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Abatis M, Perin R, Niu R, van den Burg E, Hegoburu C, Kim R, Okamura M, Bito H, Markram H, Stoop R. Fear learning induces synaptic potentiation between engram neurons in the rat lateral amygdala. Nat Neurosci 2024:10.1038/s41593-024-01676-6. [PMID: 38871992 DOI: 10.1038/s41593-024-01676-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 05/07/2024] [Indexed: 06/15/2024]
Abstract
The lateral amygdala (LA) encodes fear memories by potentiating sensory inputs associated with threats and, in the process, recruits 10-30% of its neurons per fear memory engram. However, how the local network within the LA processes this information and whether it also plays a role in storing it are still largely unknown. Here, using ex vivo 12-patch-clamp and in vivo 32-electrode electrophysiological recordings in the LA of fear-conditioned rats, in combination with activity-dependent fluorescent and optogenetic tagging and recall, we identified a sparsely connected network between principal LA neurons that is organized in clusters. Fear conditioning specifically causes potentiation of synaptic connections between learning-recruited neurons. These findings of synaptic plasticity in an autoassociative excitatory network of the LA may suggest a basic principle through which a small number of pyramidal neurons could encode a large number of memories.
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Affiliation(s)
- Marios Abatis
- Department of Psychiatry, Center for Psychiatric Neuroscience, University Hospital of Lausanne, Prilly-Lausanne, Switzerland
| | - Rodrigo Perin
- Brain-Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Ruifang Niu
- Department of Psychiatry, Center for Psychiatric Neuroscience, University Hospital of Lausanne, Prilly-Lausanne, Switzerland
| | - Erwin van den Burg
- Department of Psychiatry, Center for Psychiatric Neuroscience, University Hospital of Lausanne, Prilly-Lausanne, Switzerland
| | - Chloe Hegoburu
- Department of Psychiatry, Center for Psychiatric Neuroscience, University Hospital of Lausanne, Prilly-Lausanne, Switzerland
| | - Ryang Kim
- Department of Neurochemistry, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Michiko Okamura
- Department of Neurochemistry, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Haruhiko Bito
- Department of Neurochemistry, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Henry Markram
- Brain-Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Ron Stoop
- Department of Psychiatry, Center for Psychiatric Neuroscience, University Hospital of Lausanne, Prilly-Lausanne, Switzerland.
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2
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Grabenhorst F, Ponce-Alvarez A, Battaglia-Mayer A, Deco G, Schultz W. A view-based decision mechanism for rewards in the primate amygdala. Neuron 2023; 111:3871-3884.e14. [PMID: 37725980 PMCID: PMC10914681 DOI: 10.1016/j.neuron.2023.08.024] [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: 08/15/2022] [Revised: 07/12/2023] [Accepted: 08/23/2023] [Indexed: 09/21/2023]
Abstract
Primates make decisions visually by shifting their view from one object to the next, comparing values between objects, and choosing the best reward, even before acting. Here, we show that when monkeys make value-guided choices, amygdala neurons encode their decisions in an abstract, purely internal representation defined by the monkey's current view but not by specific object or reward properties. Across amygdala subdivisions, recorded activity patterns evolved gradually from an object-specific value code to a transient, object-independent code in which currently viewed and last-viewed objects competed to reflect the emerging view-based choice. Using neural-network modeling, we identified a sequence of computations by which amygdala neurons implemented view-based decision making and eventually recovered the chosen object's identity when the monkeys acted on their choice. These findings reveal a neural mechanism in the amygdala that derives object choices from abstract, view-based computations, suggesting an efficient solution for decision problems with many objects.
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Affiliation(s)
- Fabian Grabenhorst
- Department of Experimental Psychology, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK; Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK.
| | - Adrián Ponce-Alvarez
- Center for Brain and Cognition, Department of Technology and Information, Universitat Pompeu Fabra, Carrer Ramón Trias Fargas, 25-27, 08005 Barcelona, Spain; Departament de Matemàtiques, EPSEB, Universitat Politècnica de Catalunya, Barcelona, 08028 Barcelona, Spain
| | | | - Gustavo Deco
- Center for Brain and Cognition, Department of Technology and Information, Universitat Pompeu Fabra, Carrer Ramón Trias Fargas, 25-27, 08005 Barcelona, Spain; Institució Catalana de la Recerca i Estudis Avançats, Universitat Barcelona, Passeig Lluís Companys 23, 08010 Barcelona, Spain
| | - Wolfram Schultz
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
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3
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Bell BJ, Wang AA, Kim DW, Xiong J, Blackshaw S, Wu MN. Characterization of mWake expression in the murine brain. J Comp Neurol 2020; 529:1954-1987. [PMID: 33140455 DOI: 10.1002/cne.25066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 10/21/2020] [Accepted: 10/23/2020] [Indexed: 01/24/2023]
Abstract
Structure-function analyses of the mammalian brain have historically relied on anatomically-based approaches. In these investigations, physical, chemical, or electrolytic lesions of anatomical structures are applied, and the resulting behavioral or physiological responses assayed. An alternative approach is to focus on the expression pattern of a molecule whose function has been characterized and then use genetic intersectional methods to optogenetically or chemogenetically manipulate distinct circuits. We previously identified WIDE AWAKE (WAKE) in Drosophila, a clock output molecule that mediates the temporal regulation of sleep onset and sleep maintenance. More recently, we have studied the mouse homolog, mWAKE/ANKFN1, and our data suggest that its basic role in the circadian regulation of arousal is conserved. Here, we perform a systematic analysis of the expression pattern of mWake mRNA, protein, and cells throughout the adult mouse brain. We find that mWAKE labels neurons in a restricted, but distributed manner, in multiple regions of the hypothalamus (including the suprachiasmatic nucleus, dorsomedial hypothalamus, and tuberomammillary nucleus region), the limbic system, sensory processing nuclei, and additional specific brainstem, subcortical, and cortical areas. Interestingly, mWAKE is also observed in non-neuronal ependymal cells. In addition, to describe the molecular identities and clustering of mWake+ cells, we provide detailed analyses of single cell RNA sequencing data from the hypothalamus, a region with particularly significant mWAKE expression. These findings lay the groundwork for future studies into the potential role of mWAKE+ cells in the rhythmic control of diverse behaviors and physiological processes.
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Affiliation(s)
- Benjamin J Bell
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Annette A Wang
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Dong Won Kim
- Department of Neuroscience, Johns Hopkins University, Baltimore, Maryland, USA
| | - Jiali Xiong
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University, Baltimore, Maryland, USA
| | - Seth Blackshaw
- Department of Neuroscience, Johns Hopkins University, Baltimore, Maryland, USA
| | - Mark N Wu
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Neuroscience, Johns Hopkins University, Baltimore, Maryland, USA
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4
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Cell-type-specific drug-inducible protein synthesis inhibition demonstrates that memory consolidation requires rapid neuronal translation. Nat Neurosci 2020; 23:281-292. [PMID: 31959934 PMCID: PMC7147976 DOI: 10.1038/s41593-019-0568-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 12/05/2019] [Indexed: 12/04/2022]
Abstract
New protein synthesis is known to be required for the consolidation of memories, yet existing methods to block translation lack spatiotemporal precision and cell-type specificity, preventing investigation of cell-specific contributions of protein synthesis. Here, we developed a combined knock-in mouse and chemogenetic approach for cell type-specific and drug-inducible protein synthesis inhibition (ciPSI) that enables rapid and reversible phosphorylation of eIF2α, leading to inhibition of general translation by 50% in vivo. We use ciPSI to show that targeted protein synthesis inhibition pan-neuronally and in excitatory neurons in lateral amygdala (LA) impaired long-term memory. This could be recovered with artificial chemogenetic activation of LA neurons, though at the cost of stimulus generalization. Conversely, genetically reducing phosphorylation of eIF2α in excitatory neurons in LA enhanced memory strength, but reduced memory fidelity and behavioral flexibility. Our findings provide evidence for a cell-specific translation program during consolidation of threat memories.
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5
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Johnson LR, Battle AR, Martinac B. Remembering Mechanosensitivity of NMDA Receptors. Front Cell Neurosci 2019; 13:533. [PMID: 31866826 PMCID: PMC6906178 DOI: 10.3389/fncel.2019.00533] [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: 07/27/2019] [Accepted: 11/18/2019] [Indexed: 12/14/2022] Open
Abstract
An increase in post-synaptic Ca2+ conductance through activation of the ionotropic N-methyl-D-aspartate receptor (NMDAR) and concomitant structural changes are essential for the initiation of long-term potentiation (LTP) and memory formation. Memories can be initiated by coincident events, as occurs in classical conditioning, where the NMDAR can act as a molecular coincidence detector. Binding of glutamate and glycine, together with depolarization of the postsynaptic cell membrane to remove the Mg2+ channel pore block, results in NMDAR opening for Ca2+ conductance. Accumulating evidence has implicated both force-from-lipids and protein tethering mechanisms for mechanosensory transduction in NMDAR, which has been demonstrated by both, membrane stretch and application of amphipathic molecules such as arachidonic acid (AA). The contribution of mechanosensitivity to memory formation and consolidation may be to increase activity of the NMDAR leading to facilitated memory formation. In this review we look back at the progress made toward understanding the physiological and pathological role of NMDA receptor channels in mechanobiology of the nervous system and consider these findings in like of their potential functional implications for memory formation. We examine recent studies identifying mechanisms of both NMDAR and other mechanosensitive channels and discuss functional implications including gain control of NMDA opening probability. Mechanobiology is a rapidly growing area of biology with many important implications for understanding form, function and pathology in the nervous system.
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Affiliation(s)
- Luke R Johnson
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia.,St. Vincent's Clinical School, University of New South Wales, Darlinghurst, NSW, Australia.,Division of Psychology, School of Medicine, University of Tasmania, Launceston, TAS, Australia.,Department of Psychiatry, Center for the Study of Traumatic Stress, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.,School of Biomedical Sciences, Institute of Health and Biomedical Innovation (IHBI), Queensland University of Technology, Brisbane, QLD, Australia
| | - Andrew R Battle
- School of Biomedical Sciences, Institute of Health and Biomedical Innovation (IHBI), Queensland University of Technology, Brisbane, QLD, Australia.,Prince Charles Hospital Northside Clinical Unit, School of Clinical Medicine, The University of Queensland, Brisbane, QLD, Australia.,Translational Research Institute, Woolloongabba, QLD, Australia
| | - Boris Martinac
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia.,St. Vincent's Clinical School, University of New South Wales, Darlinghurst, NSW, Australia
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6
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Campese VD, Kim IT, Hou M, Gupta S, Draus C, Kurpas B, Burke K, LeDoux JE. Chemogenetic Inhibition Reveals That Processing Relative But Not Absolute Threat Requires Basal Amygdala. J Neurosci 2019; 39:8510-8516. [PMID: 31492771 PMCID: PMC6807280 DOI: 10.1523/jneurosci.2530-18.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 08/26/2019] [Accepted: 08/28/2019] [Indexed: 11/21/2022] Open
Abstract
While our understanding of appetitive motivation has benefited immensely from the use of selective outcome devaluation tools, the same cannot be said about aversive motivation. Findings from appetitive conditioning studies have shown that basal amygdala is required for behaviors that are sensitive to updates in outcome value, but similar results in aversive motivation are difficult to interpret due to a lack of outcome specificity. The studies reported here sought to develop procedures to isolate sensory-specific processes in aversive learning and behavior and to assess the possible contribution of the basal amygdala. Post-training changes to outcome value produced commensurate changes to subsequently tested conditioned responding in male rodents. Specifically, increases in shock intensity (i.e., inflation) augmented, while repeated exposure to (i.e., habituation of) an aversive sound (klaxon-horn) reduced freezing to conditioned stimuli previously paired with these outcomes. This was extended to a discriminative procedure, in which following revaluation of one event, but not the other, responding was found to be dependent on outcome value signaled by each cue. Chemogenetic inactivation of basal amygdala impaired this discrimination between stimuli signaling differently valued outcomes, but did not affect the revaluation process itself. These findings demonstrate a contribution of the basal amygdala to aversive outcome-dependent motivational processes.SIGNIFICANCE STATEMENT The specific content of pavlovian associative learning has been well studied in appetitive motivation, where the value of different foods can be easily manipulated. This has facilitated our understanding of the neural circuits that generate different forms of motivation (i.e., sensory specific vs general). Studies of aversive learning have not produced the same degree of understanding with regard to sensory specificity due to a lack of tools for evaluating sensory-specific processes. Here we use a variant of outcome devaluation procedures with aversive stimuli to study the role of basal amygdala in discriminating between aversive stimuli conveying different degrees of threat. These findings have implications for how we study generalized threat to identify dysregulation that can contribute to generalized anxiety.
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Affiliation(s)
- Vincent D Campese
- Department of Psychology, University of Evansville, Evansville Indiana 47722,
| | - Ian T Kim
- Center for Neural Science, New York University, New York, New York 10003
| | - Mian Hou
- Center for Neural Science, New York University, New York, New York 10003
| | - Saurav Gupta
- Department of Psychology, University of Evansville, Evansville Indiana 47722
| | - Cassandra Draus
- Center for Neural Science, New York University, New York, New York 10003
| | - Botagoz Kurpas
- Department of Psychology, Kingsborough College, Brooklyn, New York 11235
| | - Kelsey Burke
- Department of Psychology, Hunter College, New York, New York 10065, and
| | - Joseph E LeDoux
- Center for Neural Science, New York University, New York, New York 10003
- Emotional Brain Institute, Nathan Kline institute for Psychiatric Research, Orangeburg New York 10962
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7
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Jacques A, Wright A, Chaaya N, Overell A, Bergstrom HC, McDonald C, Battle AR, Johnson LR. Functional Neuronal Topography: A Statistical Approach to Micro Mapping Neuronal Location. Front Neural Circuits 2018; 12:84. [PMID: 30386215 PMCID: PMC6198090 DOI: 10.3389/fncir.2018.00084] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 09/20/2018] [Indexed: 01/10/2023] Open
Abstract
In order to understand the relationship between neuronal organization and behavior, precise methods that identify and quantify functional cellular ensembles are required. This is especially true in the quest to understand the mechanisms of memory. Brain structures involved in memory formation and storage, as well as the molecular determinates of memory are well-known, however, the microanatomy of functional neuronal networks remain largely unidentified. We developed a novel approach to statistically map molecular markers in neuronal networks through quantitative topographic measurement. Brain nuclei and their subdivisions are well-defined - our approach allows for the identification of new functional micro-regions within established subdivisions. A set of analytic methods relevant for measurement of discrete neuronal data across a diverse range of brain subdivisions are presented. We provide a methodology for the measurement and quantitative comparison of functional micro-neural network activity based on immunohistochemical markers matched across individual brains using micro-binning and heat mapping within brain sub-nuclei. These techniques were applied to the measurement of different memory traces, allowing for greater understanding of the functional encoding within sub-nuclei and its behavior mediated change. These approaches can be used to understand other functional and behavioral questions, including sub-circuit organization, normal memory function and the complexities of pathology. Precise micro-mapping of functional neuronal topography provides essential data to decode network activity underlying behavior.
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Affiliation(s)
- Angela Jacques
- Translational Research Institute, Brisbane, QLD, Australia.,Institute for Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.,School of Psychology and Counseling, Queensland University of Technology, Brisbane, QLD, Australia
| | - Alison Wright
- Faculty of Health Science and Medicine, Bond University, Gold Coast, QLD, Australia
| | - Nicholas Chaaya
- Translational Research Institute, Brisbane, QLD, Australia.,Institute for Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.,School of Psychology and Counseling, Queensland University of Technology, Brisbane, QLD, Australia
| | - Anne Overell
- Translational Research Institute, Brisbane, QLD, Australia.,Institute for Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.,School of Psychology and Counseling, Queensland University of Technology, Brisbane, QLD, Australia
| | - Hadley C Bergstrom
- Psychological Science Department, Vassar College, Poughkeepsie, NY, United States
| | - Craig McDonald
- Department of Psychology, George Mason University, Fairfax, VA, United States
| | - Andrew R Battle
- Translational Research Institute, Brisbane, QLD, Australia.,Institute for Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.,School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia.,Translational Research Institute, School of Medicine, The University of Queensland Diamantina Institute, Brisbane, QLD, Australia
| | - Luke R Johnson
- Translational Research Institute, Brisbane, QLD, Australia.,Institute for Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.,School of Psychology and Counseling, Queensland University of Technology, Brisbane, QLD, Australia.,Department of Psychiatry and Center for the Study of Traumatic Stress, Uniformed Services University School of Medicine, Bethesda, MD, United States
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8
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Bergstrom HC. The neurocircuitry of remote cued fear memory. Neurosci Biobehav Rev 2016; 71:409-417. [PMID: 27693699 DOI: 10.1016/j.neubiorev.2016.09.028] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 09/25/2016] [Accepted: 09/27/2016] [Indexed: 11/16/2022]
Abstract
Memories of threatening, fear-evoking events can persist even over a lifetime. While fear memory is widely considered to be a highly persistent and durable form of memory, its circuits are not. This article reviews the dynamic temporal representation of remote fear memory in the brain, at the level of local circuits and distributed networks. Data from the study of Pavlovian cued fear conditioning suggests memory retrieval remains amygdala-dependent, even over protracted time scales, all the while interconnected cortical and subcortical circuits are newly recruited and progressively reorganized. A deeper understanding into how the neurocircuitry of cued fear memory reorganizes with the passage of time will advance our ongoing search for the elusive physical changes representing fear memories in the brain. Considering that persistent, pathological fear memories are a hallmark feature of post-traumatic stress disorder (PTSD), the behavioral and circuit-level study of remote cued fear memory retrieval adds a key element towards a systems understanding of PTSD.
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Affiliation(s)
- Hadley C Bergstrom
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, NY 12604, United States.
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9
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Bergstrom HC, Johnson LR. An organization of visual and auditory fear conditioning in the lateral amygdala. Neurobiol Learn Mem 2014; 116:1-13. [DOI: 10.1016/j.nlm.2014.07.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Revised: 07/14/2014] [Accepted: 07/15/2014] [Indexed: 10/25/2022]
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10
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Haws ME, Jaramillo TC, Espinosa F, Widman AJ, Stuber GD, Sparta DR, Tye KM, Russo SJ, Parada LF, Stavarache M, Kaplitt M, Bonci A, Powell CM. PTEN knockdown alters dendritic spine/protrusion morphology, not density. J Comp Neurol 2014; 522:1171-90. [PMID: 24264880 DOI: 10.1002/cne.23488] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 10/02/2013] [Accepted: 10/03/2013] [Indexed: 12/12/2022]
Abstract
Mutations in phosphatase and tensin homolog deleted on chromosome 10 (PTEN) are implicated in neuropsychiatric disorders including autism. Previous studies report that PTEN knockdown in neurons in vivo leads to increased spine density and synaptic activity. To better characterize synaptic changes in neurons lacking PTEN, we examined the effects of shRNA knockdown of PTEN in basolateral amygdala neurons on synaptic spine density and morphology by using fluorescent dye confocal imaging. Contrary to previous studies in the dentate gyrus, we find that knockdown of PTEN in basolateral amygdala leads to a significant decrease in total spine density in distal dendrites. Curiously, this decreased spine density is associated with increased miniature excitatory postsynaptic current frequency and amplitude, suggesting an increase in number and function of mature spines. These seemingly contradictory findings were reconciled by spine morphology analysis demonstrating increased mushroom spine density and size with correspondingly decreased thin protrusion density at more distal segments. The same analysis of PTEN conditional deletion in the dentate gyrus demonstrated that loss of PTEN does not significantly alter total density of dendritic protrusions in the dentate gyrus, but does decrease thin protrusion density and increases density of more mature mushroom spines. These findings suggest that, contrary to previous reports, PTEN knockdown may not induce de novo spinogenesis, but instead may increase synaptic activity by inducing morphological and functional maturation of spines. Furthermore, behavioral analysis of basolateral amygdala PTEN knockdown suggests that these changes limited only to the basolateral amygdala complex may not be sufficient to induce increased anxiety-related behaviors.
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Affiliation(s)
- Michael E Haws
- Department of Neurology & Neurotherapeutics, The University of Texas Southwestern Medical Center, Dallas, Texas, 75390-8813; Neuroscience Graduate Program, The University of Texas Southwestern Medical Center, Dallas, Texas, 75390-8813
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11
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Díaz-Mataix L, Tallot L, Doyère V. The amygdala: A potential player in timing CS–US intervals. Behav Processes 2014; 101:112-22. [DOI: 10.1016/j.beproc.2013.08.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 07/15/2013] [Accepted: 08/06/2013] [Indexed: 01/29/2023]
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12
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Bergstrom HC, McDonald CG, Dey S, Tang H, Selwyn RG, Johnson LR. The structure of Pavlovian fear conditioning in the amygdala. Brain Struct Funct 2012. [DOI: 10.1007/s00429-012-0478-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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13
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Coactivation of thalamic and cortical pathways induces input timing-dependent plasticity in amygdala. Nat Neurosci 2011; 15:113-22. [PMID: 22158512 PMCID: PMC3245819 DOI: 10.1038/nn.2993] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 10/19/2011] [Indexed: 02/06/2023]
Abstract
Long-term synaptic enhancements in cortical and thalamic auditory inputs to the lateral nucleus of the amygdala (LAn) mediate encoding of conditioned fear memory. It remained unknown, however, whether the convergent auditory conditioned stimulus (CSa) pathways may interact with each other producing changes in their synaptic function. Here we show that continuous paired stimulation of thalamic and cortical auditory inputs to the LAn with the interstimulus delay approximately mimicking a temporal pattern of their activation in behaving animals during auditory fear conditioning results in persistent potentiation of synaptic transmission in cortico-amygdala pathway in rat brain slices. This novel form of input timing-dependent plasticity (ITDP) in cortical input depends on InsP3-sensitive Ca2+ release from the internal stores and postsynaptic Ca2+ influx through calcium-permeable kainate receptors during its induction. ITDP in the auditory projections to the LAn, determined by characteristics of presynaptic activity patterns, may contribute to the encoding of the complex CSa.
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14
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Osan R, Tort ABL, Amaral OB. A mismatch-based model for memory reconsolidation and extinction in attractor networks. PLoS One 2011; 6:e23113. [PMID: 21826231 PMCID: PMC3149635 DOI: 10.1371/journal.pone.0023113] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 07/06/2011] [Indexed: 11/23/2022] Open
Abstract
The processes of memory reconsolidation and extinction have received increasing attention in recent experimental research, as their potential clinical applications begin to be uncovered. A number of studies suggest that amnestic drugs injected after reexposure to a learning context can disrupt either of the two processes, depending on the behavioral protocol employed. Hypothesizing that reconsolidation represents updating of a memory trace in the hippocampus, while extinction represents formation of a new trace, we have built a neural network model in which either simple retrieval, reconsolidation or extinction of a stored attractor can occur upon contextual reexposure, depending on the similarity between the representations of the original learning and reexposure sessions. This is achieved by assuming that independent mechanisms mediate Hebbian-like synaptic strengthening and mismatch-driven labilization of synaptic changes, with protein synthesis inhibition preferentially affecting the former. Our framework provides a unified mechanistic explanation for experimental data showing (a) the effect of reexposure duration on the occurrence of reconsolidation or extinction and (b) the requirement of memory updating during reexposure to drive reconsolidation.
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Affiliation(s)
- Remus Osan
- Center for Neuroscience, Boston University, Boston, Massachusetts, United States of America
- Center for Biodynamics, Boston University, Boston, Massachusetts, United States of America
- Department of Mathematics and Statistics, Boston University, Boston, Massachusetts, United States of America
| | - Adriano B. L. Tort
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
- Edmond and Lily Safra International Institute of Neuroscience of Natal, Natal, Rio Grande do Norte, Brazil
| | - Olavo B. Amaral
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- * E-mail:
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15
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Johnson LR, McGuire J, Lazarus R, Palmer AA. Pavlovian fear memory circuits and phenotype models of PTSD. Neuropharmacology 2011; 62:638-46. [PMID: 21782833 DOI: 10.1016/j.neuropharm.2011.07.004] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 06/07/2011] [Accepted: 07/06/2011] [Indexed: 11/26/2022]
Abstract
Pavlovian fear conditioning, also known as classical fear conditioning is an important model in the study of the neurobiology of normal and pathological fear. Progress in the neurobiology of Pavlovian fear also enhances our understanding of disorders such as posttraumatic stress disorder (PTSD) and with developing effective treatment strategies. Here we describe how Pavlovian fear conditioning is a key tool for understanding both the neurobiology of fear and the mechanisms underlying variations in fear memory strength observed across different phenotypes. First we discuss how Pavlovian fear models aspects of PTSD. Second, we describe the neural circuits of Pavlovian fear and the molecular mechanisms within these circuits that regulate fear memory. Finally, we show how fear memory strength is heritable; and describe genes which are specifically linked to both changes in Pavlovian fear behavior and to its underlying neural circuitry. These emerging data begin to define the essential genes, cells and circuits that contribute to normal and pathological fear. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.
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Affiliation(s)
- Luke R Johnson
- Psychiatry and Neuroscience, School of Medicine, Uniformed Services University (USU), Bethesda, MD 20814, USA.
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16
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Johnson LR, Hou M, Prager EM, Ledoux JE. Regulation of the Fear Network by Mediators of Stress: Norepinephrine Alters the Balance between Cortical and Subcortical Afferent Excitation of the Lateral Amygdala. Front Behav Neurosci 2011; 5:23. [PMID: 21647395 PMCID: PMC3102213 DOI: 10.3389/fnbeh.2011.00023] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Accepted: 04/18/2011] [Indexed: 12/01/2022] Open
Abstract
Pavlovian auditory fear conditioning involves the integration of information about an acoustic conditioned stimulus (CS) and an aversive unconditioned stimulus in the lateral nucleus of the amygdala (LA). The auditory CS reaches the LA subcortically via a direct connection from the auditory thalamus and also from the auditory association cortex itself. How neural modulators, especially those activated during stress, such as norepinephrine (NE), regulate synaptic transmission and plasticity in this network is poorly understood. Here we show that NE inhibits synaptic transmission in both the subcortical and cortical input pathway but that sensory processing is biased toward the subcortical pathway. In addition binding of NE to β-adrenergic receptors further dissociates sensory processing in the LA. These findings suggest a network mechanism that shifts sensory balance toward the faster but more primitive subcortical input.
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Affiliation(s)
- Luke R Johnson
- Department of Psychiatry and Program in Neuroscience, Uniformed Services University Bethesda, MD, USA
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Meis S, Stork O, Munsch T. Neuropeptide S-mediated facilitation of synaptic transmission enforces subthreshold theta oscillations within the lateral amygdala. PLoS One 2011; 6:e18020. [PMID: 21437203 PMCID: PMC3060922 DOI: 10.1371/journal.pone.0018020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 02/21/2011] [Indexed: 12/03/2022] Open
Abstract
The neuropeptide S (NPS) receptor system modulates neuronal circuit activity in the amygdala in conjunction with fear, anxiety and the expression and extinction of previously acquired fear memories. Using in vitro brain slice preparations of transgenic GAD67-GFP (Δneo) mice, we investigated the effects of NPS on neural activity in the lateral amygdala as a key region for the formation and extinction of fear memories. We are able to demonstrate that NPS augments excitatory glutamatergic synaptic input onto both projection neurons and interneurons of the lateral amygdala, resulting in enhanced spike activity of both types of cells. These effects were at least in part mediated by presynaptic mechanisms. In turn, inhibition of projection neurons by local interneurons was augmented by NPS, and subthreshold oscillations were strengthened, leading to their shift into the theta frequency range. These data suggest that the multifaceted effects of NPS on amygdaloid circuitry may shape behavior-related network activity patterns in the amygdala and reflect the peptide's potent activity in various forms of affective behavior and emotional memory.
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Affiliation(s)
- Susanne Meis
- Institut für Physiologie,
Otto-von-Guericke-Universität, Magdeburg, Germany
- Center for Behavioral Brain Sciences,
Magdeburg, Germany
| | - Oliver Stork
- Center for Behavioral Brain Sciences,
Magdeburg, Germany
- Abteilung für Genetik & Molekulare
Neurobiologie, Institut für Biologie, Otto-von-Guericke-Universität,
Magdeburg, Germany
| | - Thomas Munsch
- Institut für Physiologie,
Otto-von-Guericke-Universität, Magdeburg, Germany
- Center for Behavioral Brain Sciences,
Magdeburg, Germany
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18
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Zschenderlein C, Gebhardt C, von Bohlen und Halbach O, Kulisch C, Albrecht D. Capsaicin-induced changes in LTP in the lateral amygdala are mediated by TRPV1. PLoS One 2011; 6:e16116. [PMID: 21249195 PMCID: PMC3020947 DOI: 10.1371/journal.pone.0016116] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Accepted: 12/14/2010] [Indexed: 01/15/2023] Open
Abstract
The transient receptor potential vanilloid type 1 (TRPV1) channel is a well recognized polymodal signal detector that is activated by painful stimuli such as capsaicin. Here, we show that TRPV1 is expressed in the lateral nucleus of the amygdala (LA). Despite the fact that the central amygdala displays the highest neuronal density, the highest density of TRPV1 labeled neurons was found within the nuclei of the basolateral complex of the amygdala. Capsaicin specifically changed the magnitude of long-term potentiation (LTP) in the LA in brain slices of mice depending on the anesthetic (ether, isoflurane) used before euthanasia. After ether anesthesia, capsaicin had a suppressive effect on LA-LTP both in patch clamp and in extracellular recordings. The capsaicin-induced reduction of LTP was completely blocked by the nitric oxide synthase (NOS) inhibitor L-NAME and was absent in neuronal NOS as well as in TRPV1 deficient mice. The specific antagonist of cannabinoid receptor type 1 (CB1), AM 251, was also able to reduce the inhibitory effect of capsaicin on LA-LTP, suggesting that stimulation of TRPV1 provokes the generation of anandamide in the brain which seems to inhibit NO synthesis. After isoflurane anesthesia before euthanasia capsaicin caused a TRPV1-mediated increase in the magnitude of LA-LTP. Therefore, our results also indicate that the appropriate choice of the anesthetics used is an important consideration when brain plasticity and the action of endovanilloids will be evaluated. In summary, our results demonstrate that TRPV1 may be involved in the amygdala control of learning mechanisms.
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Affiliation(s)
- Carsten Zschenderlein
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin, CVK, Berlin, Germany
| | - Christine Gebhardt
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin, CVK, Berlin, Germany
| | | | - Christoph Kulisch
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin, CVK, Berlin, Germany
| | - Doris Albrecht
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin, CVK, Berlin, Germany
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Gos T, Krell D, Bielau H, Steiner J, Mawrin C, Trübner K, Brisch R, Bernstein HG, Jankowski Z, Bogerts B. Demonstration of disturbed activity of the lateral amygdaloid nucleus projection neurons in depressed patients by the AgNOR staining method. J Affect Disord 2010; 126:402-10. [PMID: 20444504 DOI: 10.1016/j.jad.2010.04.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Revised: 04/08/2010] [Accepted: 04/08/2010] [Indexed: 10/19/2022]
Abstract
BACKGROUND The aim to find a morphological biomarker of disturbed activity of the lateral amygdaloid nucleus in depression was approached by a karyometric analysis of projection neurons. METHODS The study was performed on paraffin-embedded brains from 19 depressed patients from both the major depressive disorder (MDD) and the bipolar disorder (BD) diagnostic groups, including 10 suicides, and 24 matched controls. The karyometric parameters of the lateral amygdaloid nucleus (La) projection neurons bilaterally were evaluated by the argyrophilic nucleolar organiser region (AgNOR) silver staining method. RESULTS An increased AgNOR number was found in the right La in suicides compared to controls. The intra-group comparisons between the hemispheres suggest a disturbed amygdaloid lateralisation in depressed patients. The effects were independent from psychotropic medication. There was a strong positive correlation between the nuclear area in La projection neurons and prefrontal limbic areas pyramidal neurons in the right hemisphere specific for suicide and MDD. LIMITATIONS A major limitation of this study is the relatively small number of cases. A further limitation is given by the lack of data on drug exposure across the entire lifespan. CONCLUSION The results suggest that depressed patients from both the MDD and BD diagnostic groups exhibit an increased activity of the La output neurons specific for suicidal patients. The distinctness of the diagnostic groups of mood disorders was accentuated in the correlation analysis. This putative hyperactivity was specific for the right hemisphere and psychotropic medication most likely did not counteract it.
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Affiliation(s)
- Tomasz Gos
- Institute of Forensic Medicine, Medical University of Gdańsk, Poland.
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Lazzaro SC, Hou M, Cunha C, LeDoux JE, Cain CK. Antagonism of lateral amygdala alpha1-adrenergic receptors facilitates fear conditioning and long-term potentiation. Learn Mem 2010; 17:489-93. [PMID: 20870745 DOI: 10.1101/lm.1918210] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Norepinephrine receptors have been studied in emotion, memory, and attention. However, the role of alpha1-adrenergic receptors in fear conditioning, a major model of emotional learning, is poorly understood. We examined the effect of terazosin, an alpha1-adrenergic receptor antagonist, on cued fear conditioning. Systemic or intra-lateral amygdala terazosin delivered before conditioning enhanced short- and long-term memory. Terazosin delivered after conditioning did not affect consolidation. In vitro, terazosin impaired lateral amygdala inhibitory postsynaptic currents leading to facilitation of excitatory postsynaptic currents and long-term potentiation. Since alpha1 blockers are prescribed for hypertension and post-traumatic stress disorder, these results may have important clinical implications.
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Affiliation(s)
- Stephanie C Lazzaro
- Center for Neural Science, New York University, New York, New York 10003, USA.
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Johnson LR, Ledoux JE, Doyère V. Hebbian reverberations in emotional memory micro circuits. Front Neurosci 2009; 3:198-205. [PMID: 20011142 PMCID: PMC2751649 DOI: 10.3389/neuro.01.027.2009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2009] [Accepted: 07/09/2009] [Indexed: 11/13/2022] Open
Abstract
The study of memory in most behavioral paradigms, including emotional memory paradigms, has focused on the feed forward components that underlie Hebb's first postulate, associative synaptic plasticity. Hebb's second postulate argues that activated ensembles of neurons reverberate in order to provide temporal coordination of different neural signals, and thereby facilitate coincidence detection. Recent evidence from our groups has suggested that the lateral amygdala (LA) contains recurrent microcircuits and that these may reverberate. Additionally this reverberant activity is precisely timed with latencies that would facilitate coincidence detection between cortical and sub cortical afferents to the LA. Thus, recent data at the microcircuit level in the amygdala provide some physiological evidence in support of the second Hebbian postulate.
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Affiliation(s)
- Luke R Johnson
- Department of Psychiatry and Program in Neuroscience, USU Bethesda, MD, USA
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Muller T, Albrecht D, Gebhardt C. Both NR2A and NR2B subunits of the NMDA receptor are critical for long-term potentiation and long-term depression in the lateral amygdala of horizontal slices of adult mice. Learn Mem 2009; 16:395-405. [DOI: 10.1101/lm.1398709] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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