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Zou GJ, Chen ZR, Wang XQ, Cui YH, Li F, Li CQ, Wang LF, Huang FL. Microglial activation in the medial prefrontal cortex after remote fear recall participates in the regulation of auditory fear extinction. Eur J Pharmacol 2024; 978:176759. [PMID: 38901527 DOI: 10.1016/j.ejphar.2024.176759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 06/14/2024] [Accepted: 06/18/2024] [Indexed: 06/22/2024]
Abstract
Excessive or inappropriate fear responses can lead to anxiety-related disorders, such as post-traumatic stress disorder (PTSD). Studies have shown that microglial activation occurs after fear conditioning and that microglial inhibition impacts fear memory. However, the role of microglia in fear memory recall remains unclear. In this study, we investigated the activated profiles of microglia after the recall of remote-cued fear memory and the role of activated microglia in the extinction of remote-cued fear in adult male C57BL/6 mice. The results revealed that the expression of the microglia marker Iba1 increased in the medial prefrontal cortex (mPFC) at 10 min and 1 h following remote-cued fear recall, which was accompanied by amoeboid morphology. Inhibiting microglial activation through PLX3397 treatment before remote fear recall did not affect recall, reconsolidation, or regular extinction but facilitated recall-extinction and mitigated spontaneous recovery. Moreover, our results demonstrated reduced co-expression of Iba1 and postsynaptic density protein 95 (PSD95) in the mPFC, along with decreases in the p-PI3K/PI3K ratio, p-Akt/Akt ratio, and KLF4 expression after PLX3397 treatment. Our results suggest that microglial activation after remote fear recall impedes fear extinction through the pruning of synapses in the mPFC, accompanied by alterations in the expression of the PI3K/AKT/KLF4 pathway. This finding can help elucidate the mechanism involved in remote fear extinction, contributing to the theoretical foundation for the intervention and treatment of PTSD.
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Affiliation(s)
- Guang-Jing Zou
- Department of Anatomy and Neurobiology, School of Basic Medical Science, Central South University, Changsha, Hunan, 410013, China; School of Basic Medicine, Yiyang Medical College, Yiyang, Hunan, 413000, China
| | - Zhao-Rong Chen
- Department of Anatomy and Neurobiology, School of Basic Medical Science, Central South University, Changsha, Hunan, 410013, China; Hunan University of Chinese Medicine, Changsha, Hunan, 410219, China
| | - Xue-Qin Wang
- Hunan Provincial University Key Laboratory of the Fundamental and Clinical Research on Neurodegenerative Diseases, Changsha Medical University, Changsha, Hunan, 410219, China
| | - Yan-Hui Cui
- Department of Anatomy and Neurobiology, School of Basic Medical Science, Central South University, Changsha, Hunan, 410013, China
| | - Fang Li
- Department of Anatomy and Neurobiology, School of Basic Medical Science, Central South University, Changsha, Hunan, 410013, China
| | - Chang-Qi Li
- Department of Anatomy and Neurobiology, School of Basic Medical Science, Central South University, Changsha, Hunan, 410013, China
| | - Lai-Fa Wang
- Hunan Provincial University Key Laboratory of the Fundamental and Clinical Research on Neurodegenerative Diseases, Changsha Medical University, Changsha, Hunan, 410219, China.
| | - Fu-Lian Huang
- School of Basic Medicine, Yiyang Medical College, Yiyang, Hunan, 413000, China.
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2
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Premachandran H, Wilkin J, Arruda-Carvalho M. Minimizing Variability in Developmental Fear Studies in Mice: Toward Improved Replicability in the Field. Curr Protoc 2024; 4:e1040. [PMID: 38713136 DOI: 10.1002/cpz1.1040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
In rodents, the first weeks of postnatal life feature remarkable changes in fear memory acquisition, retention, extinction, and discrimination. Early development is also marked by profound changes in brain circuits underlying fear memory processing, with heightened sensitivity to environmental influences and stress, providing a powerful model to study the intersection between brain structure, function, and the impacts of stress. Nevertheless, difficulties related to breeding and housing young rodents, preweaning manipulations, and potential increased variability within that population pose considerable challenges to developmental fear research. Here we discuss several factors that may promote variability in studies examining fear conditioning in young rodents and provide recommendations to increase replicability. We focus primarily on experimental conditions, design, and analysis of rodent fear data, with an emphasis on mouse studies. The convergence of anatomical, synaptic, physiological, and behavioral changes during early life may increase variability, but careful practice and transparency in reporting may improve rigor and consensus in the field. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC.
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Affiliation(s)
- Hanista Premachandran
- Department of Psychology, University of Toronto Scarborough, Toronto, Ontario, Canada
- These authors contributed equally to this work
| | - Jennifer Wilkin
- Department of Psychology, University of Toronto Scarborough, Toronto, Ontario, Canada
- These authors contributed equally to this work
| | - Maithe Arruda-Carvalho
- Department of Psychology, University of Toronto Scarborough, Toronto, Ontario, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
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3
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Turkson S, van Rooij SJ, Powers A, Ofotokun I, Norrholm SD, N. Neigh G, Jovanovic T, Michopoulos V. HIV Interacts with Posttraumatic Stress Disorder to Impact Fear Psychophysiology in Trauma-Exposed Black Women. WOMEN'S HEALTH REPORTS (NEW ROCHELLE, N.Y.) 2024; 5:231-241. [PMID: 38523844 PMCID: PMC10960165 DOI: 10.1089/whr.2023.0133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 01/31/2024] [Indexed: 03/26/2024]
Abstract
Background The prevalence of posttraumatic stress disorder (PTSD) among people living with HIV (PLWH) is higher than in the general population and can impact health behaviors. The influence of HIV on PTSD psychophysiology requires further investigation due to implications for the treatment of PTSD in PLWH. Objective Utilizing fear-potentiated startle (FPS), we aimed to interrogate the influence of PTSD and HIV on fear responses. Materials and Methods Women (18-65 years of age) recruited from the Women's Interagency HIV Study in Atlanta, GA (n = 70, 26 without HIV and 44 with HIV), provided informed consent and completed a semistructured interview to assess trauma exposure and PTSD symptom severity. Participants also underwent an FPS paradigm to assess fear acquisition and extinction: Psychophysiological indices that measure how individuals learn new fear and then subsequently attempt to suppress this fear. Results Women with PTSD, who did not have HIV, exhibited a greater startle response compared to women without PTSD or HIV during late acquisition to both the danger cue, reinforced conditioned stimulus (CS+, p = 0.013)), and the safety cue, non-reinforced conditioned stimulus (CS-, p = 0.046)), whereas women living with HIV (WLH) and PTSD demonstrated blunted fear responses compared to women with PTSD only. During extinction, WLH comorbid with PTSD exhibited an increased fear response during the extinction period in comparison to all other groups (p = 0.023). Women without PTSD demonstrated a reduction in the fear response during extinction regardless of HIV status. Conclusion Our findings indicate that HIV further modifies fear psychophysiology in WLH with comorbid PTSD, highlighting the importance of considering HIV status in conjunction with PTSD treatment.
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Affiliation(s)
- Susie Turkson
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Sanne J.H. van Rooij
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Abigail Powers
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Ighovwerha Ofotokun
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Grady Health System, Atlanta, Georgia, USA
| | - Seth D. Norrholm
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University, Detroit, Michigan, USA
| | - Gretchen N. Neigh
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Tanja Jovanovic
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University, Detroit, Michigan, USA
| | - Vasiliki Michopoulos
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, Georgia, USA
- Emory National Primate Research Center, Atlanta, Georgia, USA
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4
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Palchaudhuri S, Osypenko D, Schneggenburger R. Fear Learning: An Evolving Picture for Plasticity at Synaptic Afferents to the Amygdala. Neuroscientist 2024; 30:87-104. [PMID: 35822657 DOI: 10.1177/10738584221108083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Unraveling the neuronal mechanisms of fear learning might allow neuroscientists to make links between a learned behavior and the underlying plasticity at specific synaptic connections. In fear learning, an innocuous sensory event such as a tone (called the conditioned stimulus, CS) acquires an emotional value when paired with an aversive outcome (unconditioned stimulus, US). Here, we review earlier studies that have shown that synaptic plasticity at thalamic and cortical afferents to the lateral amygdala (LA) is critical for the formation of auditory-cued fear memories. Despite the early progress, it has remained unclear whether there are separate synaptic inputs that carry US information to the LA to act as a teaching signal for plasticity at CS-coding synapses. Recent findings have begun to fill this gap by showing, first, that thalamic and cortical auditory afferents can also carry US information; second, that the release of neuromodulators contributes to US-driven teaching signals; and third, that synaptic plasticity additionally happens at connections up- and downstream of the LA. Together, a picture emerges in which coordinated synaptic plasticity in serial and parallel circuits enables the formation of a finely regulated fear memory.
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Affiliation(s)
- Shriya Palchaudhuri
- Laboratory of Synaptic Mechanisms, Brain Mind Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Denys Osypenko
- Laboratory of Synaptic Mechanisms, Brain Mind Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Ralf Schneggenburger
- Laboratory of Synaptic Mechanisms, Brain Mind Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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5
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Jung H, Han D, Lee C, Kaang BK. Synaptic Engram. ADVANCES IN NEUROBIOLOGY 2024; 38:131-145. [PMID: 39008014 DOI: 10.1007/978-3-031-62983-9_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
The concept of the engram refers to structural and/or physiological changes that underlie memory associations during learning. However, the precise biological basis of the engram remains elusive, with ongoing controversy regarding whether it resides at the cellular level or within the synaptic connections between activated cells. Here, we briefly review the studies investigating the cellular engram and the challenges they encounter. Subsequently, we delve into the biological basis of the engram within synaptic connections. In this regard, we introduce the history of synaptic engrams and discuss recent findings suggesting that synaptic plasticity serves as a substrate for memory. Additionally, we provide an overview of key technologies utilized in the study of synaptic plasticity.
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Affiliation(s)
- Hyunsu Jung
- Center for Cognition and Sociality, Life Science Institute, Institute for Basic Science (IBS), Daejeon, South Korea
- Interdisciplinary Program in Neuroscience, College of Natural Sciences, Seoul National University, Seoul, South Korea
| | - Daehee Han
- Center for Cognition and Sociality, Life Science Institute, Institute for Basic Science (IBS), Daejeon, South Korea
- Interdisciplinary Program in Neuroscience, College of Natural Sciences, Seoul National University, Seoul, South Korea
| | - Chaery Lee
- Center for Cognition and Sociality, Life Science Institute, Institute for Basic Science (IBS), Daejeon, South Korea
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea
| | - Bong-Kiun Kaang
- Center for Cognition and Sociality, Life Science Institute, Institute for Basic Science (IBS), Daejeon, South Korea.
- Interdisciplinary Program in Neuroscience, College of Natural Sciences, Seoul National University, Seoul, South Korea.
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea.
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6
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Sepahvand T, Nazari N, Qin T, Rajani V, Yuan Q. Olfactory threat extinction in the piriform cortex: An age-dependent employment of NMDA receptor-dependent long-term depression. Proc Natl Acad Sci U S A 2023; 120:e2309986120. [PMID: 37878718 PMCID: PMC10622944 DOI: 10.1073/pnas.2309986120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 09/27/2023] [Indexed: 10/27/2023] Open
Abstract
Extinction of threat memory is a measure of behavioral flexibility. In the absence of additional reinforcement, the extinction of learned behaviors allows animals and humans to adapt to their changing environment. Extinction mechanisms and their therapeutic implications for maladaptive learning have been extensively studied. However, how aging affects extinction learning is much less understood. Using a rat model of olfactory threat extinction, we show that the extinction of olfactory threat memory is impaired in aged Sprague-Darley rats. Following extinction training, long-term depression (LTD) in the piriform cortex (PC) was inducible ex vivo in aged rats and was NMDA receptor (NMDAR)-independent. On the other hand, adult rats acquired successful olfactory threat extinction, and LTD was not inducible following extinction training. Neuronal cFos activation in the posterior PC correlated with learning and extinction performance in rats. NMDAR blockade either systemically or locally in the PC during extinction training prevented successful extinction in adult rats, following which NMDAR-dependent LTD became inducible ex vivo. This suggests that extinction learning employs NMDAR-dependent LTD mechanisms in the PC of adult rats, thus occluding further LTD induction ex vivo. The rescue of olfactory threat extinction in aged rats by D-cycloserine, a partial NMDAR agonist, suggests that the impairment in olfactory threat extinction of aged animals may relate to NMDAR hypofunctioning and a lack of NMDAR-dependent LTD. These findings are consistent with an age-related switch from NMDAR-dependent to NMDAR-independent LTD in the PC. Optimizing NMDAR function in sensory cortices may improve learning and flexible behavior in the aged population.
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Affiliation(s)
- Tayebeh Sepahvand
- Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’s, NLA1B 3V6, Canada
| | - Negar Nazari
- Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’s, NLA1B 3V6, Canada
| | - Tian Qin
- Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’s, NLA1B 3V6, Canada
| | - Vishaal Rajani
- Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’s, NLA1B 3V6, Canada
| | - Qi Yuan
- Biomedical Sciences, Faculty of Medicine, Memorial University, St. John’s, NLA1B 3V6, Canada
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7
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Ratigan HC, Krishnan S, Smith S, Sheffield MEJ. A thalamic-hippocampal CA1 signal for contextual fear memory suppression, extinction, and discrimination. Nat Commun 2023; 14:6758. [PMID: 37875465 PMCID: PMC10598272 DOI: 10.1038/s41467-023-42429-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 10/10/2023] [Indexed: 10/26/2023] Open
Abstract
The adaptive regulation of fear memories is a crucial neural function that prevents inappropriate fear expression. Fear memories can be acquired through contextual fear conditioning (CFC) which relies on the hippocampus. The thalamic nucleus reuniens (NR) is necessary to extinguish contextual fear and innervates hippocampal CA1. However, the role of the NR-CA1 pathway in contextual fear is unknown. We developed a head-restrained virtual reality CFC paradigm, and demonstrate that mice can acquire and extinguish context-dependent fear responses. We found that inhibiting the NR-CA1 pathway following CFC lengthens the duration of fearful freezing epochs, increases fear generalization, and delays fear extinction. Using in vivo imaging, we recorded NR-axons innervating CA1 and found that NR-axons become tuned to fearful freezing following CFC. We conclude that the NR-CA1 pathway actively suppresses fear by disrupting contextual fear memory retrieval in CA1 during fearful freezing behavior, a process that also reduces fear generalization and accelerates extinction.
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Affiliation(s)
- Heather C Ratigan
- Department of Neurobiology, University of Chicago, Chicago, IL, 60615, USA
- Doctoral Program in Neurobiology, University of Chicago, Chicago, IL, 60615, USA
- Neuroscience Institute, University of Chicago, Chicago, IL, 60615, USA
| | - Seetha Krishnan
- Department of Neurobiology, University of Chicago, Chicago, IL, 60615, USA
- Neuroscience Institute, University of Chicago, Chicago, IL, 60615, USA
| | - Shai Smith
- Department of Neurobiology, University of Chicago, Chicago, IL, 60615, USA
- Undergraduate Program in Neuroscience, University of Chicago, Chicago, IL, 60615, USA
| | - Mark E J Sheffield
- Department of Neurobiology, University of Chicago, Chicago, IL, 60615, USA.
- Doctoral Program in Neurobiology, University of Chicago, Chicago, IL, 60615, USA.
- Neuroscience Institute, University of Chicago, Chicago, IL, 60615, USA.
- Undergraduate Program in Neuroscience, University of Chicago, Chicago, IL, 60615, USA.
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8
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Sepahvand T, Power KD, Qin T, Yuan Q. The Basolateral Amygdala: The Core of a Network for Threat Conditioning, Extinction, and Second-Order Threat Conditioning. BIOLOGY 2023; 12:1274. [PMID: 37886984 PMCID: PMC10604397 DOI: 10.3390/biology12101274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 09/14/2023] [Accepted: 09/20/2023] [Indexed: 10/28/2023]
Abstract
Threat conditioning, extinction, and second-order threat conditioning studied in animal models provide insight into the brain-based mechanisms of fear- and anxiety-related disorders and their treatment. Much attention has been paid to the role of the basolateral amygdala (BLA) in such processes, an overview of which is presented in this review. More recent evidence suggests that the BLA serves as the core of a greater network of structures in these forms of learning, including associative and sensory cortices. The BLA is importantly regulated by hippocampal and prefrontal inputs, as well as by the catecholaminergic neuromodulators, norepinephrine and dopamine, that may provide important prediction-error or learning signals for these forms of learning. The sensory cortices may be required for the long-term storage of threat memories. As such, future research may further investigate the potential of the sensory cortices for the long-term storage of extinction and second-order conditioning memories.
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Affiliation(s)
| | | | | | - Qi Yuan
- Biomedical Sciences, Faculty of Medicine, Memorial University, St John’s, NL A1B 3V6, Canada; (T.S.); (K.D.P.); (T.Q.)
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9
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Lee H, Kaang BK. How engram mediates learning, extinction, and relapse. Curr Opin Neurobiol 2023; 81:102723. [PMID: 37030026 DOI: 10.1016/j.conb.2023.102723] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 03/10/2023] [Accepted: 03/10/2023] [Indexed: 04/08/2023]
Abstract
Fear learning ensures survival through an expression of certain behavior as a conditioned fear response. Fear memory is processed and stored in a fear memory circuit, including the amygdala, hippocampus, and prefrontal cortex. A gradual decrease in conditioned fear response can be induced by fear extinction, which is mediated through the weakening of the original fear memory traces and the newly formed inhibition of those traces. Fear memory can also recover after extinction, which shows flexible control of the fear memory state. Here, we demonstrate how fear engram, which is a physical substrate of fear memory, changes during fear extinction and relapse by reviewing recent studies regarding engram.
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Affiliation(s)
- Hoonwon Lee
- School of Biological Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Bong-Kiun Kaang
- School of Biological Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea.
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10
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Khalil V, Faress I, Mermet-Joret N, Kerwin P, Yonehara K, Nabavi S. Subcortico-amygdala pathway processes innate and learned threats. eLife 2023; 12:e85459. [PMID: 37526552 PMCID: PMC10449383 DOI: 10.7554/elife.85459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 07/18/2023] [Indexed: 08/02/2023] Open
Abstract
Behavioral flexibility and timely reactions to salient stimuli are essential for survival. The subcortical thalamic-basolateral amygdala (BLA) pathway serves as a shortcut for salient stimuli ensuring rapid processing. Here, we show that BLA neuronal and thalamic axonal activity in mice mirror the defensive behavior evoked by an innate visual threat as well as an auditory learned threat. Importantly, perturbing this pathway compromises defensive responses to both forms of threats, in that animals fail to switch from exploratory to defensive behavior. Despite the shared pathway between the two forms of threat processing, we observed noticeable differences. Blocking β-adrenergic receptors impairs the defensive response to the innate but not the learned threats. This reduced defensive response, surprisingly, is reflected in the suppression of the activity exclusively in the BLA as the thalamic input response remains intact. Our side-by-side examination highlights the similarities and differences between innate and learned threat-processing, thus providing new fundamental insights.
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Affiliation(s)
- Valentina Khalil
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhusDenmark
- DANDRITE, The Danish Research Institute of Translational Neuroscience, Aarhus UniversityAarhusDenmark
- Center for Proteins in Memory – PROMEMO, Danish National Research Foundation, Aarhus UniversityAarhusDenmark
| | - Islam Faress
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhusDenmark
- DANDRITE, The Danish Research Institute of Translational Neuroscience, Aarhus UniversityAarhusDenmark
- Center for Proteins in Memory – PROMEMO, Danish National Research Foundation, Aarhus UniversityAarhusDenmark
- Department of Biomedicine, Aarhus UniversityAarhusDenmark
| | - Noëmie Mermet-Joret
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhusDenmark
- DANDRITE, The Danish Research Institute of Translational Neuroscience, Aarhus UniversityAarhusDenmark
- Center for Proteins in Memory – PROMEMO, Danish National Research Foundation, Aarhus UniversityAarhusDenmark
| | - Peter Kerwin
- DANDRITE, The Danish Research Institute of Translational Neuroscience, Aarhus UniversityAarhusDenmark
| | - Keisuke Yonehara
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhusDenmark
- Department of Biomedicine, Aarhus UniversityAarhusDenmark
- Multiscale Sensory Structure Laboratory, National Institute of GeneticsMishimaJapan
- Department of Genetics, The Graduate University for Advanced Studies (SOKENDAI)MishimaJapan
| | - Sadegh Nabavi
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhusDenmark
- DANDRITE, The Danish Research Institute of Translational Neuroscience, Aarhus UniversityAarhusDenmark
- Center for Proteins in Memory – PROMEMO, Danish National Research Foundation, Aarhus UniversityAarhusDenmark
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Ratigan HC, Krishnan S, Smith S, Sheffield MEJ. Direct Thalamic Inputs to Hippocampal CA1 Transmit a Signal That Suppresses Ongoing Contextual Fear Memory Retrieval. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.27.534420. [PMID: 37034812 PMCID: PMC10081195 DOI: 10.1101/2023.03.27.534420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Memory retrieval of fearful experiences is essential for survival but can be maladaptive if not appropriately suppressed. Fear memories can be acquired through contextual fear conditioning (CFC) which relies on the hippocampus. The thalamic subregion Nucleus Reuniens (NR) is necessary for contextual fear extinction and strongly projects to hippocampal subregion CA1. However, the NR-CA1 pathway has not been investigated during behavior, leaving unknown its role in contextual fear memory retrieval. We implement a novel head-restrained virtual reality CFC paradigm and show that inactivation of the NR-CA1 pathway prolongs fearful freezing epochs, induces fear generalization, and delays extinction. We use in vivo sub-cellular imaging to specifically record NR-axons innervating CA1 before and after CFC. We find NR-axons become selectively tuned to freezing only after CFC, and this activity is well-predicted by an encoding model. We conclude that the NR-CA1 pathway actively suppresses fear responses by disrupting ongoing hippocampal-dependent contextual fear memory retrieval.
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Affiliation(s)
- Heather C. Ratigan
- Department of Neurobiology, University of Chicago, Chicago, IL 60615, USA
- Doctoral Program in Neurobiology, University of Chicago, Chicago, IL 60615, USA
- Neuroscience Institute, University of Chicago, Chicago, IL 60615, USA
| | - Seetha Krishnan
- Department of Neurobiology, University of Chicago, Chicago, IL 60615, USA
- Neuroscience Institute, University of Chicago, Chicago, IL 60615, USA
| | - Shai Smith
- Department of Neurobiology, University of Chicago, Chicago, IL 60615, USA
- Undergraduate Program in Neuroscience, University of Chicago, Chicago, IL 60615, USA
| | - Mark E. J. Sheffield
- Department of Neurobiology, University of Chicago, Chicago, IL 60615, USA
- Doctoral Program in Neurobiology, University of Chicago, Chicago, IL 60615, USA
- Undergraduate Program in Neuroscience, University of Chicago, Chicago, IL 60615, USA
- Neuroscience Institute, University of Chicago, Chicago, IL 60615, USA
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12
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Dynamic tripartite construct of interregional engram circuits underlies forgetting of extinction memory. Mol Psychiatry 2022; 27:4077-4091. [PMID: 35804093 DOI: 10.1038/s41380-022-01684-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 06/15/2022] [Accepted: 06/27/2022] [Indexed: 02/07/2023]
Abstract
Fear extinction allows for adaptive control of learned fear responses but often fails, resulting in a renewal or spontaneous recovery of the extinguished fear, i.e., forgetting of the extinction memory readily occurs. Using an activity-dependent neuronal labeling strategy, we demonstrate that engram neurons for fear extinction memory are dynamically positioned in the medial prefrontal cortex (mPFC), basolateral amygdala (BLA), and ventral hippocampus (vHPC), which constitute an engram construct in the term of directional engram synaptic connectivity from the BLA or vHPC to mPFC, but not that in the opposite direction, for retrieval of extinction memory. Fear renewal or spontaneous recovery switches the extinction engram construct from an accessible to inaccessible state, whereas additional extinction learning or optogenetic induction of long-term potentiation restores the directional engram connectivity and prevents the return of fear. Thus, the plasticity of engram construct underlies forgetting of extinction memory.
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13
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Sadeghi MA, Hemmati S, Nassireslami E, Yousefi Zoshk M, Hosseini Y, Abbasian K, Chamanara M. Targeting neuronal nitric oxide synthase and the nitrergic system in post-traumatic stress disorder. Psychopharmacology (Berl) 2022; 239:3057-3082. [PMID: 36029333 DOI: 10.1007/s00213-022-06212-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 08/04/2022] [Indexed: 12/22/2022]
Abstract
RATIONALE Current pharmacological approaches to treatment of post-traumatic stress disorder (PTSD) lack adequate effectiveness. As a result, identifying new molecular targets for drug development is necessary. Furthermore, fear learning and memory in PTSD can undergo different phases, such as fear acquisition, consolidation, and extinction. Each phase may involve different cellular pathways and brain regions. As a result, effective management of PTSD requires mindfulness of the timing of drug administration. One of the molecular targets currently under intense investigation is the N-methyl-D-aspartate (NMDA)-type glutamate receptor (NMDAR). However, despite the therapeutic efficacy of drugs targeting NMDAR, their translation into clinical use has been challenging due to their various side effects. One possible solution to this problem is to target signaling proteins downstream to NMDAR to improve targeting specificity. One of these proteins is the neuronal nitric oxide synthase (nNOS), which is activated following calcium influx through the NMDAR. OBJECTIVE In this paper, we review the literature on the pharmacological modulation of nNOS in animal models of PTSD to evaluate its therapeutic potential. Furthermore, we attempt to decipher the inconsistencies observed between the findings of these studies based on the specific phase of fear learning which they had targeted. RESULTS Inhibition of nNOS may inhibit fear acquisition and recall, while not having a significant effect on fear consolidation and extinction. However, it may improve extinction consolidation or reconsolidation blockade. CONCLUSIONS Modulation of nNOS has therapeutic potential against PTSD and warrants further development for use in the clinical setting.
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Affiliation(s)
- Mohammad Amin Sadeghi
- Toxicology Research Center, AJA University of Medical Sciences, Tehran, Iran.,Department of Pharmacology, School of Medicine, AJA University of Medical Sciences, Tehran, Iran
| | - Sara Hemmati
- School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Ehsan Nassireslami
- Toxicology Research Center, AJA University of Medical Sciences, Tehran, Iran.,Department of Pharmacology, School of Medicine, AJA University of Medical Sciences, Tehran, Iran
| | | | - Yasaman Hosseini
- Cognitive Neuroscience Center, School of Medicine, AJA University of Medical Sciences, Tehran, Iran
| | - Kourosh Abbasian
- Management and Health Economics Department, AJA University of Medical Sciences, Tehran, Iran
| | - Mohsen Chamanara
- Toxicology Research Center, AJA University of Medical Sciences, Tehran, Iran. .,Department of Pharmacology, School of Medicine, AJA University of Medical Sciences, Tehran, Iran.
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14
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Interrogating structural plasticity among synaptic engrams. Curr Opin Neurobiol 2022; 75:102552. [DOI: 10.1016/j.conb.2022.102552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 04/08/2022] [Accepted: 04/13/2022] [Indexed: 11/21/2022]
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15
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Anderson MC, Floresco SB. Prefrontal-hippocampal interactions supporting the extinction of emotional memories: the retrieval stopping model. Neuropsychopharmacology 2022; 47:180-195. [PMID: 34446831 PMCID: PMC8616908 DOI: 10.1038/s41386-021-01131-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 02/07/2023]
Abstract
Neuroimaging has revealed robust interactions between the prefrontal cortex and the hippocampus when people stop memory retrieval. Efforts to stop retrieval can arise when people encounter reminders to unpleasant thoughts they prefer not to think about. Retrieval stopping suppresses hippocampal and amygdala activity, especially when cues elicit aversive memory intrusions, via a broad inhibitory control capacity enabling prepotent response suppression. Repeated retrieval stopping reduces intrusions of unpleasant memories and diminishes their affective tone, outcomes resembling those achieved by the extinction of conditioned emotional responses. Despite this resemblance, the role of inhibitory fronto-hippocampal interactions and retrieval stopping broadly in extinction has received little attention. Here we integrate human and animal research on extinction and retrieval stopping. We argue that reconceptualising extinction to integrate mnemonic inhibitory control with learning would yield a greater understanding of extinction's relevance to mental health. We hypothesize that fear extinction spontaneously engages retrieval stopping across species, and that controlled suppression of hippocampal and amygdala activity by the prefrontal cortex reduces fearful thoughts. Moreover, we argue that retrieval stopping recruits extinction circuitry to achieve affect regulation, linking extinction to how humans cope with intrusive thoughts. We discuss novel hypotheses derived from this theoretical synthesis.
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Affiliation(s)
- Michael C Anderson
- MRC Cognition & Brain Sciences Unit, University of Cambridge, Cambridge, UK.
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK.
| | - Stan B Floresco
- Department of Psychology, and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
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16
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Qing X, Xu YL, Liu H, Liu XS. The influence of anesthesia and surgery on fear extinction. Neurosci Lett 2022; 766:136347. [PMID: 34808271 DOI: 10.1016/j.neulet.2021.136347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 08/29/2021] [Accepted: 11/09/2021] [Indexed: 10/19/2022]
Abstract
Accumulating evidence has demonstrated significant clinical post-traumatic stress disorder (PTSD) symptoms after anesthesia or surgery. Fear extinction dysfunction is a notable feature of PTSD. Although anesthetics and surgery profoundly affect memory processes, their designated effects on fear extinction have not been dissertated. Previous studies have suggested that innate immune system activation disrupts fear extinction, and surgery has been shown to increase the inflammatory response. Thus, in the current study, we examined the effects of propofol, sevoflurane, dexmedetomidine and surgery on fear extinction in adolescent mice, and further tested whether dexmedetomidine could reverse the injury effect of surgery on fear extinction through its anti-inflammatory effects. Our results showed that propofol (200 mg/kg) impaired the acquisition and recall of cued fear extinction, and surgery disrupted cued fear extinction acquisition/recall and consolidation. In contrast to cued fear extinction, contextual fear extinction was not affected by propofol or surgery. Moreover, dexmedetomidine prevented surgery-induced impairment of cued extinction acquisition and recall but not consolidation. Finally, TNF-α and IL-6 levels in the ventromedial prefrontal cortex were not necessary for the dexmedetomidine treatment effect of surgery-induced fear extinction dysfunction. The study results showed that propofol and surgery selective impaired the cued fear extinction stage in adolescent mice, and dexmedetomidine may unleash a protective effect in preventing postoperative PTSD.
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Affiliation(s)
- Xin Qing
- Department of Anesthesiology, the First Affiliated Hospital of Anhui Medical University, Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, China
| | - Yuan-Ling Xu
- Department of Anesthesiology, the First Affiliated Hospital of Anhui Medical University, Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, China
| | - Hu Liu
- Department of Anesthesiology, the First Affiliated Hospital of Anhui Medical University, Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, China.
| | - Xue-Sheng Liu
- Department of Anesthesiology, the First Affiliated Hospital of Anhui Medical University, Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, China.
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17
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Baldi E, Costa A, Rani B, Passani MB, Blandina P, Romano A, Provensi G. Oxytocin and Fear Memory Extinction: Possible Implications for the Therapy of Fear Disorders? Int J Mol Sci 2021; 22:10000. [PMID: 34576161 PMCID: PMC8467761 DOI: 10.3390/ijms221810000] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/07/2021] [Accepted: 09/10/2021] [Indexed: 02/07/2023] Open
Abstract
Several psychiatric conditions such as phobias, generalized anxiety, and post-traumatic stress disorder (PTSD) are characterized by pathological fear and anxiety. The main therapeutic approach used in the management of these disorders is exposure-based therapy, which is conceptually based upon fear extinction with the formation of a new safe memory association, allowing the reduction in behavioral conditioned fear responses. Nevertheless, this approach is only partially resolutive, since many patients have difficulty following the demanding and long process, and relapses are frequently observed over time. One strategy to improve the efficacy of the cognitive therapy is the combination with pharmacological agents. Therefore, the identification of compounds able to strengthen the formation and persistence of the inhibitory associations is a key goal. Recently, growing interest has been aroused by the neuropeptide oxytocin (OXT), which has been shown to have anxiolytic effects. Furthermore, OXT receptors and binding sites have been found in the critical brain structures involved in fear extinction. In this review, the recent literature addressing the complex effects of OXT on fear extinction at preclinical and clinical levels is discussed. These studies suggest that the OXT roles in fear behavior are due to its local effects in several brain regions, most notably, distinct amygdaloid regions.
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Affiliation(s)
- Elisabetta Baldi
- Section of Physiological Sciences, Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy;
| | - Alessia Costa
- Section of Clinical Pharmacology and Oncology, Department of Health Sciences (DSS), University of Florence, 50139 Florence, Italy; (A.C.); (B.R.); (M.B.P.)
| | - Barbara Rani
- Section of Clinical Pharmacology and Oncology, Department of Health Sciences (DSS), University of Florence, 50139 Florence, Italy; (A.C.); (B.R.); (M.B.P.)
| | - Maria Beatrice Passani
- Section of Clinical Pharmacology and Oncology, Department of Health Sciences (DSS), University of Florence, 50139 Florence, Italy; (A.C.); (B.R.); (M.B.P.)
| | - Patrizio Blandina
- Section of Pharmacology of Toxicology, Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, 50139 Florence, Italy;
| | - Adele Romano
- Department of Physiology and Pharmacology ‘V. Erspamer’, Sapienza University of Rome, 00185 Rome, Italy;
| | - Gustavo Provensi
- Section of Pharmacology of Toxicology, Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, 50139 Florence, Italy;
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18
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Ma X, Vuyyuru H, Munsch T, Endres T, Lessmann V, Meis S. ProBDNF Dependence of LTD and Fear Extinction Learning in the Amygdala of Adult Mice. Cereb Cortex 2021; 32:1350-1364. [PMID: 34470044 DOI: 10.1093/cercor/bhab265] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 11/12/2022] Open
Abstract
Neurotrophins are secreted proteins that control survival, differentiation, and synaptic plasticity. While mature neurotrophins regulate these functions via tyrosine kinase signaling (Trk), uncleaved pro-neurotrophins bind preferentially to the p75 neurotrophin receptor (p75NTR) and often exert opposite effects to those of mature neurotrophins. In the amygdala, brain-derived neurotrophic factor (BDNF) enables long-term potentiation as well as fear and fear extinction learning. In the present study, we focused on the impact of mature BDNF and proBDNF signaling on long-term depression (LTD) in the lateral amygdala (LA). Hence, we conducted extracellular field potential recordings in an in vitro slice preparation and recorded LTD in cortical and thalamic afferents to the LA. LTD was unchanged by acute block of BDNF/TrkB signaling. In contrast, LTD was inhibited by blocking p75NTR signaling, by disinhibition of the proteolytic cleavage of proBDNF into mature BDNF, and by preincubation with a function-blocking anti-proBDNF antibody. Since LTD-like processes in the amygdala are supposed to be related to fear extinction learning, we locally inhibited p75NTR signaling in the amygdala during or after fear extinction training, resulting in impaired fear extinction memory. Overall, these results suggest that in the amygdala proBDNF/p75NTR signaling plays a pivotal role in LTD and fear extinction learning.
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Affiliation(s)
- Xiaoyun Ma
- Institut für Physiologie, Otto-von-Guericke-Universität, D-39120 Magdeburg, Germany
| | - Harish Vuyyuru
- Institut für Physiologie, Otto-von-Guericke-Universität, D-39120 Magdeburg, Germany
| | - Thomas Munsch
- Institut für Physiologie, Otto-von-Guericke-Universität, D-39120 Magdeburg, Germany.,Center for Behavioral Brain Sciences, Universitätsplatz 2, D-39106 Magdeburg, Germany
| | - Thomas Endres
- Institut für Physiologie, Otto-von-Guericke-Universität, D-39120 Magdeburg, Germany
| | - Volkmar Lessmann
- Institut für Physiologie, Otto-von-Guericke-Universität, D-39120 Magdeburg, Germany.,Center for Behavioral Brain Sciences, Universitätsplatz 2, D-39106 Magdeburg, Germany
| | - Susanne Meis
- Institut für Physiologie, Otto-von-Guericke-Universität, D-39120 Magdeburg, Germany.,Center for Behavioral Brain Sciences, Universitätsplatz 2, D-39106 Magdeburg, Germany
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19
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Choi DI, Kim J, Lee H, Kim JI, Sung Y, Choi JE, Venkat SJ, Park P, Jung H, Kaang BK. Synaptic correlates of associative fear memory in the lateral amygdala. Neuron 2021; 109:2717-2726.e3. [PMID: 34363751 DOI: 10.1016/j.neuron.2021.07.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 04/16/2021] [Accepted: 07/01/2021] [Indexed: 01/25/2023]
Abstract
Successful adaptation to the environment requires an accurate response to external threats by recalling specific memories. Memory formation and recall require engram cell activity and synaptic strengthening among activated neuronal ensembles. However, elucidation of the underlying neural substrates of associative fear memory has remained limited without a direct interrogation of extinction-induced changes of specific synapses that encode a specific auditory fear memory. Using dual-eGRASP (enhanced green fluorescent protein reconstitution across synaptic partners), we found that synapses among activated neuronal ensembles or activated synaptic ensembles showed a significantly larger spine morphology at auditory cortex (AC)-to-lateral amygdala (LA) projections after auditory fear conditioning in mice. Fear extinction reversed these enhanced synaptic ensemble spines, whereas re-conditioning with the same tone and shock restored the spine size of the synaptic ensemble. We suggest that synaptic ensembles encode and represent different fear memory states.
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Affiliation(s)
- Dong Il Choi
- School of Biological Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 08826, South Korea
| | - Jooyoung Kim
- School of Biological Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 08826, South Korea
| | - Hoonwon Lee
- School of Biological Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 08826, South Korea
| | - Ji-Il Kim
- School of Biological Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 08826, South Korea
| | - Yongmin Sung
- School of Biological Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 08826, South Korea
| | - Ja Eun Choi
- School of Biological Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 08826, South Korea
| | - S Jayakumar Venkat
- School of Biological Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 08826, South Korea
| | - Pojeong Park
- School of Biological Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 08826, South Korea
| | - Hyunsu Jung
- School of Biological Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 08826, South Korea
| | - Bong-Kiun Kaang
- School of Biological Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul 08826, South Korea.
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20
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Han DH, Park P, Choi DI, Bliss TVP, Kaang BK. The essence of the engram: Cellular or synaptic? Semin Cell Dev Biol 2021; 125:122-135. [PMID: 34103208 DOI: 10.1016/j.semcdb.2021.05.033] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/28/2021] [Accepted: 05/31/2021] [Indexed: 10/21/2022]
Abstract
Memory is composed of various phases including cellular consolidation, systems consolidation, reconsolidation, and extinction. In the last few years it has been shown that simple association memories can be encoded by a subset of the neuronal population called engram cells. Activity of these cells is necessary and sufficient for the recall of association memory. However, it is unclear which molecular mechanisms allow cellular engrams to encode the diverse phases of memory. Further research is needed to examine the possibility that it is the synapses between engram cells (the synaptic engram) that constitute the memory. In this review we summarize recent findings on cellular engrams with a focus on different phases of memory, and discuss the distinct molecular mechanism required for cellular and synaptic engrams.
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Affiliation(s)
- Dae Hee Han
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Pojeong Park
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Dong Il Choi
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Tim V P Bliss
- Group leader emeritus, The Francis Crick Institute, 1 Midland Rd, Somers Town, London NW1 1AT, UK
| | - Bong-Kiun Kaang
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea.
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21
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Lee J, An B, Choi S. Longitudinal recordings of single units in the basal amygdala during fear conditioning and extinction. Sci Rep 2021; 11:11177. [PMID: 34045527 PMCID: PMC8159982 DOI: 10.1038/s41598-021-90530-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 04/30/2021] [Indexed: 02/04/2023] Open
Abstract
The balance between activities of fear neurons and extinction neurons in the basolateral nucleus of the basal amygdala (BAL) has been hypothesized to encode fear states after extinction. However, it remains unclear whether these neurons are solely responsible for encoding fear states. In this study, we stably recorded single-unit activities in the BAL during fear conditioning and extinction for 3 days, providing a comprehensive view on how different BAL neurons respond during fear learning. We found BAL neurons that showed excitatory responses to the conditioned stimulus (CS) after fear conditioning ('conditioning-potentiated neurons') and another population that showed excitatory responses to the CS after extinction ('extinction-potentiated neurons'). Interestingly, we also found BAL neurons that developed inhibitory responses to the CS after fear conditioning ('conditioning-inhibited neurons') or after extinction ('extinction-inhibited neurons'). BAL neurons that showed excitatory responses to the CS displayed various functional connectivity with each other, whereas less connectivity was observed among neurons with inhibitory responses to the CS. Intriguingly, we found correlative neuronal activities between conditioning-potentiated neurons and neurons with inhibitory responses to the CS. Our findings suggest that distinct BAL neurons, which are responsive to the CS with excitation or inhibition, encode various facets of fear conditioning and extinction.
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Affiliation(s)
- Junghwa Lee
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea
| | - Bobae An
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Sukwoo Choi
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea.
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22
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Hagihara KM, Bukalo O, Zeller M, Aksoy-Aksel A, Karalis N, Limoges A, Rigg T, Campbell T, Mendez A, Weinholtz C, Mahn M, Zweifel LS, Palmiter RD, Ehrlich I, Lüthi A, Holmes A. Intercalated amygdala clusters orchestrate a switch in fear state. Nature 2021; 594:403-407. [PMID: 34040259 DOI: 10.1038/s41586-021-03593-1] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 04/28/2021] [Indexed: 12/14/2022]
Abstract
Adaptive behaviour necessitates the formation of memories for fearful events, but also that these memories can be extinguished. Effective extinction prevents excessive and persistent reactions to perceived threat, as can occur in anxiety and 'trauma- and stressor-related' disorders1. However, although there is evidence that fear learning and extinction are mediated by distinct neural circuits, the nature of the interaction between these circuits remains poorly understood2-6. Here, through a combination of in vivo calcium imaging, functional manipulations, and slice physiology, we show that distinct inhibitory clusters of intercalated neurons (ITCs) in the mouse amygdala exert diametrically opposed roles during the acquisition and retrieval of fear extinction memory. Furthermore, we find that the ITC clusters antagonize one another through mutual synaptic inhibition and differentially access functionally distinct cortical- and midbrain-projecting amygdala output pathways. Our findings show that the balance of activity between ITC clusters represents a unique regulatory motif that orchestrates a distributed neural circuitry, which in turn regulates the switch between high- and low-fear states. These findings suggest that the ITCs have a broader role in a range of amygdala functions and associated brain states that underpins the capacity to adapt to salient environmental demands.
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Affiliation(s)
- Kenta M Hagihara
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Olena Bukalo
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA
| | - Martin Zeller
- Hertie Institute for Clinical Brain Research, Tübingen, Germany.,Centre for Integrative Neuroscience, Tübingen, Germany
| | - Ayla Aksoy-Aksel
- Hertie Institute for Clinical Brain Research, Tübingen, Germany.,Centre for Integrative Neuroscience, Tübingen, Germany.,Department of Neurobiology, Institute of Biomaterials and Biomolecular Systems, University of Stuttgart, Stuttgart, Germany
| | - Nikolaos Karalis
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Aaron Limoges
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA
| | - Tanner Rigg
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA
| | - Tiffany Campbell
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA
| | - Adriana Mendez
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA
| | - Chase Weinholtz
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA
| | - Mathias Mahn
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Larry S Zweifel
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA.,Department of Pharmacology, University of Washington, Seattle, WA, USA
| | - Richard D Palmiter
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA.,Department of Biochemistry, University of Washington, Seattle, WA, USA.,Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Ingrid Ehrlich
- Hertie Institute for Clinical Brain Research, Tübingen, Germany.,Centre for Integrative Neuroscience, Tübingen, Germany.,Department of Neurobiology, Institute of Biomaterials and Biomolecular Systems, University of Stuttgart, Stuttgart, Germany
| | - Andreas Lüthi
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| | - Andrew Holmes
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA.
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23
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Ferland-Beckham C, Chaby LE, Daskalakis NP, Knox D, Liberzon I, Lim MM, McIntyre C, Perrine SA, Risbrough VB, Sabban EL, Jeromin A, Haas M. Systematic Review and Methodological Considerations for the Use of Single Prolonged Stress and Fear Extinction Retention in Rodents. Front Behav Neurosci 2021; 15:652636. [PMID: 34054443 PMCID: PMC8162789 DOI: 10.3389/fnbeh.2021.652636] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 03/22/2021] [Indexed: 12/14/2022] Open
Abstract
Posttraumatic stress disorder (PTSD) is a mental health condition triggered by experiencing or witnessing a terrifying event that can lead to lifelong burden that increases mortality and adverse health outcomes. Yet, no new treatments have reached the market in two decades. Thus, screening potential interventions for PTSD is of high priority. Animal models often serve as a critical translational tool to bring new therapeutics from bench to bedside. However, the lack of concordance of some human clinical trial outcomes with preclinical animal efficacy findings has led to a questioning of the methods of how animal studies are conducted and translational validity established. Thus, we conducted a systematic review to determine methodological variability in studies that applied a prominent animal model of trauma-like stress, single prolonged stress (SPS). The SPS model has been utilized to evaluate a myriad of PTSD-relevant outcomes including extinction retention. Rodents exposed to SPS express an extinction retention deficit, a phenotype identified in humans with PTSD, in which fear memory is aberrantly retained after fear memory extinction. The current systematic review examines methodological variation across all phases of the SPS paradigm, as well as strategies for behavioral coding, data processing, statistical approach, and the depiction of data. Solutions for key challenges and sources of variation within these domains are discussed. In response to methodological variation in SPS studies, an expert panel was convened to generate methodological considerations to guide researchers in the application of SPS and the evaluation of extinction retention as a test for a PTSD-like phenotype. Many of these guidelines are applicable to all rodent paradigms developed to model trauma effects or learned fear processes relevant to PTSD, and not limited to SPS. Efforts toward optimizing preclinical model application are essential for enhancing the reproducibility and translational validity of preclinical findings, and should be conducted for all preclinical psychiatric research models.
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Affiliation(s)
| | - Lauren E Chaby
- Cohen Veterans Bioscience, New York City, NY, United States
| | - Nikolaos P Daskalakis
- Department of Psychiatry, Harvard Medical School, Boston, MA, United States.,McLean Hospital, Belmont, MA, United States
| | - Dayan Knox
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE, United States
| | - Israel Liberzon
- Department of Psychiatry, Texas A&M University, Bryan, TX, United States
| | - Miranda M Lim
- Departments of Neurology, Behavioral Neuroscience, Medicine, Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, United States.,Sleep Disorders Clinic, VA Portland Health Care System, Portland, OR, United States
| | - Christa McIntyre
- Department of Neuroscience, The University of Texas at Dallas, Richardson, TX, United States
| | - Shane A Perrine
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, MI, United States.,Research Service, John. D. Dingell VA Medical Center, Detroit, MI, United States
| | - Victoria B Risbrough
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, United States.,Center for Excellence in Stress and Mental Health, VA San Diego Healthcare System, San Diego, CA, United States
| | - Esther L Sabban
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY, United States
| | | | - Magali Haas
- Cohen Veterans Bioscience, New York City, NY, United States
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24
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Urrieta E, Escobar ML. Metaplastic regulation of neocortical long-term depression in vivo is sensitive to distinct phases of conditioned taste aversion. Neurobiol Learn Mem 2021; 182:107449. [PMID: 33915300 DOI: 10.1016/j.nlm.2021.107449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 04/12/2021] [Accepted: 04/22/2021] [Indexed: 10/21/2022]
Abstract
Metaplasticity refers to the persistent modification, by previous activity, in the ability to induce synaptic plasticity. Accumulated evidence has proposed that metaplasticity contributes to network function and cognitive processes such as learning and memory. In this regard, it has been observed that training in several behavioral tasks modifies the possibility to induce subsequent synaptic plasticity, such as long-term potentiation (LTP) and long-term depression (LTD). For instance, our previous studies have shown that conditioned taste aversion (CTA) training prevents the induction of in vivo LTP in the projection from the basolateral nucleus of the amygdala to the insular cortex (BLA-IC). Likewise, we reported that extinction of CTA allows induction but not maintenance of LTP in the same pathway. Besides, we showed that it is possible to express in vivo low-frequency stimulation LTD in the BLA-IC projection and that its induction prior to CTA training facilitates the extinction of this task. However, until now, little is known about the participation of LTD on metaplastic processes. The present study aimed to analyze whether CTA training modifies the expression of in vivo LTD in the BLA-IC projection. To do so, animals received low-frequency stimulation to induce IC-LTD 48 h after CTA training. Our results show that CTA training occludes the subsequent induction of LTD in the BLA-IC pathway in a retrieval-dependent manner. These findings reveal that CTA elicits a metaplastic regulation of long-lasting changes in the IC synaptic strength, as well as that specific phases of learning differentially take part in adjusting the expression of synaptic plasticity in neocortical regions.
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Affiliation(s)
- Esteban Urrieta
- División de Investigación y Estudios de Posgrado, Facultad de Psicología, Universidad Nacional Autónoma de México, 04510, Mexico
| | - Martha L Escobar
- División de Investigación y Estudios de Posgrado, Facultad de Psicología, Universidad Nacional Autónoma de México, 04510, Mexico.
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25
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Qin C, Bian XL, Wu HY, Xian JY, Cai CY, Lin YH, Zhou Y, Kou XL, Chang L, Luo CX, Zhu DY. Dorsal Hippocampus to Infralimbic Cortex Circuit is Essential for the Recall of Extinction Memory. Cereb Cortex 2021; 31:1707-1718. [PMID: 33188393 DOI: 10.1093/cercor/bhaa320] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 10/07/2020] [Accepted: 10/07/2020] [Indexed: 12/30/2022] Open
Abstract
Posttraumatic stress disorder subjects usually show impaired recall of extinction memory, leading to extinguished fear relapses. However, little is known about the neural mechanisms underlying the impaired recall of extinction memory. We show here that the activity of dorsal hippocampus (dHPC) to infralimbic (IL) cortex circuit is essential for the recall of fear extinction memory in male mice. There were functional neural projections from the dHPC to IL. Using optogenetic manipulations, we observed that silencing the activity of dHPC-IL circuit inhibited recall of extinction memory while stimulating the activity of dHPC-IL circuit facilitated recall of extinction memory. "Impairment of extinction consolidation caused by" conditional deletion of extracellular signal-regulated kinase 2 (ERK2) in the IL prevented the dHPC-IL circuit-mediated recall of extinction memory. Moreover, silencing the dHPC-IL circuit abolished the effect of intra-IL microinjection of ERK enhancer on the recall of extinction memory. Together, we identify a dHPC to IL circuit that mediates the recall of extinction memory, and our data suggest that the dysfunction of dHPC-IL circuit and/or impaired extinction consolidation may contribute to extinguished fear relapses.
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Affiliation(s)
- Cheng Qin
- Department of Pharmacology, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Xin-Lan Bian
- Department of Pharmacology, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Hai-Yin Wu
- Department of Pharmacology, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Jia-Yun Xian
- Department of Pharmacology, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Cheng-Yun Cai
- Department of Pharmacology, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Yu-Hui Lin
- Department of Pharmacology, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Ying Zhou
- Department of Pharmacology, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Xiao-Lin Kou
- Department of Pharmacology, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Lei Chang
- Department of Pharmacology, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Chun-Xia Luo
- Department of Pharmacology, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
- Department of Pharmacology, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangzhou 510000, China
| | - Dong-Ya Zhu
- Department of Pharmacology, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
- Institution of Stem Cells and Neuroregeneration, Nanjing Medical University, Nanjing 211166, China
- Department of Pharmacology, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangzhou 510000, China
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26
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Mattera A, Pagani M, Baldassarre G. A Computational Model Integrating Multiple Phenomena on Cued Fear Conditioning, Extinction, and Reinstatement. Front Syst Neurosci 2020; 14:569108. [PMID: 33132856 PMCID: PMC7550679 DOI: 10.3389/fnsys.2020.569108] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 08/13/2020] [Indexed: 11/23/2022] Open
Abstract
Conditioning, extinction, and reinstatement are fundamental learning processes of animal adaptation, also strongly involved in human pathologies such as post-traumatic stress disorder, anxiety, depression, and dependencies. Cued fear conditioning, extinction, restatement, and systematic manipulations of the underlying brain amygdala and medial prefrontal cortex, represent key experimental paradigms to study such processes. Numerous empirical studies have revealed several aspects and the neural systems and plasticity underlying them, but at the moment we lack a comprehensive view. Here we propose a computational model based on firing rate leaky units that contributes to such integration by accounting for 25 different experiments on fear conditioning, extinction, and restatement, on the basis of a single neural architecture having a structure and plasticity grounded in known brain biology. This allows the model to furnish three novel contributions to understand these open issues: (a) the functioning of the central and lateral amygdala system supporting conditioning; (b) the role played by the endocannabinoids system in within- and between-session extinction; (c) the formation of three important types of neurons underlying fear processing, namely fear, extinction, and persistent neurons. The model integration of the results on fear conditioning goes substantially beyond what was done in previous models.
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Affiliation(s)
- Andrea Mattera
- Institute of Cognitive Sciences and Technologies, National Research Council, Rome, Italy
| | - Marco Pagani
- Institute of Cognitive Sciences and Technologies, National Research Council, Rome, Italy
| | - Gianluca Baldassarre
- Institute of Cognitive Sciences and Technologies, National Research Council, Rome, Italy
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Song S, Kim J, Park K, Lee J, Park S, Lee S, Kim J, Hong I, Song B, Choi S. GSK-3β activation is required for ZIP-induced disruption of learned fear. Sci Rep 2020; 10:18227. [PMID: 33106552 PMCID: PMC7588416 DOI: 10.1038/s41598-020-75130-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 10/05/2020] [Indexed: 11/12/2022] Open
Abstract
The myristoylated zeta inhibitory peptide (ZIP), which was originally developed as a protein kinase C/Mζ (PKCζ/PKMζ) inhibitor, is known to produce the loss of different forms of memories. However, ZIP induces memory loss even in the absence of PKMζ, and its mechanism of action, therefore, remains elusive. Here, through a kinome-wide screen, we found that glycogen synthase kinase 3 beta (GSK-3β) was robustly activated by ZIP in vitro. ZIP induced depotentiation (a cellular substrate of memory erasure) of conditioning-induced potentiation at LA synapses, and the ZIP-induced depotentiation was prevented by a GSK-3β inhibitor, 6-bromoindirubin-3-acetoxime (BIO-acetoxime). Consistently, GSK-3β inhibition by BIO-acetoxime infusion or GSK-3β knockdown by GSK-3β shRNA in the LA attenuated ZIP-induced disruption of learned fear. Furthermore, conditioned fear was decreased by expression of a non-inhibitable form of GSK-3β in the LA. Our findings suggest that GSK-3β activation is a critical step for ZIP-induced disruption of memory.
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Affiliation(s)
- Sukwoon Song
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea
| | - Jihye Kim
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea
| | - Kyungjoon Park
- Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, MA, 02478, USA
| | - Junghwa Lee
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea
| | - Sewon Park
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea
| | - Sukwon Lee
- Department of Neural Development and Disease, Korea Brain Research Institute, Daegu, Republic of Korea
| | - Jeongyeon Kim
- Department of Neural Development and Disease, Korea Brain Research Institute, Daegu, Republic of Korea
| | - Ingie Hong
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Beomjong Song
- International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo Institutes for Advanced Study (UTIAS), The University of Tokyo, Tokyo, Japan.
| | - Sukwoo Choi
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea.
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28
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Neurotrophin signalling in amygdala-dependent cued fear learning. Cell Tissue Res 2020; 382:161-172. [PMID: 32845430 PMCID: PMC7529623 DOI: 10.1007/s00441-020-03260-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 07/13/2020] [Indexed: 12/20/2022]
Abstract
The amygdala is a central hub for fear learning assessed by Pavlovian fear conditioning. Indeed, the prevailing hypothesis that learning and memory are mediated by changes in synaptic strength was shown most convincingly at thalamic and cortical afferents to the lateral amygdala. The neurotrophin brain-derived neurotrophic factor (BDNF) is known to regulate synaptic plasticity and memory formation in many areas of the mammalian brain including the amygdala, where BDNF signalling via tropomyosin-related kinase B (TrkB) receptors is prominently involved in fear learning. This review updates the current understanding of BDNF/TrkB signalling in the amygdala related to fear learning and extinction. In addition, actions of proBDNF/p75NTR and NGF/TrkA as well as NT-3/TrkC signalling in the amygdala are introduced.
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29
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Lin CC, Chen TY, Cheng PY, Liu YP. Early life social experience affects adulthood fear extinction deficit and associated dopamine profile abnormalities in a rat model of PTSD. Prog Neuropsychopharmacol Biol Psychiatry 2020; 101:109914. [PMID: 32165120 DOI: 10.1016/j.pnpbp.2020.109914] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 02/13/2020] [Accepted: 03/06/2020] [Indexed: 12/20/2022]
Abstract
Individuals may develop fear extinction deficits after life-threatening traumatic events; such deficits indicate posttraumatic stress disorder (PTSD). Because the occurrence of this disorder differs among people who have experienced trauma, hidden underlying factors should be determined. Increasing evidence suggests the involvement of neuronal dysregulation of information processes or cognitive function during development. This neuronal dysregulation is caused by disturbances in dopamine (DA) transmission within the fear circuit, which comprises the medial prefrontal cortex (mPFC), amygdala, and hippocampus. Single prolonged stress (SPS) combined with an isolation rearing (IR) paradigm was used to randomly assign rats to four groups [social rearing-no SPS (SR-NS), SR-SPS, IR-NS, and IR-SPS], and their performance in prepulse inhibition (PPI) and on Pavlovian fear conditioning tests was assessed. Tissue DA levels and the expression of DA receptors (D1R and D2R) in the fear circuit were measured at the end of the experiment. Our results indicated that PPI deficits and fear extinction problems were specific to rats subjected to IR and SPS, respectively. Furthermore, IR-induced PPI deficits were not influenced by SPS, but SPS-induced fear extinction retrieval impairment could be adjusted according to previous IR experiences. Neurochemically, tissue DA levels and D1R expression in the mPFC and amygdala were nonspecifically reduced by IR and SPS, whereas D2R expression in the mPFC and amygdala was higher in IR-SPS than in SR-SPS rats. These findings suggest that early life experiences may influence fear responses in adulthood through a change in DA profiles within the fear circuit.
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Affiliation(s)
- Chen-Cheng Lin
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 11490, Taiwan; Department of Psychiatry, Cheng Hsin General Hospital, Taipei 11220, Taiwan; Laboratory of Cognitive Neuroscience, Department of Physiology, National Defense Medical Center, Taipei 11490, Taiwan
| | - Tzung-Yan Chen
- Department of Psychiatry, Cheng Hsin General Hospital, Taipei 11220, Taiwan; Laboratory of Cognitive Neuroscience, Department of Physiology, National Defense Medical Center, Taipei 11490, Taiwan
| | - Pao-Yun Cheng
- Department of Physiology, National Defense Medical Center, Taipei 11490, Taiwan.
| | - Yia-Ping Liu
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 11490, Taiwan; Department of Psychiatry, Cheng Hsin General Hospital, Taipei 11220, Taiwan; Laboratory of Cognitive Neuroscience, Department of Physiology, National Defense Medical Center, Taipei 11490, Taiwan.
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30
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Lay BPP, Pitaru AA, Boulianne N, Esber GR, Iordanova MD. Different methods of fear reduction are supported by distinct cortical substrates. eLife 2020; 9:e55294. [PMID: 32589138 PMCID: PMC7343386 DOI: 10.7554/elife.55294] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 06/25/2020] [Indexed: 12/13/2022] Open
Abstract
Understanding how learned fear can be reduced is at the heart of treatments for anxiety disorders. Tremendous progress has been made in this regard through extinction training in which the aversive outcome is omitted. However, current progress almost entirely rests on this single paradigm, resulting in a very specialized knowledgebase at the behavioural and neural level of analysis. Here, we used a dual-paradigm approach to show that different methods that lead to reduction in learned fear in rats are dissociated in the cortex. We report that the infralimbic cortex has a very specific role in fear reduction that depends on the omission of aversive events but not on overexpectation. The orbitofrontal cortex, a structure generally overlooked in fear, is critical for downregulating fear when novel predictions about upcoming aversive events are generated, such as when fear is inflated or overexpected, but less so when an expected aversive event is omitted.
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Affiliation(s)
- Belinda PP Lay
- Center for Studies in Behavioural Neurobiology, Department of Psychology, Concordia UniversityMontrealCanada
| | - Audrey A Pitaru
- Center for Studies in Behavioural Neurobiology, Department of Psychology, Concordia UniversityMontrealCanada
| | - Nathan Boulianne
- Center for Studies in Behavioural Neurobiology, Department of Psychology, Concordia UniversityMontrealCanada
| | - Guillem R Esber
- Department of Psychology, Brooklyn College of the City University of New YorkBrooklynUnited States
| | - Mihaela D Iordanova
- Center for Studies in Behavioural Neurobiology, Department of Psychology, Concordia UniversityMontrealCanada
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31
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Rich MT, Huang YH, Torregrossa MM. Plasticity at Thalamo-amygdala Synapses Regulates Cocaine-Cue Memory Formation and Extinction. Cell Rep 2020; 26:1010-1020.e5. [PMID: 30673597 DOI: 10.1016/j.celrep.2018.12.105] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 11/27/2018] [Accepted: 12/26/2018] [Indexed: 01/02/2023] Open
Abstract
Repeated drug use has long-lasting effects on plasticity throughout the brain's reward and memory systems. Environmental cues that are associated with drugs of abuse can elicit craving and relapse, but the neural circuits responsible for driving drug-cue-related behaviors have not been well delineated, creating a hurdle for the development of effective relapse prevention therapies. In this study, we used a cocaine+cue self-administration paradigm followed by cue re-exposure to establish that the strength of the drug cue association corresponds to the strength of synapses between the medial geniculate nucleus (MGN) of the thalamus and the lateral amygdala (LA). Furthermore, we demonstrate, via optogenetically induced LTD of MGN-LA synapses, that reversing cocaine-induced potentiation of this pathway is sufficient to inhibit cue-induced relapse-like behavior.
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Affiliation(s)
- Matthew T Rich
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA; Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Yanhua H Huang
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Mary M Torregrossa
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA.
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32
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Antov MI, Plog E, Bierwirth P, Keil A, Stockhorst U. Visuocortical tuning to a threat-related feature persists after extinction and consolidation of conditioned fear. Sci Rep 2020; 10:3926. [PMID: 32127551 PMCID: PMC7054355 DOI: 10.1038/s41598-020-60597-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 02/14/2020] [Indexed: 12/28/2022] Open
Abstract
Neurons in the visual cortex sharpen their orientation tuning as humans learn aversive contingencies. A stimulus orientation (CS+) that reliably predicts an aversive noise (unconditioned stimulus: US) is selectively enhanced in lower-tier visual cortex, while similar unpaired orientations (CS-) are inhibited. Here, we examine in male volunteers how sharpened visual processing is affected by fear extinction learning (where no US is presented), and how fear and extinction memory undergo consolidation one day after the original learning episode. Using steady-state visually evoked potentials from electroencephalography in a fear generalization task, we found that extinction learning prompted rapid changes in orientation tuning: Both conditioned visuocortical and skin conductance responses to the CS+ were strongly reduced. Next-day re-testing (delayed recall) revealed a brief but precise return-of-tuning to the CS+ in visual cortex accompanied by a brief, more generalized return-of-fear in skin conductance. Explorative analyses also showed persistent tuning to the threat cue in higher visual areas, 24 h after successful extinction, outlasting peripheral responding. Together, experience-based changes in the sensitivity of visual neurons show response patterns consistent with memory consolidation and spontaneous recovery, the hallmarks of long-term neural plasticity.
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Affiliation(s)
- Martin I Antov
- Institute of Psychology, Experimental Psychology II and Biological Psychology, University of Osnabrück, D-49074, Osnabrück, Germany.
| | - Elena Plog
- Institute of Psychology, Experimental Psychology II and Biological Psychology, University of Osnabrück, D-49074, Osnabrück, Germany
| | - Philipp Bierwirth
- Institute of Psychology, Experimental Psychology II and Biological Psychology, University of Osnabrück, D-49074, Osnabrück, Germany
| | - Andreas Keil
- Department of Psychology and Center for the Study of Emotion and Attention, University of Florida, Gainesville, Florida, 32611, USA
| | - Ursula Stockhorst
- Institute of Psychology, Experimental Psychology II and Biological Psychology, University of Osnabrück, D-49074, Osnabrück, Germany
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33
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Song S, Lee J, Park S, Choi S. Fear renewal requires nitric oxide signaling in the lateral amygdala. Biochem Biophys Res Commun 2020; 523:86-90. [PMID: 31831176 DOI: 10.1016/j.bbrc.2019.12.038] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 12/06/2019] [Indexed: 11/28/2022]
Abstract
Fear renewal is defined as return of the conditioned fear responses after extinction when a conditioned stimulus (CS) is given outside of the extinction context. Previously, we have suggested that extinction induces S-nitrosylation of GluA1 in the lateral amygdala (LA), and that the extinction-induced S-nitrosylation of GluA1 lowers the threshold of GluA1 phosphorylation (at Ser 831) which is required for fear renewal. This fits nicely with the fact that fear renewal is induced by weak stimuli. However, it has not been tested whether S-nitrosylation of GluA1 in the LA is indeed required for fear renewal. In the present study, we used three different chemicals to impede protein S-nitrosylation via distinct mechanisms. Fear renewal was inhibited by microinjection of 7-Nitroindazole (nNOS inhibitor), and ZL006 (a blocker of PSD-95-nNOS interaction) before fear renewal. Furthermore, fear renewal was also attenuated by microinjection of a strong antioxidant (N-acetyl cysteine), which scavenges reactive oxygen including nitric oxide, into the LA before each extinction training. These findings suggest that protein S-nitrosylation is required for fear renewal.
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Affiliation(s)
- Sukwoon Song
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea.
| | - Junghwa Lee
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Sewon Park
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Sukwoo Choi
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea.
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34
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Sangha S, Diehl MM, Bergstrom HC, Drew MR. Know safety, no fear. Neurosci Biobehav Rev 2020; 108:218-230. [PMID: 31738952 PMCID: PMC6981293 DOI: 10.1016/j.neubiorev.2019.11.006] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 09/27/2019] [Accepted: 11/11/2019] [Indexed: 02/08/2023]
Abstract
Every day we are bombarded by stimuli that must be assessed for their potential for harm or benefit. Once a stimulus is learned to predict harm, it can elicit fear responses. Such learning can last a lifetime but is not always beneficial for an organism. For an organism to thrive in its environment, it must know when to engage in defensive, avoidance behaviors and when to engage in non-defensive, approach behaviors. Fear should be suppressed in situations that are not dangerous: when a novel, innocuous stimulus resembles a feared stimulus, when a feared stimulus no longer predicts harm, or when there is an option to avoid harm. A cardinal feature of anxiety disorders is the inability to suppress fear adaptively. In PTSD, for instance, learned fear is expressed inappropriately in safe situations and is resistant to extinction. In this review, we discuss mechanisms of suppressing fear responses during stimulus discrimination, fear extinction, and active avoidance, focusing on the well-studied tripartite circuit consisting of the amygdala, medial prefrontal cortex and hippocampus.
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Affiliation(s)
- Susan Sangha
- Department of Psychological Sciences and Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, USA.
| | - Maria M Diehl
- Department of Psychological Sciences, Kansas State University, Manhattan, KS, USA.
| | - Hadley C Bergstrom
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, NY, USA.
| | - Michael R Drew
- Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Austin, TX, USA.
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35
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KIDA S. Function and mechanisms of memory destabilization and reconsolidation after retrieval. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2020; 96:95-106. [PMID: 32161213 PMCID: PMC7167366 DOI: 10.2183/pjab.96.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 12/27/2019] [Indexed: 05/30/2023]
Abstract
Memory retrieval is not a passive process. When a memory is retrieved, the retrieved memory is destabilized, similar to short-term memory just after learning, and requires memory reconsolidation to re-stabilize the memory. Recent studies characterizing destabilization and reconsolidation showed that a retrieved memory is not always destabilized and that there are boundary conditions that determine the induction of destabilization and reconsolidation according to certain parameters, such as the duration of retrieval and the memory strength and age. Moreover, the reconsolidation of contextual fear memory is not independent of memory extinction; rather, these memory processes interact with each other. There is an increasing number of findings suggesting that destabilization following retrieval facilitates the modification, weakening, or strengthening of the original memory, and the resultant updated memory is stabilized through reconsolidation. Reconsolidation could be targeted therapeutically to improve emotional disorders such as post-traumatic stress disorder and phobia. Thus, this review summarizes recent findings to understand the mechanisms and function of reconsolidation.
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Affiliation(s)
- Satoshi KIDA
- Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
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36
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Milton AL. Fear not: recent advances in understanding the neural basis of fear memories and implications for treatment development. F1000Res 2019; 8:F1000 Faculty Rev-1948. [PMID: 31824654 PMCID: PMC6880271 DOI: 10.12688/f1000research.20053.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/13/2019] [Indexed: 01/01/2023] Open
Abstract
Fear is a highly adaptive emotion that has evolved to promote survival and reproductive fitness. However, maladaptive expression of fear can lead to debilitating stressor-related and anxiety disorders such as post-traumatic stress disorder. Although the neural basis of fear has been extensively researched for several decades, recent technological advances in pharmacogenetics and optogenetics have allowed greater resolution in understanding the neural circuits that underlie fear. Alongside conceptual advances in the understanding of fear memory, this increased knowledge has clarified mechanisms for some currently available therapies for post-traumatic stress disorder and has identified new potential treatment targets.
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Affiliation(s)
- Amy L. Milton
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK
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37
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Zhao J, Ying L, Liu Y, Liu N, Tu G, Zhu M, Wu Y, Xiao B, Ye L, Li J, Guo F, Zhang L, Wang H, Zhang L. Different roles of Rac1 in the acquisition and extinction of methamphetamine-associated contextual memory in the nucleus accumbens. Am J Cancer Res 2019; 9:7051-7071. [PMID: 31660086 PMCID: PMC6815963 DOI: 10.7150/thno.34655] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 07/30/2019] [Indexed: 02/03/2023] Open
Abstract
Rationale: Repeated methamphetamine (METH) exposure induces long-term cognitive deficits and pathological drug-associated memory that can be disrupted by manipulating memory reconsolidation and extinction. The nucleus accumbens (NAc) is the key region of the brain reward system and predominantly consists of two subtypes of medium spiny neurons (MSNs) based on the expression of D1 or D2 dopamine receptors (D1-MSNs or D2-MSNs). Spine structural plasticity in the NAc is critical for the acquisition, reconsolidation and extinction of drug-associated memory. However, the molecular mechanisms underlying METH-associated memory and spine remodelling in each type of MSNs in the NAc remain unknown. Here, we explored whether Rac1 in the NAc mediates METH-associated contextual memory and spine remodelling. Methods: Pharmacological and genetic manipulations of Rac1 were used to investigate its role during the acquisition, reconsolidation and extinction of METH-associated contextual memory. Recombinant adeno-associated viruses expressing mCherry under the control of the dopamine D1 receptor gene promoter (Drd1-mCherry) or dopamine D2 receptor gene promoter (Drd2-mCherry) were used to specifically label D1-MSNs or D2-MSNs. Results: Using viral-mediated gene transfer, we demonstrated that decreased Rac1 activity was required for the acquisition of METH-associated contextual memory and the METH-induced increase in thin spine density, whereas increased Rac1 signalling was important for the extinction of METH-associated contextual memory and the related elimination of thin spines. Moreover, the increase of dendritic spines was both found in D1-MSNs and D2-MSNs during the acquisition process, but extinction training selectively decreased the spine density in D1-MSNs. Interestingly, Rac1 was responsible for METH-induced spine plasticity in D1-MSNs but not in D2-MSNs. Additionally, we found that microinjection of a Rac1 inhibitor or activator into the NAc was not sufficient to disrupt reconsolidation, and the pharmacological activation of Rac1 in the NAc facilitated the extinction of METH-associated contextual memory. Regarding cognitive memory, decreased Rac1 activity improved the METH-induced impairment in object recognition memory. Conclusion: Our findings indicate that Rac1 plays opposing roles in the acquisition and extinction of METH-associated contextual memory and reveal the cell-specific role of Rac1 in METH-associated spine remodelling, suggesting that Rac1 is a potential therapeutic target for reducing relapse in METH addiction and remediating METH-induced recognition memory impairment.
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Cazares VA, Rodriguez G, Parent R, Ouillette L, Glanowska KM, Moore SJ, Murphy GG. Environmental variables that ameliorate extinction learning deficits in the 129S1/SvlmJ mouse strain. GENES BRAIN AND BEHAVIOR 2019; 18:e12575. [PMID: 30973205 DOI: 10.1111/gbb.12575] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 03/28/2019] [Accepted: 04/09/2019] [Indexed: 10/27/2022]
Abstract
Fear conditioning is an associative learning process by which organisms learn to avoid environmental stimuli that are predictive of aversive outcomes. Fear extinction learning is a process by which avoidance of fear-conditioned stimuli is attenuated when the environmental stimuli is no longer predictive of the aversive outcome. Aberrant fear conditioning and extinction learning are key elements in the development of several anxiety disorders. The 129S1 inbred strain of mice is used as an animal model for maladaptive fear learning because this strain has been shown to generalize fear to other nonaversive stimuli and is less capable of extinguishing fear responses relative to other mouse strains, such as the C57BL/6. Here we report new environmental manipulations that enhance fear and extinction learning, including the ability to discriminate between an aversively paired tone and a neutral tone, in both the 129S1 and C57BL/6 strains of mice. Specifically, we show that discontinuous ("pipped") tone stimuli significantly enhance within-session extinction learning and the discrimination between neutral and aversively paired stimuli in both strains. Furthermore, we find that extinction training in novel contexts significantly enhances the consolidation and recall of extinction learning for both strains. Cumulatively, these results underscore how environmental changes can be leveraged to ameliorate maladaptive learning in animal models and may advance cognitive and behavioral therapeutic strategies.
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Affiliation(s)
- Victor A Cazares
- Department of Molecular and Integrative Physiology and Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan
| | - Genesis Rodriguez
- Department of Molecular and Integrative Physiology and Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan
| | - Rachel Parent
- Department of Molecular and Integrative Physiology and Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan
| | - Lara Ouillette
- Department of Molecular and Integrative Physiology and Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan
| | | | - Shannon J Moore
- Department of Molecular and Integrative Physiology and Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan
| | - Geoffrey G Murphy
- Department of Molecular and Integrative Physiology and Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan
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Transient inactivation of the visual-associative nidopallium frontolaterale (NFL) impairs extinction learning and context encoding in pigeons. Neurobiol Learn Mem 2019; 158:50-59. [DOI: 10.1016/j.nlm.2019.01.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 01/07/2019] [Accepted: 01/15/2019] [Indexed: 01/01/2023]
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Kida S. Reconsolidation/destabilization, extinction and forgetting of fear memory as therapeutic targets for PTSD. Psychopharmacology (Berl) 2019; 236:49-57. [PMID: 30374892 PMCID: PMC6373183 DOI: 10.1007/s00213-018-5086-2] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 10/16/2018] [Indexed: 12/11/2022]
Abstract
Post-traumatic stress disorder (PTSD) is a psychiatric disorder associated with memories of traumatic experiences. Conditioned fear memory, a representative model of traumatic memories, is observed across species from lower to higher animals, including humans. Numerous studies have investigated the mechanisms of conditioned fear memory and have led to the identification of the underlying processes involved in fear memory regulation, including cellular and systems consolidation of fear conditioning, destabilization/reconsolidation and extinction after fear memory retrieval, and forgetting of fear memory. These studies suggested that mechanisms for fear memory regulation are shared by humans and other higher animals. Additionally, rodent studies have identified the mechanisms of fear memory at the molecular, cellular, and circuit levels. Findings from these studies in rodents have been applied to facilitate the development and improvement of PTSD intervention. For instance, reconsolidation and extinction of fear memories have been applied for PTSD treatment to improve prolonged exposure (PE) therapy, an effective psychotherapy for PTSD. Combination of medications weakening retrieved traumatic memory (e.g., by facilitating both destabilization and extinction) with PE therapy may contribute to improvement of PTSD. Interestingly, a recent study in mice identified forgetting of fear memory as another potential therapeutic target for PTSD. A better understanding of the mechanisms involved in fear memory processes is likely to facilitate the development of better treatments for PTSD. This review describes fear memory processes and their mechanisms and discusses the pros and cons of applying how this knowledge can be applied in the development of interventions for PTSD.
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Grants
- 15H02488, 18H03944, 23300120, 20380078, 24650172, 26640014, 17K19464, 24116008, 24116001, 23115716, 17H06084, 17H05961, 17H05581, 18H05428, 18022038, 22022039 KAKENHI
- - Core Research for Evolutional Science and Technology
- - The Science Research Promotion Fund, The Promotion and Mutual Aid Corporation for Private Schools of Japan
- - Sumitomo Foundation
- - Naito Foundation
- - Uehara Memorial Foundation
- - Takeda Science Foundation
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Affiliation(s)
- Satoshi Kida
- Department of Bioscience, Faculty of Life Science, Tokyo University of Agriculture, Tokyo, Japan.
- Department of Bioscience, Faculty of Applied Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo, 156-8502, Japan.
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41
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Neural circuits for a top-down control of fear and extinction. Psychopharmacology (Berl) 2019; 236:313-320. [PMID: 30215217 DOI: 10.1007/s00213-018-5033-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 09/06/2018] [Indexed: 12/28/2022]
Abstract
Fear learning and extinction are controlled by the activity of three interconnected regions: the amygdala, hippocampus, and prefrontal cortex. Of these, the medial prefrontal cortex modulates specific aspects in fear and extinction via a top-down regulation. In recent years, extensive progress has been made in our understanding of the neural circuits that mediate fear-related behaviors and their modulation by ascending systems. The development of new experimental techniques is now revealing the details of the intrinsic circuits within these structures as well as the connections between them. Here, we highlight recent advances in our understanding of how the prefrontal cortex may mediate such a top-down regulation.
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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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Marshall PR, Bredy TW. Neuroepigenetic mechanisms underlying fear extinction: emerging concepts. Psychopharmacology (Berl) 2019; 236:133-142. [PMID: 30506235 PMCID: PMC7293886 DOI: 10.1007/s00213-018-5084-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 10/16/2018] [Indexed: 12/11/2022]
Abstract
An understanding of how memory is acquired and how it can be modified in fear-related anxiety disorders, with the enhancement of failing memories on one side and a reduction or elimination of traumatic memories on the other, is a key unmet challenge in the fields of neuroscience and neuropsychiatry. The latter process depends on an important form of learning called fear extinction, where a previously acquired fear-related memory is decoupled from its ability to control behaviour through repeated non-reinforced exposure to the original fear-inducing cue. Although simple in description, fear extinction relies on a complex pattern of brain region and cell-type specific processes, some of which are unique to this form of learning and, for better or worse, contribute to the inherent instability of fear extinction memory. Here, we explore an emerging layer of biology that may compliment and enrich the synapse-centric perspective of fear extinction. As opposed to the more classically defined role of protein synthesis in the formation of fear extinction memory, a neuroepigenetic view of the experience-dependent gene expression involves an appreciation of dynamic changes in the state of the entire cell: from a transient change in plasticity at the level of the synapse, to potentially more persistent long-term effects within the nucleus. A deeper understanding of neuroepigenetic mechanisms and how they influence the formation and maintenance of fear extinction memory has the potential to enable the development of more effective treatment approaches for fear-related neuropsychiatric conditions.
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Affiliation(s)
- Paul R Marshall
- Cognitive Neuroepigenetics Laboratory, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia.
| | - Timothy W Bredy
- Cognitive Neuroepigenetics Laboratory, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
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Fear extinction reverses dendritic spine formation induced by fear conditioning in the mouse auditory cortex. Proc Natl Acad Sci U S A 2018; 115:9306-9311. [PMID: 30150391 DOI: 10.1073/pnas.1801504115] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Fear conditioning-induced behavioral responses can be extinguished after fear extinction. While fear extinction is generally thought to be a form of new learning, several lines of evidence suggest that neuronal changes associated with fear conditioning could be reversed after fear extinction. To better understand how fear conditioning and extinction modify synaptic circuits, we examined changes of postsynaptic dendritic spines of layer V pyramidal neurons in the mouse auditory cortex over time using transcranial two-photon microscopy. We found that auditory-cued fear conditioning induced the formation of new dendritic spines within 2 days. The survived new spines induced by fear conditioning with one auditory cue were clustered within dendritic branch segments and spatially segregated from new spines induced by fear conditioning with a different auditory cue. Importantly, fear extinction preferentially caused the elimination of newly formed spines induced by fear conditioning in an auditory cue-specific manner. Furthermore, after fear extinction, fear reconditioning induced reformation of new dendritic spines in close proximity to the sites of new spine formation induced by previous fear conditioning. These results show that fear conditioning, extinction, and reconditioning induce cue- and location-specific dendritic spine remodeling in the auditory cortex. They also suggest that changes of synaptic connections induced by fear conditioning are reversed after fear extinction.
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45
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Siucinska E, Brutkowski W, Bernas T. CB1 Cannabinoid Receptor Expression in the Barrel Field Region Is Associated with Mouse Learning. ACS Chem Neurosci 2018. [PMID: 29537813 DOI: 10.1021/acschemneuro.7b00500] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
We found previously that fear conditioning by combined stimulation of a row B facial vibrissae (conditioned stimulus, CS) with a tail shock (unconditioned stimulus, UCS) leads to expansion of the cortical representation of the "trained" row, labeled with 2-deoxyglucose (2DG), in the layer IIIb/IV of the adult mouse the primary somatosensory cortex (S1) 24 h later. We have observed that these learning-dependent plastic changes are manifested by increased expression of somatostatin, cholecystokinin (SST+, CCK+) but not parvalbumin (PV+) immunopositive interneurons We have expanded this research and quantified a numerical value of CB1-expressing and PV-expressing GABAergic axon terminals (CB1+ and PV+ immunopositive puncta) that innervate different segments of postsynaptic cells in the barrel hollows of S1 cortex. We used 3D microscopy to identify the CB+ and PV+ puncta in the barrel cortex "trained" and the control hemispheres CS+UCS group and in controls: Pseudoconditioned, CS-only, UCS-only, and naive animals. We have identified that (i) the association between whisker-shock "trained" barrel B hollows and CB1+, but not PV+ puncta expression remained significant after Bonferroni correction, (ii) CS+UCS has had a significant increasing effect on expression of CB1+ but not PV+ puncta in barrel cortex "trained" hemisphere, and (iii) the pseudoconditioning had a significant decreasing effect on expression of CB1+, but not on PV+ puncta in barrel cortex, both trained and untrained hemispheres. It is correlated to disturbing behaviors. The results suggest that CB1+ puncta regulation is specifically linked with mechanisms leading to learning-dependent plasticity in S1 cortex.
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Affiliation(s)
- Ewa Siucinska
- Laboratory of Neuroplasticity, Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Str., 02-093 Warsaw, Poland
| | - Wojciech Brutkowski
- Laboratory of Imaging Tissue Structure and Function Neurobiology Center, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Str., 02-093 Warsaw, Poland
| | - Tytus Bernas
- Laboratory of Imaging Tissue Structure and Function Neurobiology Center, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Str., 02-093 Warsaw, Poland
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Grunfeld IS, Likhtik E. Mixed selectivity encoding and action selection in the prefrontal cortex during threat assessment. Curr Opin Neurobiol 2018; 49:108-115. [PMID: 29454957 PMCID: PMC5889962 DOI: 10.1016/j.conb.2018.01.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 12/27/2017] [Accepted: 01/17/2018] [Indexed: 01/18/2023]
Abstract
The medial prefrontal cortex (mPFC) regulates expression of emotional behavior. The mPFC combines multivariate information from its inputs, and depending on the imminence of threat, activates downstream networks that either increase or decrease the expression of anxiety-related motor behavior and autonomic activation. Here, we selectively highlight how subcortical input to the mPFC from two example structures, the amygdala and ventral hippocampus, help shape mixed selectivity encoding and action selection during emotional processing. We outline a model where prefrontal subregions modulate behavior along orthogonal motor dimensions, and exhibit connectivity that selects for expression of one behavioral strategy while inhibiting the other.
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Affiliation(s)
- Itamar S Grunfeld
- Biology Department, Hunter College, CUNY, United States; Neuroscience Collaborative, The Graduate Center, CUNY, United States
| | - Ekaterina Likhtik
- Biology Department, Hunter College, CUNY, United States; Neuroscience Collaborative, The Graduate Center, CUNY, United States.
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Qi CC, Wang QJ, Ma XZ, Chen HC, Gao LP, Yin J, Jing YH. Interaction of basolateral amygdala, ventral hippocampus and medial prefrontal cortex regulates the consolidation and extinction of social fear. Behav Brain Funct 2018; 14:7. [PMID: 29554926 PMCID: PMC5858134 DOI: 10.1186/s12993-018-0139-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 03/14/2018] [Indexed: 11/13/2022] Open
Abstract
Background Following a social defeat, the balanced establishment and extinction of aversive information is a beneficial strategy for individual survival. Abnormal establishment or extinction is implicated in the development of mental disorders. This study investigated the time course of the establishment and extinction of aversive information from acute social defeat and the temporal responsiveness of the basolateral amygdala (BLA), ventral hippocampus (vHIP) and medial prefrontal cortex (mPFC) in this process. Methods Mouse models of acute social defeat were established by using the resident–intruder paradigm. To evaluate the engram of social defeat, the intruder mice were placed into the novel context at designated time to test the social behavior. Furthermore, responses of BLA, vHIP and mPFC were investigated by analyzing the expression of immediate early genes, such as zif268, arc, and c-fos. Results The results showed after an aggressive attack, aversive memory was maintained for approximately 7 days before gradually diminishing. The establishment and maintenance of aversive stimulation were consistently accompanied by BLA activity. By contrast, vHIP and mPFC response was inhibited from this process. Additionally, injecting muscimol (Mus), a GABA receptor agonist, into the BLA alleviated the freezing behavior and social fear and avoidance. Simultaneously, Mus treatment decreased the zif268 and arc expression in BLA, but it increased their expression in vHIP. Conclusion Our data support and extend earlier findings that implicate BLA, vHIP and mPFC in social defeat. The time courses of the establishment and extinction of social defeat are particularly consistent with the contrasting BLA and vHIP responses involved in this process.![]() Electronic supplementary material The online version of this article (10.1186/s12993-018-0139-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Chu-Chu Qi
- Institute of Anatomy and Histology & Embryology, Neuroscience, School of Basic Medical Sciences, Lanzhou University, No. 199 of Donggang West Road, Lanzhou, 730000, Gansu, People's Republic of China
| | - Qing-Jun Wang
- Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, No. 199 of Donggang West Road, Lanzhou, 730000, Gansu, People's Republic of China
| | - Xue-Zhu Ma
- Institute of Anatomy and Histology & Embryology, Neuroscience, School of Basic Medical Sciences, Lanzhou University, No. 199 of Donggang West Road, Lanzhou, 730000, Gansu, People's Republic of China
| | - Hai-Chao Chen
- Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, No. 199 of Donggang West Road, Lanzhou, 730000, Gansu, People's Republic of China
| | - Li-Ping Gao
- Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, No. 199 of Donggang West Road, Lanzhou, 730000, Gansu, People's Republic of China
| | - Jie Yin
- Institute of Anatomy and Histology & Embryology, Neuroscience, School of Basic Medical Sciences, Lanzhou University, No. 199 of Donggang West Road, Lanzhou, 730000, Gansu, People's Republic of China
| | - Yu-Hong Jing
- Institute of Anatomy and Histology & Embryology, Neuroscience, School of Basic Medical Sciences, Lanzhou University, No. 199 of Donggang West Road, Lanzhou, 730000, Gansu, People's Republic of China. .,Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Lanzhou University, No. 199 of Donggang West Road, Lanzhou, 730000, Gansu, People's Republic of China.
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An X, Yang P, Chen S, Zhang F, Yu D. An Additional Prior Retrieval Alters the Effects of a Retrieval-Extinction Procedure on Recent and Remote Fear Memory. Front Behav Neurosci 2018; 11:259. [PMID: 29358910 PMCID: PMC5766663 DOI: 10.3389/fnbeh.2017.00259] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Accepted: 12/19/2017] [Indexed: 11/19/2022] Open
Abstract
Several studies have shown that the isolated retrieval of a consolidated fear memory can induce a labile phase, during which extinction training can prevent the reinstatement, a form of relapse in which fear response to a fear-provoking context returns when a mild shock is presented. However, fear memory retrieval may also have another opposing result: the enhancement of fear memory. This implies that the fear memory trace can be modified by a brief retrieval. Unclear is whether the fear-impairing effect of retrieval-extinction (RE) is altered by a prior brief retrieval. The present study investigated the responses of recent and remote fear memories to the RE procedure after the presentation of an additional prior retrieval (priRet). We found that a single RE procedure effectively blocked the reinstatement of 2-day recent contextual fear memory. The memory-impairing effect of the RE procedure on recent fear was not observed when priRet was presented 6 or 24 h before the RE procedure. In contrast to the 2-day recent memory, the RE procedure failed to block the reinstatement of 36-day remote fear memory but successfully disrupted the return of remote fear memory after priRet. This memory-disruptive effect on remote memory did not occur when priRet was performed in a novel context. Nimodipine administration revealed that the blockade of priRet-induced processes recovered the effects of the RE procedure on both recent and remote fear memories. Our findings suggest that the susceptibility of recent and remote fear memories to RE procedures can be altered by an additional retrieval.
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Affiliation(s)
- Xianli An
- School of Educational Science, Yangzhou University, Yangzhou, China.,Jiangsu Key Laboratory of Experimental and Translational Non-coding RNA Research, School of Medicine, Yangzhou University, Yangzhou, China
| | - Ping Yang
- School of Educational Science, Yangzhou University, Yangzhou, China
| | - Siguang Chen
- School of Educational Science, Yangzhou University, Yangzhou, China
| | - Fenfen Zhang
- School of Educational Science, Yangzhou University, Yangzhou, China
| | - Duonan Yu
- Jiangsu Key Laboratory of Experimental and Translational Non-coding RNA Research, School of Medicine, Yangzhou University, Yangzhou, China.,RNA Center, Institute of Comparative Medicine, Yangzhou University, Yangzhou, China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonosis, Yangzhou, China
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