade may represent a promising therapeutic target for psychiatric disorders characterized by excessive fear responses such as that observed in PTSD.
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MESH Headings
- Amygdala/drug effects
- Amygdala/metabolism
- Animals
- Association Learning/drug effects
- Association Learning/physiology
- Conditioning, Psychological/drug effects
- Conditioning, Psychological/physiology
- Disease Models, Animal
- Dorsal Raphe Nucleus/metabolism
- Electroshock
- Fear/drug effects
- Fear/physiology
- Male
- Memory Consolidation/drug effects
- Memory Consolidation/physiology
- Mice, Inbred C57BL
- Mice, Transgenic
- Models, Neurological
- Models, Psychological
- Neurons/drug effects
- Neurons/metabolism
- Optogenetics
- Receptor, Serotonin, 5-HT2C/metabolism
- Restraint, Physical
- Serotonin/metabolism
- Serotonin 5-HT2 Receptor Antagonists/pharmacology
- Serotonin Plasma Membrane Transport Proteins/genetics
- Serotonin Plasma Membrane Transport Proteins/metabolism
- Stress Disorders, Post-Traumatic/metabolism
- Stress, Psychological/physiopathology
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Affiliation(s)
- Michael V Baratta
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, Massachusetts; MIT Media Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Suhasa B Kodandaramaiah
- MIT Media Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts; The George W. Woodruff School of Mechanical Engineering (SBK, CRF), Georgia Institute of Technology, Atlanta, Georgia
| | - Patrick E Monahan
- MIT Media Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Junmei Yao
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, Massachusetts; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Michael D Weber
- Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, Colorado
| | - Pei-Ann Lin
- MIT Media Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Barbara Gisabella
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, Massachusetts; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Natalie Petrossian
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, Massachusetts; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Jose Amat
- Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, Colorado
| | - Kyungman Kim
- MIT Media Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Aimei Yang
- MIT Media Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Craig R Forest
- The George W. Woodruff School of Mechanical Engineering (SBK, CRF), Georgia Institute of Technology, Atlanta, Georgia
| | - Edward S Boyden
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, Massachusetts; MIT Media Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Ki A Goosens
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, Massachusetts.
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10
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Bernier BE, Lacagnina AF, Drew MR. Potent attenuation of context fear by extinction training contiguous with acquisition. ACTA ACUST UNITED AC 2014; 22:31-8. [PMID: 25512575 PMCID: PMC4274325 DOI: 10.1101/lm.036673.114] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Studies on the behavioral mechanisms underlying contextual fear conditioning (CFC) have demonstrated the importance of preshock context exposure in the formation of aversive context memories. However, there has been comparatively little investigation of the effects of context exposure immediately after the shock. Some models predict that nonreinforced context exposure at the end of the acquisition session will strongly influence the strength of conditioning and/or recruit distinct neural mechanisms relative to extinction after acquisition. Here we investigate the effects of manipulating postshock context exposure on CFC in mice. Prolonging the period of context exposure immediately following the shock caused a significant and durable reduction in conditioned fear. This immediate postshock context exposure was more effective at attenuating conditioned fear than was an equivalent amount of context exposure a day or more after acquisition. The results suggest that nonreinforced exposure to the context influences conditioned fear through distinct mechanisms depending on whether it occurs during acquisition or after it. The superiority of immediate postshock context exposure was specific to single-shock CFC; in two-shock CFC, immediate and delayed postshock context exposure had similar effects. Consistent with previous reports, we hypothesize that the effectiveness of extinction is modulated by emotional state, and procedures engendering higher postshock freezing (such as two-shock CFC) are associated with weaker immediate extinction.
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Affiliation(s)
- Brian E Bernier
- Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, Texas, 78712, USA
| | - Anthony F Lacagnina
- Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, Texas, 78712, USA
| | - Michael R Drew
- Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, Texas, 78712, USA
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11
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Haaker J, Golkar A, Hermans D, Lonsdorf TB. A review on human reinstatement studies: an overview and methodological challenges. Learn Mem 2014; 21:424-40. [PMID: 25128533 PMCID: PMC4138360 DOI: 10.1101/lm.036053.114] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Accepted: 06/17/2014] [Indexed: 12/19/2022]
Abstract
In human research, studies of return of fear (ROF) phenomena, and reinstatement in particular, began only a decade ago and recently are more widely used, e.g., as outcome measures for fear/extinction memory manipulations (e.g., reconsolidation). As reinstatement research in humans is still in its infancy, providing an overview of its stability and boundary conditions and summarizing methodological challenges is timely to foster fruitful future research. As a translational endeavor, clarifying the circumstances under which (experimental) reinstatement occurs may offer a first step toward understanding relapse as a clinical phenomenon and pave the way for the development of new pharmacological or behavioral ways to prevent ROF. The current state of research does not yet allow pinpointing these circumstances in detail and we hope this review will aid the research field to advance in this direction. As an introduction, we begin with a synopsis of rodent work on reinstatement and theories that have been proposed to explain the findings. The review however mainly focuses on reinstatement in humans. We first describe details and variations of the experimental setup in reinstatement studies in humans and give a general overview of results. We continue with a compilation of possible experimental boundary conditions and end with the role of individual differences and behavioral and/or pharmacological manipulations. Furthermore, we compile important methodological and design details on the published studies in humans and end with open research questions and some important methodological and design recommendations as a guide for future research.
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Affiliation(s)
- Jan Haaker
- Institute for Systems Neuroscience, University Hospital Hamburg-Eppendorf, 20246 Hamburg, Germany Karolinska Institute, Department of Clinical Neuroscience, 171 77 Stockholm, Sweden
| | - Armita Golkar
- Karolinska Institute, Department of Clinical Neuroscience, 171 77 Stockholm, Sweden
| | - Dirk Hermans
- Faculty of Psychology and Educational Sciences, University of Leuven, 3000 Leuven, Belgium
| | - Tina B Lonsdorf
- Institute for Systems Neuroscience, University Hospital Hamburg-Eppendorf, 20246 Hamburg, Germany
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12
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Hofmann F, Flockerzi V, Kahl S, Wegener JW. L-type CaV1.2 calcium channels: from in vitro findings to in vivo function. Physiol Rev 2014; 94:303-26. [PMID: 24382889 DOI: 10.1152/physrev.00016.2013] [Citation(s) in RCA: 239] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The L-type Cav1.2 calcium channel is present throughout the animal kingdom and is essential for some aspects of CNS function, cardiac and smooth muscle contractility, neuroendocrine regulation, and multiple other processes. The L-type CaV1.2 channel is built by up to four subunits; all subunits exist in various splice variants that potentially affect the biophysical and biological functions of the channel. Many of the CaV1.2 channel properties have been analyzed in heterologous expression systems including regulation of the L-type CaV1.2 channel by Ca(2+) itself and protein kinases. However, targeted mutations of the calcium channel genes confirmed only some of these in vitro findings. Substitution of the respective serines by alanine showed that β-adrenergic upregulation of the cardiac CaV1.2 channel did not depend on the phosphorylation of the in vitro specified amino acids. Moreover, well-established in vitro phosphorylation sites of the CaVβ2 subunit of the cardiac L-type CaV1.2 channel were found to be irrelevant for the in vivo regulation of the channel. However, the molecular basis of some kinetic properties, such as Ca(2+)-dependent inactivation and facilitation, has been approved by in vivo mutagenesis of the CaV1.2α1 gene. This article summarizes recent findings on the in vivo relevance of well-established in vitro results.
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Sears RM, Schiff HC, LeDoux JE. Molecular Mechanisms of Threat Learning in the Lateral Nucleus of the Amygdala. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 122:263-304. [DOI: 10.1016/b978-0-12-420170-5.00010-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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14
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Baker KD, Edwards TM, Rickard NS. The role of intracellular calcium stores in synaptic plasticity and memory consolidation. Neurosci Biobehav Rev 2013; 37:1211-39. [PMID: 23639769 DOI: 10.1016/j.neubiorev.2013.04.011] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 04/18/2013] [Accepted: 04/22/2013] [Indexed: 12/20/2022]
Abstract
Memory processing requires tightly controlled signalling cascades, many of which are dependent upon intracellular calcium (Ca(2+)). Despite this, most work investigating calcium signalling in memory formation has focused on plasma membrane channels and extracellular sources of Ca(2+). The intracellular Ca(2+) release channels, ryanodine receptors (RyRs) and inositol (1,4,5)-trisphosphate receptors (IP3Rs) have a significant capacity to regulate intracellular Ca(2+) signalling. Evidence at both cellular and behavioural levels implicates both RyRs and IP3Rs in synaptic plasticity and memory formation. Pharmacobehavioural experiments using young chicks trained on a single-trial discrimination avoidance task have been particularly useful by demonstrating that RyRs and IP3Rs have distinct roles in memory formation. RyR-dependent Ca(2+) release appears to aid the consolidation of labile memory into a persistent long-term memory trace. In contrast, IP3Rs are required during long-term memory. This review discusses various functions for RyRs and IP3Rs in memory processing, including neuro- and glio-transmitter release, dendritic spine remodelling, facilitating vasodilation, and the regulation of gene transcription and dendritic excitability. Altered Ca(2+) release from intracellular stores also has significant implications for neurodegenerative conditions.
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Affiliation(s)
- Kathryn D Baker
- School of Psychology and Psychiatry, Monash University, Clayton 3800, Victoria, Australia.
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Early intervention may prevent the development of posttraumatic stress disorder: a randomized pilot civilian study with modified prolonged exposure. Biol Psychiatry 2012; 72:957-63. [PMID: 22766415 PMCID: PMC3467345 DOI: 10.1016/j.biopsych.2012.06.002] [Citation(s) in RCA: 174] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 06/01/2012] [Accepted: 06/05/2012] [Indexed: 12/14/2022]
Abstract
BACKGROUND Posttraumatic stress disorder (PTSD) is a major public health concern with long-term sequelae. There are no accepted interventions delivered in the immediate aftermath of trauma. This study tested an early intervention aimed at modifying the memory to prevent the development of PTSD before memory consolidation. METHODS Patients (n = 137) were randomly assigned to receive three sessions of an early intervention beginning in the emergency department compared with an assessment only control group. Posttraumatic stress reactions (PTSR) were assessed at 4 and 12 weeks postinjury and depression at baseline and week 4. The intervention consisted of modified prolonged exposure including imaginal exposure to the trauma memory, processing of traumatic material, and in vivo and imaginal exposure homework. RESULTS Patients were assessed an average of 11.79 hours posttrauma. Intervention participants reported significantly lower PTSR than the assessment group at 4 weeks postinjury, p < .01, and at 12 weeks postinjury, p < .05, and significantly lower depressive symptoms at week 4 than the assessment group, p < .05. In a subgroup analysis, the intervention was the most effective at reducing PTSD in rape victims at week 4 (p = .004) and week 12 (p = .05). CONCLUSIONS These findings suggest that the modified prolonged exposure intervention initiated within hours of the trauma in the emergency department is successful at reducing PTSR and depression symptoms 1 and 3 months after trauma exposure and is safe and feasible. This is the first behavioral intervention delivered immediately posttrauma that has been shown to be effective at reducing PTSR.
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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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Kearns MC, Ressler KJ, Zatzick D, Rothbaum BO. Early interventions for PTSD: a review. Depress Anxiety 2012; 29:833-42. [PMID: 22941845 PMCID: PMC3665083 DOI: 10.1002/da.21997] [Citation(s) in RCA: 177] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 06/05/2012] [Accepted: 08/03/2012] [Indexed: 11/10/2022] Open
Abstract
The high prevalence of trauma exposure and subsequent negative consequences for both survivors and society as a whole emphasize the need for secondary prevention of posttraumatic stress disorder. However, clinicians and relief workers remain limited in their ability to intervene effectively in the aftermath of trauma and alleviate traumatic stress reactions that can lead to chronic PTSD. The scientific literature on early intervention for PTSD is reviewed, including early studies on psychological debriefing, pharmacological, and psychosocial interventions aimed at preventing chronic PTSD. Studies on fear extinction and memory consolidation are discussed in relation to PTSD prevention and the potential importance of immediate versus delayed intervention approaches and genetic predictors are briefly reviewed. Preliminary results from a modified prolonged exposure intervention applied within hours of trauma exposure in an emergency room setting are discussed, along with considerations related to intervention reach and overall population impact. Suggestions for future research are included. Prevention of PTSD, although currently not yet a reality, remains an exciting and hopeful possibility with current research approaches translating work from the laboratory to the clinic.
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Affiliation(s)
| | | | - Doug Zatzick
- University of Washington School of Medicine, Seattle, Washington
| | - Barbara Olasov Rothbaum
- Emory University School of Medicine, Atlanta, Georgia,Correspondence to: Barbara Olasov Rothbaum, Ph.D., A.B.P.P., Emory University School of Medicine, 1256 Briarcliff Road, Atlanta, GA 30306.
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Orsini CA, Maren S. Neural and cellular mechanisms of fear and extinction memory formation. Neurosci Biobehav Rev 2012; 36:1773-802. [PMID: 22230704 PMCID: PMC3345303 DOI: 10.1016/j.neubiorev.2011.12.014] [Citation(s) in RCA: 321] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2011] [Revised: 12/16/2011] [Accepted: 12/23/2011] [Indexed: 02/08/2023]
Abstract
Over the course of natural history, countless animal species have evolved adaptive behavioral systems to cope with dangerous situations and promote survival. Emotional memories are central to these defense systems because they are rapidly acquired and prepare organisms for future threat. Unfortunately, the persistence and intrusion of memories of fearful experiences are quite common and can lead to pathogenic conditions, such as anxiety and phobias. Over the course of the last 30 years, neuroscientists and psychologists alike have attempted to understand the mechanisms by which the brain encodes and maintains these aversive memories. Of equal interest, though, is the neurobiology of extinction memory formation as this may shape current therapeutic techniques. Here we review the extant literature on the neurobiology of fear and extinction memory formation, with a strong focus on the cellular and molecular mechanisms underlying these processes.
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Affiliation(s)
- Caitlin A. Orsini
- Department of Psychology, University of Michigan, Ann Arbor, MI, 48109-1043, USA
| | - Stephen Maren
- Department of Psychology, University of Michigan, Ann Arbor, MI, 48109-1043, USA
- Department of Neuroscience Program, University of Michigan, Ann Arbor, MI, 48109-1043, USA
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The role of metaplasticity mechanisms in regulating memory destabilization and reconsolidation. Neurosci Biobehav Rev 2012; 36:1667-707. [PMID: 22484475 DOI: 10.1016/j.neubiorev.2012.03.008] [Citation(s) in RCA: 144] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 03/09/2012] [Accepted: 03/21/2012] [Indexed: 12/13/2022]
Abstract
Memory allows organisms to predict future events based on prior experiences. This requires encoded information to persist once important predictors are extracted, while also being modifiable in response to changes within the environment. Memory reconsolidation may allow stored information to be modified in response to related experience. However, there are many boundary conditions beyond which reconsolidation may not occur. One interpretation of these findings is that the event triggering memory retrieval must contain new information about a familiar stimulus in order to induce reconsolidation. Presently, the mechanisms that affect the likelihood of reconsolidation occurring under these conditions are not well understood. Here we speculate on a number of systems that may play a role in protecting memory from being destabilized during retrieval. We conclude that few memories may enter a state in which they cannot be modified. Rather, metaplasticity mechanisms may serve to alter the specific reactivation cues necessary to destabilize a memory. This might imply that destabilization mechanisms can differ depending on learning conditions.
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20
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Davis M. NMDA receptors and fear extinction: implications for cognitive behavioral therapy. DIALOGUES IN CLINICAL NEUROSCIENCE 2012. [PMID: 22275851 PMCID: PMC3263393 DOI: 10.31887/dcns.2011.13.4/mdavis] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Based primarily on studies that employ Pavlovian fear conditioning, extinction of conditioned fear has been found to be mediated by N-methyl-D-aspartate (NMDA) receptors in the amygdala and medial prefrontal cortex. This led to the discovery that an NMDA partial agonist, D-cycloserine, could facilitate fear extinction when given systemically or locally into the amygdala. Because many forms of cognitive behavioral therapy depend on fear extinction, this led to the successful use of D-cycloserine as an adjunct to psychotherapy in patients with so-called simple phobias (fear of heights), social phobia, obsessive-compulsive behavior, and panic disorder. Data in support of these conclusions are reviewed, along with some of the possible limitations of D-cycloserine as an adjunct to psychotherapy.
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Affiliation(s)
- Michael Davis
- Emory University, Yerkes National Primate Center and the Center for Behavioral Neuroscience, Atlanta, Georgia, USA.
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21
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Tronson NC, Corcoran KA, Jovasevic V, Radulovic J. Fear conditioning and extinction: emotional states encoded by distinct signaling pathways. Trends Neurosci 2011; 35:145-55. [PMID: 22118930 DOI: 10.1016/j.tins.2011.10.003] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Revised: 07/29/2011] [Accepted: 10/21/2011] [Indexed: 10/15/2022]
Abstract
Conditioning and extinction of fear have traditionally been viewed as two independent learning processes for encoding representations of contexts or cues (conditioned stimuli, CS), aversive events (unconditioned stimuli, US), and their relationship. Based on the analysis of protein kinase signaling patterns in neurons of the fear circuit, we propose that fear and extinction are best conceptualized as emotional states triggered by a single CS representation with two opposing values: aversive and non-aversive. These values are conferred by the presence or absence of the US and encoded by distinct sets of kinase signaling pathways and their downstream targets. Modulating specific protein kinases thus has the potential to modify emotional states, and hence, may emerge as a promising treatment for anxiety disorders.
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Affiliation(s)
- Natalie C Tronson
- Department of Psychiatry and Behavioral Sciences, The Asher Center for Study and Treatment of Depressive Disorders, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
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22
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Hong I, Kim J, Song B, Park S, Lee J, Kim J, An B, Lee S, Choi S. Modulation of fear memory by retrieval and extinction: a clue for memory deconsolidation. Rev Neurosci 2011; 22:205-29. [PMID: 21476941 DOI: 10.1515/rns.2011.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Memories are fragile and easily forgotten at first, but after a consolidation period of hours to weeks, are inscribed in our brains as stable traces, no longer vulnerable to conventional amnesic treatments. Retrieval of a memory renders it labile, akin to the early stages of consolidation. This phenomenon has been explored as memory reactivation, in the sense that the memory is temporarily 'deconsolidated', allowing a short time window for amnesic intervention. This window closes again after reconsolidation, which restores the stability of the memory. In contrast to this 'transient deconsolidation' and the short-spanned amnesic effects of consolidation blockers, some specific treatments can disrupt even consolidated memory, leading to apparent amnesia. We propose the term 'amnesic deconsolidation' to describe such processes that lead to disruption of consolidated memory and/or consolidated memory traces. We review studies of these 'amnesic deconsolidation' treatments that enhance memory extinction, alleviate relapse, and reverse learning-induced plasticity. The transient deconsolidation that memory retrieval induces and the amnesic deconsolidation that these regimes induce both seem to dislodge a component that stabilizes consolidated memory. Characterizing this component, at both molecular and network levels, will provide a key to developing clinical treatments for memory-related disorders and to defining the consolidated memory trace.
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Affiliation(s)
- Ingie Hong
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 151-742, Republic of Korea
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23
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Parkes SL, Westbrook RF. Role of the basolateral amygdala and NMDA receptors in higher-order conditioned fear. Rev Neurosci 2011; 22:317-33. [DOI: 10.1515/rns.2011.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Abstract
Some psychiatric illnesses involve a learned component. For example, in posttraumatic stress disorder, memories triggered by trauma-associated cues trigger fear and anxiety, and in addiction, drug-associated cues elicit drug craving and withdrawal. Clinical interventions to reduce the impact of conditioned cues in eliciting these maladaptive conditioned responses are likely to be beneficial. Extinction is a method of lessening conditioned responses and involves repeated exposures to a cue in the absence of the event it once predicted. We believe that an improved understanding of the behavioral and neurobiological mechanisms of extinction will allow extinction-like procedures in the clinic to become more effective. Research on the role of glutamate-the major excitatory neurotransmitter in the mammalian brain-in extinction has led to the development of pharmacotherapeutics to enhance the efficacy of extinction-based protocols in clinical populations. In this review, we describe what has been learned about glutamate actions at its three major receptor types (N-methyl-D-aspartate (NMDA) receptors, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, and metabotropic glutamate receptors) in the extinction of conditioned fear, drug craving, and withdrawal. We then discuss how these findings have been applied in clinical research.
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25
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Esdin J, Pearce K, Glanzman DL. Long-term habituation of the gill-withdrawal reflex in aplysia requires gene transcription, calcineurin and L-type voltage-gated calcium channels. Front Behav Neurosci 2010; 4:181. [PMID: 21152260 PMCID: PMC2998902 DOI: 10.3389/fnbeh.2010.00181] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Accepted: 11/12/2010] [Indexed: 11/30/2022] Open
Abstract
Although habituation is possibly the simplest form of learning, we still do not fully understand the neurobiological basis of habituation in any organism. To advance the goal of a comprehensive understanding of habituation, we have studied long-term habituation (LTH) of the gill-withdrawal reflex (GWR) in the marine snail Aplysia californica. Previously, we showed that habituation of the GWR in a reduced preparation lasts for up to 12 h, and depends on protein synthesis, as well as activation of protein phosphatases 1 and 2A and postsynaptic glutamate receptors. Here, we have used the reduced preparation to further analyze the mechanisms of LTH in Aplysia. We found that LTH of the GWR depends on RNA synthesis because it was blocked by both the irreversible transcriptional inhibitor actinomycin-D and the reversible transcriptional inhibitor, 5,6-dichlorobenzimidazole riboside (DRB). In addition, LTH requires activation of protein phosphatase 2B (calcineurin), because it was disrupted by ascomycin. Finally, LTH was blocked by nitrendipine, which indicates that activation of l-type voltage-gated Ca2+ channels is required for this form of learning. Together with our previous results, the present results indicate that exclusively presynaptic mechanisms, although possibly sufficient for short-term habituation, are insufficient for LTH. Rather, LTH must involve postsynaptic, as well as presynaptic, mechanisms.
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Affiliation(s)
- Joseph Esdin
- Department of Integrative Biology and Physiology, University of California Los Angeles, CA, USA
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26
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Lin PY, Wang SP, Tai MY, Tsai YF. Differential involvement of medial prefrontal cortex and basolateral amygdala extracellular signal-regulated kinase in extinction of conditioned taste aversion is dependent on different intervals of extinction following conditioning. Neuroscience 2010; 171:125-33. [DOI: 10.1016/j.neuroscience.2010.08.066] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2010] [Revised: 08/30/2010] [Accepted: 08/31/2010] [Indexed: 11/24/2022]
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27
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Langton JM, Richardson R. The effect of D-cycloserine on immediate vs. delayed extinction of learned fear. Learn Mem 2010; 17:547-51. [PMID: 20971937 DOI: 10.1101/lm.1927310] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We compared the effect of D-cycloserine (DCS) on immediate (10 min after conditioning) and delayed (24 h after conditioning) extinction of learned fear in rats. DCS facilitated both immediate and delayed extinction when the drug was administered after extinction training. However, DCS did not facilitate immediate extinction when administered prior to extinction training (i.e., when the interval between drug administration and shock was reduced). In addition, administering five, but not two, shocks prior to extinction training disrupted the facilitating effects of DCS on delayed extinction. These results suggest that aversive experiences prior to DCS administration can prevent it from facilitating extinction.
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Affiliation(s)
- Julia M Langton
- Adult Cancer Program, Prince of Wales Clinical School, University of New South Wales, Sydney 2052, Australia.
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28
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Baldi E, Bucherelli C. Substantia nigra, nucleus basalis magnocellularis and basolateral amygdala roles in extinction of contextual fear conditioning in the rat. Neurobiol Learn Mem 2010; 94:199-205. [DOI: 10.1016/j.nlm.2010.05.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Revised: 05/12/2010] [Accepted: 05/15/2010] [Indexed: 11/16/2022]
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Abstract
Exposure to traumatic events that produce extreme fear and horror is all too common in both military and civilian populations, but not all individuals develop posttraumatic stress disorder (PTSD) as a result of the exposure. What mediates risk and resilience in the development of PTSD and other stress-related psychopathology is of paramount importance to our further understanding of trauma-related psychopathology as well as the development of new treatment approaches. Biological factors, such as genotype and neurobiology, interact with environmental factors, such as childhood background and trauma load, to affect vulnerability and resilience in the aftermath of trauma exposure. One of the core symptoms of PTSD is the inability to control fear, which has led some investigators and clinicians to conceptualize PTSD as a disorder of fear or, more importantly, its inhibition. This review focuses on translational methods that have been used to examine fear conditioning and inhibition of fear in PTSD and summarizes genetic and neurobiological factors related to fear inhibition. The authors also discuss different pharmacological approaches that enhance fear inhibition and may improve treatment outcomes for patients with PTSD.
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30
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Pape HC, Pare D. Plastic synaptic networks of the amygdala for the acquisition, expression, and extinction of conditioned fear. Physiol Rev 2010; 90:419-63. [PMID: 20393190 DOI: 10.1152/physrev.00037.2009] [Citation(s) in RCA: 756] [Impact Index Per Article: 54.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The last 10 years have witnessed a surge of interest for the mechanisms underlying the acquisition and extinction of classically conditioned fear responses. In part, this results from the realization that abnormalities in fear learning mechanisms likely participate in the development and/or maintenance of human anxiety disorders. The simplicity and robustness of this learning paradigm, coupled with the fact that the underlying circuitry is evolutionarily well conserved, make it an ideal model to study the basic biology of memory and identify genetic factors and neuronal systems that regulate the normal and pathological expressions of learned fear. Critical advances have been made in determining how modified neuronal functions upon fear acquisition become stabilized during fear memory consolidation and how these processes are controlled in the course of fear memory extinction. With these advances came the realization that activity in remote neuronal networks must be coordinated for these events to take place. In this paper, we review these mechanisms of coordinated network activity and the molecular cascades leading to enduring fear memory, and allowing for their extinction. We will focus on Pavlovian fear conditioning as a model and the amygdala as a key component for the acquisition and extinction of fear responses.
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Affiliation(s)
- Hans-Christian Pape
- Institute of Physiology, Westfaelische Wilhelms-University, Muenster, Germany; and Rutgers State University, Newark, New Jersey, USA.
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31
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Archbold GEB, Bouton ME, Nader K. Evidence for the persistence of contextual fear memories following immediate extinction. Eur J Neurosci 2010; 31:1303-11. [PMID: 20345921 DOI: 10.1111/j.1460-9568.2010.07161.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Evidence suggests that extinction, the suppression of a learned response to a Pavlovian signal that is produced by exposure to the signal alone after conditioning, is a consequence of new inhibitory learning. However, it has been proposed that extinction given immediately after conditioning reflects memory 'erasure'. Using contextual fear conditioning, we examine the nature of extinction further using a novel behavioral paradigm that probes for the absence or presence of a memory. Rats received a context paired with one of three different shock intensities (0.8, 1.2 or 1.6 mA) and then received extinction either immediately (15 min) or after a delay (24 h). Spontaneous recovery was roughly equivalent in the immediate and delayed extinction groups when they were tested at 24 h after extinction. To further test the status of the original memory trace, we exploited the effect that only the first, but not second, learning of contextual fear requires N-methyl-D-aspartate receptors (NMDArs) in the dorsal hippocampus [M.J. Sanders & M.S. Fanselow (2003) Neurobiology of Learning and Memory 80,123-129]. Here we use this property of second learning to determine if memory of an immediately extinguished fear also persists. Rats received bilateral infusions of the NMDAr antagonist DL-2-amino-5-phosphonopentanoic acid into the dorsal hippocampus prior to training in a novel second context. Memory for the second learning is not affected by NMDAr blockade in either group, suggesting that the extinguished memory is not erased but inhibited. Overall, the results provide little evidence that extinction conducted immediately after conditioning destroys or erases the original memory trace.
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Affiliation(s)
- Georgina E B Archbold
- Department of Psychology, McGill University, 1205 Dr Penfield Avenue, Montreal, QC, Canada H3A 1B1.
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32
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Huff NC, Hernandez JA, Blanding NQ, LaBar KS. Delayed extinction attenuates conditioned fear renewal and spontaneous recovery in humans. Behav Neurosci 2009; 123:834-43. [PMID: 19634943 DOI: 10.1037/a0016511] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This study investigated whether the retention interval after an aversive learning experience influences the return of fear after extinction training. After fear conditioning, participants underwent extinction training either 5 min or 1 day later and in either the same room (same context) or a different room (context shift). The next day, conditioned fear was tested in the original room. When extinction took place immediately, fear renewal was robust and prolonged for context-shift participants, and spontaneous recovery was observed in the same-context participants. Delayed extinction, by contrast, yielded a brief form of fear renewal that reextinguished within the testing session for context-shift participants, and there was no spontaneous recovery in the same-context participants. The authors conclude that the passage of time allows for memory consolidation processes to promote the formation of distinct yet flexible emotional memory traces that confer an ability to recall extinction, even in an alternate context, and minimize the return of fear. Furthermore, immediate extinction can yield spontaneous recovery and prolong fear renewal. These findings have potential implications for ameliorating fear relapse in anxiety disorders.
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Affiliation(s)
- Nicole C Huff
- Center for Cognitive Neuroscience, Duke University, Durham, NC 27708, USA
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Norrholm SD, Vervliet B, Jovanovic T, Boshoven W, Myers KM, Davis M, Rothbaum B, Duncan EJ. Timing of extinction relative to acquisition: a parametric analysis of fear extinction in humans. Behav Neurosci 2009; 122:1016-30. [PMID: 18823159 DOI: 10.1037/a0012604] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Fear extinction is a reduction in conditioned fear following repeated exposure to the feared cue in the absence of any aversive event. Extinguished fear often reappears after extinction through spontaneous recovery. Animal studies suggest that spontaneous recovery can be abolished if extinction occurs within minutes of acquisition. However, a limited number of human extinction studies have shown that short interval extinction does not prevent the return of fear. For this reason, we performed an in-depth parametric analysis of human fear extinction using fear-potentiated startle. Using separate single-cue and differential conditioning paradigms, participants were fear conditioned and then underwent extinction either 10 min (Immediate) or 72 hr (Delayed) later. Testing for spontaneous recovery occurred 96 hr after acquisition. In the single cue paradigm, the Immediate and Delayed groups exhibited differences in context, but not fear, conditioning. With differential conditioning, there were no differences in context conditioning and the Immediate group displayed less spontaneous recovery. Thus, the results remain inconclusive regarding spontaneous recovery and the timing of extinction and are discussed in terms of performing translational studies of fear in humans.
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Affiliation(s)
- Seth D Norrholm
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA.
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Kimura R, Silva AJ, Ohno M. Autophosphorylation of alphaCaMKII is differentially involved in new learning and unlearning mechanisms of memory extinction. Learn Mem 2008; 15:837-43. [PMID: 18984565 DOI: 10.1101/lm.1049608] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Accumulating evidence indicates the key role of alpha-calcium/calmodulin-dependent protein kinase II (alphaCaMKII) in synaptic plasticity and learning, but it remains unclear how this kinase participates in the processing of memory extinction. Here, we investigated the mechanism by which alphaCaMKII may mediate extinction by using heterozygous knock-in mice with a targeted T286A mutation that prevents the autophosphorylation of this kinase (alphaCaMKII(T286A+/-)). Remarkably, partial reduction of alphaCaMKII function due to the T286A(+/-) mutation prevented the development of extinction without interfering with initial hippocampus-dependent memory formation as assessed by contextual fear conditioning and the Morris water maze. It is hypothesized that the mechanism of extinction may differ depending on the interval at which extinction training is started, being more akin to "new learning" at longer intervals and "unlearning" or "erasure" at shorter intervals. Consistent with this hypothesis, we found that extinction conducted 24 h, but not 15 min, after contextual fear training showed spontaneous recovery (reappearance of extinguished freezing responses) 21 d following the extinction, representing behavioral evidence for new learning and unlearning mechanisms underlying extinction 24 h and 15 min post-training, respectively. Importantly, the alphaCaMKII(T286A+/-) mutation blocked new learning of contextual fear memory extinction, whereas it did not interfere with unlearning processes. Our results demonstrate a genetic dissociation of new learning and unlearning mechanisms of extinction, and suggest that alphaCaMKII is responsible for extinguishing memories specifically through new learning mechanisms.
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Affiliation(s)
- Ryoichi Kimura
- Center for Dementia Research, Nathan Kline Institute, New York University School of Medicine, Orangeburg, New York 10962, USA
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35
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Abstract
Fear responses can be eliminated through extinction, a procedure involving the presentation of fear-eliciting stimuli without aversive outcomes. Extinction is believed to be mediated by new inhibitory learning that acts to suppress fear expression without erasing the original memory trace. This hypothesis is supported mainly by behavioral data demonstrating that fear can recover following extinction. However, a recent report by Myers and coworkers suggests that extinction conducted immediately after fear learning may erase or prevent the consolidation of the fear memory trace. Since extinction is a major component of nearly all behavioral therapies for human fear disorders, this finding supports the notion that therapeutic intervention beginning very soon after a traumatic event will be more efficacious. Given the importance of this issue, and the controversy regarding immediate versus delayed therapeutic interventions, we examined two fear recovery phenomena in both rats and humans: spontaneous recovery (SR) and reinstatement. We found evidence for SR and reinstatement in both rats and humans even when extinction was conducted immediately after fear learning. Thus, our data do not support the hypothesis that immediate extinction erases the original memory trace, nor do they suggest that a close temporal proximity of therapeutic intervention to the traumatic event might be advantageous.
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Busquet P, Hetzenauer A, Sinnegger-Brauns MJ, Striessnig J, Singewald N. Role of L-type Ca2+ channel isoforms in the extinction of conditioned fear. Learn Mem 2008; 15:378-86. [PMID: 18441296 PMCID: PMC2364608 DOI: 10.1101/lm.886208] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Accepted: 02/15/2008] [Indexed: 11/24/2022]
Abstract
Dihydropyridine (DHP) L-type Ca(2+) channel (LTCC) antagonists, such as nifedipine, have been reported to impair the extinction of conditioned fear without interfering with its acquisition. Identification of the LTCC isoforms mediating this DHP effect is an essential basis to reveal their role as potential drug targets for the treatment of specific anxiety disorders. Ca(V)1.2 and Ca(V)1.3 are the predominant LTCCs in the mammalian brain. However, since no isoform-selective DHP blockers are available, their individual contribution to fear memory extinction is unknown. We used a novel mouse model expressing DHP-insensitive Ca(V)1.2 LTCCs (Ca(V)1.2DHP(-/-) mice) to address this question. In line with previous studies, wild-type (WT) mice treated with systemic nifedipine displayed markedly impaired fear extinction. This DHP effect was completely abolished in Ca(V)1.2DHP(-/-) mice, indicating that it is mediated by Ca(V)1.2, but not by Ca(V)1.3 LTCCs. Supporting this conclusion, Ca(V)1.3-deficient mice (Ca(V)1.3(-/-)) showed extinction identical to the respective WT mice. The inhibition of fear extinction was not observed after intracerebroventricular (i.c.v.) application of different doses of nifedipine, suggesting that this effect is secondary to inhibition of peripheral Ca(V)1.2 channels. The LTCC activator BayK, which lacks neurotoxic effects in Ca(V)1.2DHP(-/-) mice, did not influence the extinction time course. In summary, we demonstrate that LTCC signaling through the Ca(V)1.2 isoform of LTCCs interferes with fear memory extinction, presumably via a peripherally mediated mechanism. Activation of other LTCC isoforms (predominantly Ca(V)1.3) is not sufficient to accelerate extinction of conditioned fear in mice.
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Affiliation(s)
- Perrine Busquet
- Department of Pharmacology and Toxicology, Institute of Pharmacy and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, A-6020 Innsbruck, Austria
| | - Alfred Hetzenauer
- Department of Pharmacology and Toxicology, Institute of Pharmacy and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, A-6020 Innsbruck, Austria
| | - Martina J. Sinnegger-Brauns
- Department of Pharmacology and Toxicology, Institute of Pharmacy and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, A-6020 Innsbruck, Austria
| | - Jörg Striessnig
- Department of Pharmacology and Toxicology, Institute of Pharmacy and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, A-6020 Innsbruck, Austria
| | - Nicolas Singewald
- Department of Pharmacology and Toxicology, Institute of Pharmacy and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, A-6020 Innsbruck, Austria
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McKinney BC, Sze W, White JA, Murphy GG. L-type voltage-gated calcium channels in conditioned fear: a genetic and pharmacological analysis. Learn Mem 2008; 15:326-34. [PMID: 18441291 DOI: 10.1101/lm.893808] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Using pharmacological approaches, others have suggested that L-type voltage-gated calcium channels (L-VGCCs) mediate both consolidation and extinction of conditioned fear. In the absence of L-VGCC isoform-specific antagonists, we have begun to investigate the subtype-specific role of LVGCCs in consolidation and extinction of conditioned fear using a molecular genetics approach. Previously, we used this approach to demonstrate that the Ca(v)1.3 isoform mediates consolidation, but not extinction, of contextually conditioned fear. Here, we used mice in which the gene for the L-VGCC pore-forming subunit Ca(v)1.2 was conditionally deleted in forebrain excitatory neurons (Ca(v)1.2(cKO) mice) to address the role of Ca(v)1.2 in consolidation and extinction of conditioned fear. We demonstrate that Ca(v)1.2(cKO) mice consolidate and extinguish conditioned fear as well as control littermates. These data suggest that Ca(v)1.2 is not critical for these processes and together with our previous data argue against a role for either of the brain-expressed L-VGCCs (Ca(v)1.2 or Ca(v)1.3) in extinction of conditioned fear. Additionally, we present data demonstrating that the L-VGCC antagonist nifedipine, which has been used in previous conditioned fear extinction studies, impairs locomotion, and induces an aversive state. We further demonstrate that this aversive state can enter into associations with conditioned stimuli that are present at the time that it is experienced, suggesting that previous studies using nifedipine were likely confounded by drug toxicity. Taken together, our genetic and pharmacological data argue against a role for Ca(v)1.2 in consolidation of conditioned fear as well as a role for L-VGCCs in extinction of conditioned fear.
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Affiliation(s)
- Brandon C McKinney
- Medical Scientist Training Program, University of Michigan, Ann Arbor, Michigan 48109, USA
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38
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Schafe GE. Rethinking the role of L-type voltage-gated calcium channels in fear memory extinction. Learn Mem 2008; 15:324-5. [DOI: 10.1101/lm.996908] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Craske MG, Kircanski K, Zelikowsky M, Mystkowski J, Chowdhury N, Baker A. Optimizing inhibitory learning during exposure therapy. Behav Res Ther 2008; 46:5-27. [PMID: 18005936 DOI: 10.1016/j.brat.2007.10.003] [Citation(s) in RCA: 888] [Impact Index Per Article: 55.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2007] [Revised: 09/29/2007] [Accepted: 10/02/2007] [Indexed: 11/25/2022]
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Kim J, Lee S, Park K, Hong I, Song B, Son G, Park H, Kim WR, Park E, Choe HK, Kim H, Lee C, Sun W, Kim K, Shin KS, Choi S. Amygdala depotentiation and fear extinction. Proc Natl Acad Sci U S A 2007; 104:20955-60. [PMID: 18165656 PMCID: PMC2409248 DOI: 10.1073/pnas.0710548105] [Citation(s) in RCA: 200] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2007] [Indexed: 11/18/2022] Open
Abstract
Auditory fear memory is thought to be maintained by fear conditioning-induced potentiation of synaptic efficacy, which involves enhanced expression of surface AMPA receptor (AMPAR) at excitatory synapses in the lateral amygdala (LA). Depotentiation, reversal of conditioning-induced potentiation, has been proposed as a cellular mechanism for fear extinction; however, a direct link between depotentiation and extinction has not yet been tested. To address this issue, we applied both ex vivo and in vivo approaches to rats in which fear memory had been consolidated. A unique form of depotentiation reversed conditioning-induced potentiation at thalamic input synapses onto the LA (T-LA synapses) ex vivo. Extinction returned the enhanced T-LA synaptic efficacy observed in conditioned rats to baseline and occluded the depotentiation. Consistently, extinction reversed conditioning-induced enhancement of surface expression of AMPAR subunits in LA synaptosomal preparations. A GluR2-derived peptide that blocks regulated AMPAR endocytosis inhibited depotentiation, and microinjection of a cell-permeable form of the peptide into the LA attenuated extinction. Our results are consistent with the use of depotentiation to weaken potentiated synaptic inputs onto the LA during extinction and provide strong evidence that AMPAR removal at excitatory synapses in the LA underlies extinction.
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Affiliation(s)
- Jeongyeon Kim
- *School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 151-742, Korea
| | - Sukwon Lee
- *School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 151-742, Korea
| | - Kyungjoon Park
- Departments of Biology and Biological and Nanopharmaceutical Sciences, Kyunghee University, Seoul 130-701, Korea
| | - Ingie Hong
- *School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 151-742, Korea
| | - Beomjong Song
- *School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 151-742, Korea
| | - Gihoon Son
- *School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 151-742, Korea
| | - Heewoo Park
- *School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 151-742, Korea
| | - Woon Ryoung Kim
- Department of Anatomy, Division of Brain Korea 21 Biomedical Science, College of Medicine, Korea University, Seoul 136-701, Korea; and
| | - Eunjin Park
- Department of Biological Sciences, College of Natural Sciences, Inha University, 253 Yong-Hyun Dong, Nam-Gu, Inchon 402-751, Korea
| | - Han Kyung Choe
- *School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 151-742, Korea
| | - Hyun Kim
- Department of Anatomy, Division of Brain Korea 21 Biomedical Science, College of Medicine, Korea University, Seoul 136-701, Korea; and
| | - Changjoong Lee
- Department of Biological Sciences, College of Natural Sciences, Inha University, 253 Yong-Hyun Dong, Nam-Gu, Inchon 402-751, Korea
| | - Woong Sun
- Department of Anatomy, Division of Brain Korea 21 Biomedical Science, College of Medicine, Korea University, Seoul 136-701, Korea; and
| | - Kyungjin Kim
- *School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 151-742, Korea
| | - Ki Soon Shin
- Departments of Biology and Biological and Nanopharmaceutical Sciences, Kyunghee University, Seoul 130-701, Korea
| | - Sukwoo Choi
- *School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 151-742, Korea
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41
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Bredy TW, Wu H, Crego C, Zellhoefer J, Sun YE, Barad M. Histone modifications around individual BDNF gene promoters in prefrontal cortex are associated with extinction of conditioned fear. Learn Mem 2007; 14:268-76. [PMID: 17522015 PMCID: PMC2216532 DOI: 10.1101/lm.500907] [Citation(s) in RCA: 418] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Extinction of conditioned fear is an important model both of inhibitory learning and of behavior therapy for human anxiety disorders. Like other forms of learning, extinction learning is long-lasting and depends on regulated gene expression. Epigenetic mechanisms make an important contribution to persistent changes in gene expression; therefore, in these studies, we have investigated whether epigenetic regulation of gene expression contributes to fear extinction. Since brain-derived neurotrophic factor (BDNF) is crucial for synaptic plasticity and for the maintenance of long-term memory, we examined histone modifications around two BDNF gene promoters after extinction of cued fear, as potential targets of learning-induced epigenetic regulation of gene expression. Valproic acid (VPA), used for some time as an anticonvulsant and a mood stabilizer, modulates the expression of BDNF, and is a histone deacetylase (HDAC) inhibitor. Here, we report that extinction of conditioned fear is accompanied by a significant increase in histone H4 acetylation around the BDNF P4 gene promoter and increases in BDNF exon I and IV mRNA expression in prefrontal cortex, that VPA enhances long-term memory for extinction because of its HDAC inhibitor effects, and that VPA potentiates the effect of weak extinction training on histone H4 acetylation around both the BDNF P1 and P4 gene promoters and on BDNF exon IV mRNA expression. These results suggest a relationship between histone H4 modification, epigenetic regulation of BDNF gene expression, and long-term memory for extinction of conditioned fear. In addition, they suggest that HDAC inhibitors may become a useful pharmacological adjunct to psychotherapy for human anxiety disorders.
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Affiliation(s)
- Timothy W. Bredy
- Department of Psychiatry and Biobehavioral Sciences, Brain Research Institute, Semel Institute for Neuroscience and Human Behavior, Los Angeles, California 90095, USA
| | - Hao Wu
- Department of Psychiatry and Biobehavioral Sciences, Brain Research Institute, Semel Institute for Neuroscience and Human Behavior, Los Angeles, California 90095, USA
| | - Cortney Crego
- Department of Psychiatry and Biobehavioral Sciences, Brain Research Institute, Semel Institute for Neuroscience and Human Behavior, Los Angeles, California 90095, USA
| | - Jessica Zellhoefer
- Department of Psychiatry and Biobehavioral Sciences, Brain Research Institute, Semel Institute for Neuroscience and Human Behavior, Los Angeles, California 90095, USA
| | - Yi E. Sun
- Department of Psychiatry and Biobehavioral Sciences, Brain Research Institute, Semel Institute for Neuroscience and Human Behavior, Los Angeles, California 90095, USA
| | - Mark Barad
- Department of Psychiatry and Biobehavioral Sciences, Brain Research Institute, Semel Institute for Neuroscience and Human Behavior, Los Angeles, California 90095, USA
- West Los Angeles VA Medical Center, Los Angeles, California 90073, USA
- Corresponding author.E-mail ; fax (310) 825-9870
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42
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Alvarez RP, Johnson L, Grillon C. Contextual-specificity of short-delay extinction in humans: renewal of fear-potentiated startle in a virtual environment. Learn Mem 2007; 14:247-53. [PMID: 17412963 PMCID: PMC2216529 DOI: 10.1101/lm.493707] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A recent fear-potentiated startle study in rodents suggested that extinction was not context dependent when extinction was conducted after a short delay following acquisition, suggesting that extinction can lead to erasure of fear learning in some circumstances. The main objective of this study was to attempt to replicate these findings in humans by examining the context specificity of short-delay extinction in an ABA renewal procedure using virtual reality environments. A second objective was to examine whether renewal, if any, would be influenced by context conditioning. Subjects underwent differential aversive conditioning in virtual context A, which was immediately followed by extinction in virtual context B. Extinction was followed by tests of renewal in context A and B, with the order counterbalanced across subjects. Results showed that extinction was context dependent. Evidence for renewal was established using fear-potentiated startle as well as skin conductance and fear ratings. In addition, although contextual anxiety was greater in the acquisition context than in the extinction context during renewal, as assessed with startle, context conditioning did not influence the renewal effect. These data do not support the view that extinction conducted shortly after acquisition is context independent. Hence, they do not provide evidence that extinction can lead to erasure of a fear memory established via Pavlovian conditioning.
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Affiliation(s)
- Ruben P Alvarez
- Mood & Anxiety Disorders Program, National Institute of Mental Health, NIH, Bethesda, Maryland 20892, USA.
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43
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Abstract
Excessive fear and anxiety are hallmarks of a variety of disabling anxiety disorders that affect millions of people throughout the world. Hence, a greater understanding of the brain mechanisms involved in the inhibition of fear and anxiety is attracting increasing interest in the research community. In the laboratory, fear inhibition most often is studied through a procedure in which a previously fear conditioned organism is exposed to a fear-eliciting cue in the absence of any aversive event. This procedure results in a decline in conditioned fear responses that is attributed to a process called fear extinction. Extensive empirical work by behavioral psychologists has revealed basic behavioral characteristics of extinction, and theoretical accounts have emphasized extinction as a form of inhibitory learning as opposed to an erasure of acquired fear. Guided by this work, neuroscientists have begun to dissect the neural mechanisms involved, including the regions in which extinction-related plasticity occurs and the cellular and molecular processes that are engaged. The present paper will cover behavioral, theoretical and neurobiological work, and will conclude with a discussion of clinical implications.
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Affiliation(s)
- K M Myers
- Center for Behavioral Neuroscience, Emory University, Atlanta, GA, USA.
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44
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Kim J, Lee S, Park H, Song B, Hong I, Geum D, Shin K, Choi S. Blockade of amygdala metabotropic glutamate receptor subtype 1 impairs fear extinction. Biochem Biophys Res Commun 2007; 355:188-93. [PMID: 17292864 DOI: 10.1016/j.bbrc.2007.01.125] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2007] [Accepted: 01/24/2007] [Indexed: 11/19/2022]
Abstract
The metabotropic glutamate receptor subtype 1 (mGluR1) is thought to be crucial for several forms of memory, but its role in memory extinction has not been determined. Here, we examined a role of mGluR1 in the extinction of conditioned fear using microinjection of an mGluR1 antagonist, CPCCOEt, into the lateral amygdala (LA), a critical structure for fear conditioning and extinction. Intra-LA injection of 3 microg CPCCOEt impaired extinction that was initiated 48 h after the conditioning, but not that initiated 2h after the conditioning, indicating that the effectiveness of CPCCOEt depends upon the length of time since fear conditioning. The CPCCOEt injection failed to alter an mGluR1-like receptor (mGluR5)-dependent acquisition of fear memory, further supporting the specificity of the injected CPCCOEt on mGluR1. Together, our results suggest that amygdala mGluR1 plays a critical role in the extinction of learned fear, but not in the acquisition of fear memory.
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Affiliation(s)
- Jeongyeon Kim
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 151-742, Republic of Korea
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45
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Mao SC, Hsiao YH, Gean PW. Extinction training in conjunction with a partial agonist of the glycine site on the NMDA receptor erases memory trace. J Neurosci 2006; 26:8892-9. [PMID: 16943544 PMCID: PMC6675349 DOI: 10.1523/jneurosci.0365-06.2006] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2006] [Revised: 06/20/2006] [Accepted: 07/20/2006] [Indexed: 11/21/2022] Open
Abstract
Much evidence indicates that extinction training does not erase memory traces but instead forms inhibitory learning that prevents the expression of original memory. Fear conditioning induces long-term potentiation and drives synaptic insertion of AMPA receptors into the amygdala. Here we show that extinction training applied 1 h after training reversed the conditioning-induced increase in surface glutamate receptor subunit 1 (GluR1) in parallel with the inhibition of startle potentiation. However, if applied 24 h after training, extinction training reduced startle potentiation without influencing the GluR1 increase. We infused D-cycloserine (DCS), a partial agonist of the glycine site on the NMDA receptor, bilaterally into the amygdala 30 min before extinction training. This augmented the extinction training-elicited reduction in startle and reversed the conditioning-induced increase in GluR1. Delivery of five sets of tetanic stimulation (TS) to the external capsule produced a robust enhancement of synaptic responses in the lateral amygdala neurons that persisted for >2 h. Low-frequency stimulation applied 1 h after TS had no long-lasting effect on synaptic responses. The same treatments, however, induced depotentiation in the presence of DCS and reversed TS-induced increase in surface GluR1. Together, this study has two important findings: (1) whether a memory trace remains intact or is erased depends on the interval between conditioning and extinction training and (2) DCS facilitates the reversal of memory trace. DCS-induced augmentation of extinction and reversal of GluR1 surface expression are likely mediated by DCS-facilitated endocytosis of AMPA receptors.
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Affiliation(s)
- Sheng-Chun Mao
- Institute of Basic Medical Sciences and Department of Pharmacology, Center for Gene Regulation and Signal Transduction Research, National Cheng-Kung University, Tainan 701, Taiwan
| | - Ya-Hsin Hsiao
- Institute of Basic Medical Sciences and Department of Pharmacology, Center for Gene Regulation and Signal Transduction Research, National Cheng-Kung University, Tainan 701, Taiwan
| | - Po-Wu Gean
- Institute of Basic Medical Sciences and Department of Pharmacology, Center for Gene Regulation and Signal Transduction Research, National Cheng-Kung University, Tainan 701, Taiwan
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46
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Sigurdsson T, Doyère V, Cain CK, LeDoux JE. Long-term potentiation in the amygdala: a cellular mechanism of fear learning and memory. Neuropharmacology 2006; 52:215-27. [PMID: 16919687 DOI: 10.1016/j.neuropharm.2006.06.022] [Citation(s) in RCA: 212] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2006] [Revised: 06/27/2006] [Accepted: 06/28/2006] [Indexed: 11/19/2022]
Abstract
Much of the research on long-term potentiation (LTP) is motivated by the question of whether changes in synaptic strength similar to LTP underlie learning and memory. Here we discuss findings from studies on fear conditioning, a form of associative learning whose neural circuitry is relatively well understood, that may be particularly suited for addressing this question. We first review the evidence suggesting that fear conditioning is mediated by changes in synaptic strength at sensory inputs to the lateral nucleus of the amygdala. We then discuss several outstanding questions that will be important for future research on the role of synaptic plasticity in fear learning. The results gained from these studies may shed light not only on fear conditioning, but may also help unravel more general cellular mechanisms of learning and memory.
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Affiliation(s)
- Torfi Sigurdsson
- Center for Neural Science, New York University, 4 Washington Place, Room 809, New York, NY 10003, USA.
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47
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Barad M, Gean PW, Lutz B. The role of the amygdala in the extinction of conditioned fear. Biol Psychiatry 2006; 60:322-8. [PMID: 16919522 DOI: 10.1016/j.biopsych.2006.05.029] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2005] [Revised: 03/28/2006] [Accepted: 05/12/2006] [Indexed: 11/15/2022]
Abstract
The amygdala has long been known to play a central role in the acquisition and expression of fear. More recently, convergent evidence has implicated the amygdala in the extinction of fear as well. In rodents, some of this evidence comes from the infusion of drugs directly into the amygdala and, in particular, into the basolateral complex of the amygdala, during or after extinction learning. In vivo electrophysiology has identified cellular correlates of extinction learning and memory in the lateral nucleus of that structure. Human imaging experiments also indicate that amygdaloid activity correlates with extinction training. In addition, some studies have directly identified changes in molecular constituents of the basolateral amygdala. Together these experiments strongly indicate that the basolateral amygdala plays a crucial role in extinction learning. Interpreted in the light of these findings, several recent in vitro electrophysiology studies in amygdala-containing brain slices are suggestive of potential synaptic and circuit bases of extinction learning.
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Affiliation(s)
- Mark Barad
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, California 90095, USA.
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48
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Sotres-Bayon F, Cain CK, LeDoux JE. Brain mechanisms of fear extinction: historical perspectives on the contribution of prefrontal cortex. Biol Psychiatry 2006; 60:329-36. [PMID: 16412988 DOI: 10.1016/j.biopsych.2005.10.012] [Citation(s) in RCA: 285] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2005] [Revised: 09/07/2005] [Accepted: 10/18/2005] [Indexed: 11/24/2022]
Abstract
What brain regions are involved in regulating behavior when the emotional consequence of a stimulus changes from harmful to harmless? One way to address this question is to study the neural mechanisms underlying extinction of Pavlovian fear conditioning, an important form of emotional regulation that has direct relevance to the treatment of human fear and anxiety disorders. In fear extinction, the capacity of a conditioned stimulus to elicit fear is gradually reduced by repeatedly presenting it in the absence of any aversive consequence. In recent years there has been a dramatic increase in research on the brain mechanisms of fear extinction. One region that has received considerable attention as a component of the brain's extinction circuitry is the medial prefrontal cortex (mPFC). In the present article, we review the historical foundations of the modern notion that the mPFC plays a critical role in emotional regulation, a literature that was largely responsible for studies that explored the role of the mPFC in fear extinction. We also consider the role of the mPFC in a broader neural circuit for extinction that includes the amygdala and hippocampus.
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49
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Kamprath K, Marsicano G, Tang J, Monory K, Bisogno T, Marzo VD, Lutz B, Wotjak CT. Cannabinoid CB1 receptor mediates fear extinction via habituation-like processes. J Neurosci 2006; 26:6677-86. [PMID: 16793875 PMCID: PMC6673838 DOI: 10.1523/jneurosci.0153-06.2006] [Citation(s) in RCA: 167] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2006] [Revised: 04/05/2006] [Accepted: 04/25/2006] [Indexed: 11/21/2022] Open
Abstract
The interplay between fear expression and fear extinction provides an important prerequisite for adequate coping with aversive encounters. Current models propose that extinction of conditioned fear is mediated by associative safety learning. Here, we demonstrate that the cannabinoid CB1 receptor, which is crucially involved in fear extinction, is dispensable for associative safety learning. In fact, our results indicate that CB1 mediates fear extinction primarily via habituation-like processes. CB1 null-mutant mice were severely impaired not only in extinction of the fear response to a tone after fear conditioning but also in habituation of the fear response to a tone after sensitization with an inescapable footshock. Surprisingly, long-term habituation was generally affected even in situations with proper short-term adaptation, suggesting the existence of two separated CB1-dependent effector systems for short- and long-term fear adaptation. Our findings underscore the importance of habituation as a determinant of fear extinction in mice and characterize the cannabinoid CB1 receptor as an essential molecular correlate of this process.
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MESH Headings
- Acoustic Stimulation/methods
- Adaptation, Physiological/genetics
- Animals
- Behavior, Animal
- Conditioning, Psychological
- Evoked Potentials, Auditory/genetics
- Evoked Potentials, Auditory/physiology
- Extinction, Psychological/physiology
- Fear
- Habituation, Psychophysiologic/genetics
- Habituation, Psychophysiologic/physiology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Receptor, Cannabinoid, CB1/deficiency
- Receptor, Cannabinoid, CB1/physiology
- Time Factors
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50
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Affiliation(s)
- Mark Barad
- Veterans Health Administration, West Los Angeles, Los Angeles, California 90073, USA.
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