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Centofante E, Fralleoni L, Lupascu CA, Migliore M, Rinaldi A, Mele A. Specific patterns of neural activity in the hippocampus after massed or distributed spatial training. Sci Rep 2023; 13:13357. [PMID: 37587232 PMCID: PMC10432541 DOI: 10.1038/s41598-023-39882-0] [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: 03/01/2023] [Accepted: 08/01/2023] [Indexed: 08/18/2023] Open
Abstract
Training with long inter-session intervals, termed distributed training, has long been known to be superior to training with short intervals, termed massed training. In the present study we compared c-Fos expression after massed and distributed training protocols in the Morris water maze to outline possible differences in the learning-induced pattern of neural activation in the dorsal CA1 in the two training conditions. The results demonstrate that training and time lags between learning opportunities had an impact on the pattern of neuronal activity in the dorsal CA1. Mice trained with the distributed protocol showed sustained neuronal activity in the postero-distal component of the dorsal CA1. In parallel, in trained mice we found more active cells that tended to constitute spatially restricted clusters, whose degree increased with the increase in the time lags between learning trials. Moreover, activated cell assemblies demonstrated increased stability in their spatial organization after distributed as compared to massed training or control condition. Finally, using a machine learning algorithm we found that differences in the number of c-Fos positive cells and their location in the dorsal CA1 could be predictive of the training protocol used. These results suggest that the topographic organization and the spatial location of learning activated cell assemblies might be critical to promote the increased stability of the memory trace induced by distributed training.
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Affiliation(s)
- Eleonora Centofante
- Department of Biology and Biotechnology 'C. Darwin' - Centre for Research in Neurobiology 'D.Bovet', Sapienza University of Rome, P.Le A. Moro, 5, 00185, Rome, Italy
- Institute of Biophysics, National Research Council, Palermo, Italy
| | - Luca Fralleoni
- Department of Biology and Biotechnology 'C. Darwin' - Centre for Research in Neurobiology 'D.Bovet', Sapienza University of Rome, P.Le A. Moro, 5, 00185, Rome, Italy
| | - Carmen A Lupascu
- Institute of Biophysics, National Research Council, Palermo, Italy
| | - Michele Migliore
- Institute of Biophysics, National Research Council, Palermo, Italy
| | - Arianna Rinaldi
- Department of Biology and Biotechnology 'C. Darwin' - Centre for Research in Neurobiology 'D.Bovet', Sapienza University of Rome, P.Le A. Moro, 5, 00185, Rome, Italy
| | - Andrea Mele
- Department of Biology and Biotechnology 'C. Darwin' - Centre for Research in Neurobiology 'D.Bovet', Sapienza University of Rome, P.Le A. Moro, 5, 00185, Rome, Italy.
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2
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Hakim M, Beecher K, Jacques A, Chaaya N, Belmer A, Battle AR, Johnson LR, Bartlett SE, Chehrehasa F. Retrieval of olfactory fear memory alters cell proliferation and expression of pCREB and pMAPK in the corticomedial amygdala and piriform cortex. Chem Senses 2022; 47:6673813. [PMID: 35997758 PMCID: PMC9397123 DOI: 10.1093/chemse/bjac021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The brain forms robust associations between odors and emotionally salient memories, making odors especially effective at triggering fearful or traumatic memories. Using Pavlovian olfactory fear conditioning (OFC), a variant of the traditional tone-shock paradigm, this study explored the changes involved in its processing. We assessed the expression of neuronal plasticity markers phosphorylated cyclic adenosine monophosphate response element binding protein (pCREB) and phosphorylated mitogen-activated protein kinase (pMAPK) 24 h and 14 days following OFC, in newborn neurons (EdU+) and in brain regions associated with olfactory memory processing; the olfactory bulb, piriform cortex, amygdale, and hippocampus. Here, we show that all proliferating neurons in the dentate gyrus of the hippocampus and glomerular layer of the olfactory bulb were colocalized with pCREB at 24 h and 14 days post-conditioning, and the number of proliferating neurons at both time points were statistically similar. This suggests the occurrence of long-term potentiation within the neurons of this pathway. Finally, OFC significantly increased the density of pCREB- and pMAPK-positive immunoreactive neurons in the medial and cortical subnuclei of the amygdala and the posterior piriform cortex, suggesting their key involvement in its processing. Together, our investigation identifies changes in neuroplasticity within critical neural circuits responsible for olfactory fear memory.
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Affiliation(s)
- Marziah Hakim
- Addiction Neuroscience and Obesity Laboratory, School of Biomedical Sciences, Faculty of Health, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Kate Beecher
- Addiction Neuroscience and Obesity Laboratory, School of Clinical Sciences, Faculty of Health, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Angela Jacques
- Addiction Neuroscience and Obesity Laboratory, School of Clinical Sciences, Faculty of Health, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Nicholas Chaaya
- Addiction Neuroscience and Obesity Laboratory, School of Clinical Sciences, Faculty of Health, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Arnauld Belmer
- Addiction Neuroscience and Obesity Laboratory, School of Clinical Sciences, Faculty of Health, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Andrew R Battle
- Addiction Neuroscience and Obesity Laboratory, School of Biomedical Sciences, Faculty of Health, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Luke R Johnson
- Addiction Neuroscience and Obesity Laboratory, School of Clinical Sciences, Faculty of Health, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia.,School of Medicine. Division of Psychology, University of Tasmania, Launceston, TAS, Australia
| | - Selena E Bartlett
- Addiction Neuroscience and Obesity Laboratory, School of Clinical Sciences, Faculty of Health, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Fatemeh Chehrehasa
- Addiction Neuroscience and Obesity Laboratory, School of Biomedical Sciences, Faculty of Health, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
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3
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Chaaya N, Wang J, Jacques A, Beecher K, Chaaya M, Battle AR, Johnson LR, Chehrehasa F, Belmer A, Bartlett SE. Contextual Fear Memory Maintenance Changes Expression of pMAPK, BDNF and IBA-1 in the Pre-limbic Cortex in a Layer-Specific Manner. Front Neural Circuits 2021; 15:660199. [PMID: 34295224 PMCID: PMC8291085 DOI: 10.3389/fncir.2021.660199] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 06/07/2021] [Indexed: 12/30/2022] Open
Abstract
Post-traumatic stress disorder (PTSD) is a debilitating and chronic fear-based disorder. Pavlovian fear conditioning protocols have long been utilised to manipulate and study these fear-based disorders. Contextual fear conditioning (CFC) is a particular Pavlovian conditioning procedure that pairs fear with a particular context. Studies on the neural mechanisms underlying the development of contextual fear memories have identified the medial prefrontal cortex (mPFC), or more specifically, the pre-limbic cortex (PL) of the mPFC as essential for the expression of contextual fear. Despite this, little research has explored the role of the PL in contextual fear memory maintenance or examined the role of neuronal mitogen-activated protein kinase (pMAPK; ERK 1/2), brain-derived neurotrophic factor (BDNF), and IBA-1 in microglia in the PL as a function of Pavlovian fear conditioning. The current study was designed to evaluate how the maintenance of two different long-term contextual fear memories leads to changes in the number of immune-positive cells for two well-known markers of neural activity (phosphorylation of MAPK and BDNF) and microglia (IBA-1). Therefore, the current experiment is designed to assess the number of immune-positive pMAPK and BDNF cells, microglial number, and morphology in the PL following CFC. Specifically, 2 weeks following conditioning, pMAPK, BDNF, and microglia number and morphology were evaluated using well-validated antibodies and immunohistochemistry (n = 12 rats per group). A standard CFC protocol applied to rats led to increases in pMAPK, BDNF expression and microglia number as compared to control conditions. Rats in the unpaired fear conditioning (UFC) procedure, despite having equivalent levels of fear to context, did not have any change in pMAPK, BDNF expression and microglia number in the PL compared to the control conditions. These data suggest that alterations in the expression of pMAPK, BDNF, and microglia in the PL can occur for up to 2 weeks following CFC. Together the data suggest that MAPK, BDNF, and microglia within the PL of the mPFC may play a role in contextual fear memory maintenance.
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Affiliation(s)
- Nicholas Chaaya
- School of Clinical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia.,Translational Research Institute, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
| | - Joshua Wang
- School of Clinical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia.,Translational Research Institute, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
| | - Angela Jacques
- School of Clinical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia.,Translational Research Institute, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
| | - Kate Beecher
- School of Clinical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia.,Translational Research Institute, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
| | - Michael Chaaya
- School of Clinical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia.,Translational Research Institute, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
| | - Andrew Raymond Battle
- Translational Research Institute, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia.,School of Biomedical Science, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia.,University of Queensland Diamantina Institute, Translational Research Institute, Brisbane, QLD, Australia
| | - Luke R Johnson
- Translational Research Institute, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia.,School of Psychology and Counselling, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia.,Center for the Study of Traumatic Stress, Department of Psychiatry, USU School of Medicine, Bethesda, MD, United States
| | - Fatemeh Chehrehasa
- Translational Research Institute, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia.,School of Biomedical Science, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
| | - Arnauld Belmer
- School of Clinical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia.,Translational Research Institute, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
| | - Selena E Bartlett
- School of Clinical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia.,Translational Research Institute, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
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4
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O'Leary TP, Sullivan KE, Wang L, Clements J, Lemire AL, Cembrowski MS. Extensive and spatially variable within-cell-type heterogeneity across the basolateral amygdala. eLife 2020; 9:59003. [PMID: 32869744 PMCID: PMC7486123 DOI: 10.7554/elife.59003] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 08/26/2020] [Indexed: 01/04/2023] Open
Abstract
The basolateral amygdala complex (BLA), extensively connected with both local amygdalar nuclei as well as long-range circuits, is involved in a diverse array of functional roles. Understanding the mechanisms of such functional diversity will be greatly informed by understanding the cell-type-specific landscape of the BLA. Here, beginning with single-cell RNA sequencing, we identified both discrete and graded continuous gene-expression differences within the mouse BLA. Via in situ hybridization, we next mapped this discrete transcriptomic heterogeneity onto a sharp spatial border between the basal and lateral amygdala nuclei, and identified continuous spatial gene-expression gradients within each of these regions. These discrete and continuous spatial transformations of transcriptomic cell-type identity were recapitulated by local morphology as well as long-range connectivity. Thus, BLA excitatory neurons are a highly heterogenous collection of neurons that spatially covary in molecular, cellular, and circuit properties. This heterogeneity likely drives pronounced spatial variation in BLA computation and function.
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Affiliation(s)
- Timothy P O'Leary
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, Canada
| | - Kaitlin E Sullivan
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, Canada
| | - Lihua Wang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Jody Clements
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Andrew L Lemire
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Mark S Cembrowski
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, Canada.,Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada.,School of Biomedical Engineering, University of British Columbia, Vancouver, Canada
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5
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Bergstrom HC. Assaying Fear Memory Discrimination and Generalization: Methods and Concepts. CURRENT PROTOCOLS IN NEUROSCIENCE 2020; 91:e89. [PMID: 31995285 PMCID: PMC7000165 DOI: 10.1002/cpns.89] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Generalization describes the transfer of conditioned responding to stimuli that perceptually differ from the original conditioned stimulus. One arena in which discriminant and generalized responding is of particular relevance is when stimuli signal the potential for harm. Aversive (fear) conditioning is a leading behavioral model for studying associative learning and memory processes related to threatening stimuli. This article describes a step-by-step protocol for studying discrimination and generalization using cued fear conditioning in rodents. Alternate conditioning paradigms, including context generalization, differential generalization, discrimination training, and safety learning, are also described. The protocol contains instructions for constructing a cued fear memory generalization gradient and methods for isolating discrete cued-from-context cued conditioned responses (i.e., "the baseline issue"). The preclinical study of generalization is highly pertinent in the context of fear learning and memory because a lack of fear discrimination (overgeneralization) likely contributes to the etiology of anxiety-related disorders and post-traumatic stress disorder. © 2020 by John Wiley & Sons, Inc. Basic Protocol 1: Tone cued fear generalization gradient Basic Protocol 2: Quantification of freezing Support Protocol: Alternate conditioning paradigms.
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Affiliation(s)
- Hadley C Bergstrom
- Vassar College, Department of Psychological Science, Program in Neuroscience and Behavior, Poughkeepsie, New York
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6
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Chaaya N, Jacques A, Belmer A, Beecher K, Ali SA, Chehrehasa F, Battle AR, Johnson LR, Bartlett SE. Contextual Fear Conditioning Alter Microglia Number and Morphology in the Rat Dorsal Hippocampus. Front Cell Neurosci 2019; 13:214. [PMID: 31139053 PMCID: PMC6527886 DOI: 10.3389/fncel.2019.00214] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Accepted: 04/29/2019] [Indexed: 12/11/2022] Open
Abstract
Contextual fear conditioning is a Pavlovian conditioning paradigm capable of rapidly creating fear memories to contexts, such as rooms or chambers. Contextual fear conditioning protocols have long been utilized to evaluate how fear memories are consolidated, maintained, expressed, recalled, and extinguished within the brain. These studies have identified the lateral portion of the amygdala and the dorsal portion of the hippocampus as essential for contextual fear memory consolidation. The current study was designed to evaluate how two different contextual fear memories alter amygdala and hippocampus microglia, brain derived neurotrophic factor (BDNF), and phosphorylated cyclic-AMP response element binding (pCREB). We find rats provided with standard contextual fear conditioning to have more microglia and more cells expressing BDNF in the dentate gyrus as compared to a context only control group. Additionally, standard contextual fear conditioning altered microglia morphology to become amoeboid in shape – a common response to central nervous system insult, such as traumatic brain injury, infection, ischemia, and more. The unpaired fear conditioning procedure (whereby non-reinforced and non-overlapping auditory tones were provided at random intervals during conditioning), despite producing equivalent levels of fear as the standard procedure, did not alter microglia, BDNF or pCREB number in any dorsal hippocampus or lateral amygdala brain regions. Despite this, the unpaired fear conditioning protocol produced some alterations in microglia morphology, but less compared to rats provided with standard contextual fear conditioning. Results from this study demonstrate that contextual fear conditioning is capable of producing large alterations to dentate gyrus plasticity and microglia, whereas unpaired fear conditioning only produces minor changes to microglia morphology. These data show, for the first time, that Pavlovian fear conditioning protocols can induce similar responses as trauma, infection or other insults within the central nervous system.
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Affiliation(s)
- Nicholas Chaaya
- School of Clinical Sciences, Queensland University of Technology, Brisbane, QLD, Australia.,Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Angela Jacques
- School of Clinical Sciences, Queensland University of Technology, Brisbane, QLD, Australia.,Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Arnauld Belmer
- School of Clinical Sciences, Queensland University of Technology, Brisbane, QLD, Australia.,Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Kate Beecher
- School of Clinical Sciences, Queensland University of Technology, Brisbane, QLD, Australia.,Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Syed A Ali
- School of Clinical Sciences, Queensland University of Technology, Brisbane, QLD, Australia.,Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Fatemeh Chehrehasa
- Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia.,School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Andrew R Battle
- Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia.,School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia.,Diamantina Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Luke R Johnson
- Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia.,School of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia.,Center for the Study of Traumatic Stress, Department of Psychiatry, Uniformed Services University School of Medicine, Bethesda, MD, United States
| | - Selena E Bartlett
- School of Clinical Sciences, Queensland University of Technology, Brisbane, QLD, Australia.,Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
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7
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Jacques A, Chaaya N, Hettiarachchi C, Carmody ML, Beecher K, Belmer A, Chehrehasa F, Bartlett S, Battle AR, Johnson LR. Microtopography of fear memory consolidation and extinction retrieval within prefrontal cortex and amygdala. Psychopharmacology (Berl) 2019; 236:383-397. [PMID: 30610350 DOI: 10.1007/s00213-018-5068-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 10/04/2018] [Indexed: 10/27/2022]
Abstract
RATIONALE The precise neural circuitry that encodes fear memory and its extinction within the brain are not yet fully understood. Fearful memories can be persistent, resistant to extinction, and associated with psychiatric disorders, especially post-traumatic stress disorder (PTSD). Here, we investigated the microtopography of neurons activated during the recall of an extinguished fear memory, as well as the influence of time on this microtopography. METHODS We used the plasticity-related phosphorylated mitogen-activated protein kinase (pMAPK) to identify neurons activated in the recall of consolidated and extinguished auditory Pavlovian fear memories in rats. Quantitatively matched brain regions were used to investigate activity in the amygdala and prefrontal cortex. RESULTS Recall of a consolidated, nonextinguished auditory fear memory resulted in a significantly greater number of activated neurons located in the dorsolateral subdivision of the lateral amygdala (LADL) when recalled 24 h after consolidation but not when recalled 7 days later. We found that the recall of an extinction memory was associated with pMAPK activation in the ventrolateral subdivision of the lateral amygdala (LAVL). Next, we showed that the pattern of pMAPK expression in the prelimbic cortex differed spatially following temporal variation in the recall of that memory. The deep and superficial layers of the pre-limbic cortex were engaged in recent recall of a fear memory, but only the superficial layers were recruited if the recall occurred 7 days later. CONCLUSIONS Collectively, our findings demonstrate a functional microtopography of auditory fear memory during consolidation and extinction at the microanatomical level within the lateral amygdala and medial prefrontal cortex.
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Affiliation(s)
- Angela Jacques
- School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia.,Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia
| | - Nicholas Chaaya
- School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia.,Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia
| | - Chiemi Hettiarachchi
- Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia
| | - Marie-Louise Carmody
- School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia.,Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia
| | - Kate Beecher
- Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia.,School of Clinical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Arnauld Belmer
- Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia.,School of Clinical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Fatemeh Chehrehasa
- Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia.,School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Selena Bartlett
- Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia.,School of Clinical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Andrew R Battle
- Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia.,School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia.,The University of Queensland Diamantina Institute, Brisbane, Australia
| | - Luke R Johnson
- School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia. .,Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia. .,Center for the Study of Traumatic Stress, Department of Psychiatry, USU School of Medicine, Bethesda, MD, USA.
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8
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Chaaya N, Jacques A, Belmer A, Richard DJ, Bartlett SE, Battle AR, Johnson LR. Localization of Contextual and Context Removed Auditory Fear Memory within the Basolateral Amygdala Complex. Neuroscience 2018; 398:231-251. [PMID: 30552931 DOI: 10.1016/j.neuroscience.2018.12.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 11/30/2018] [Accepted: 12/03/2018] [Indexed: 01/20/2023]
Abstract
Debilitating and persistent fear memories can rapidly form in humans following exposure to traumatic events. Fear memories can also be generated and studied in animals via Pavlovian fear conditioning. The current study was designed to evaluate basolateral amygdala complex (BLC) involvement following the formation of different fear memories (two contextual fear memories and one adjusted auditory fear memory). Fear memories were created in the same context with five 1.0 mA (0.50 s) foot-shocks and, where necessary, five auditory tones (5 kHz, 75 dB, 20 s). The adjusted auditory fear conditioning protocol was employed to remove background contextual fear and produce isolated auditory fear memories. Immunofluorescent labeling was utilized to identify neurons expressing immediate early genes (IEGs). We found the two contextual fear conditioning (CFC) procedures to produce similar levels of fear-related freezing to context. Contextual fear memories produced increases in BLC IEG expression with distinct and separate patterns of expression. These data suggest contextual fear memories created in slightly altered contexts, can produce unique patterns of amygdala activation. The adjusted auditory fear conditioning procedure produced memories to a tone, but not to a context. This group, where no contextual fear was present, had a significant reduction in BLC IEG expression. These data suggest background contextual fear memories, created in standard auditory fear conditioning protocols, contribute significantly to increases in amygdala activation.
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Affiliation(s)
- N Chaaya
- School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia; Institute of Health and Biomedical Innovation, Queensland University of Technology at Translational Research Institute, Brisbane, Australia
| | - A Jacques
- School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia; Institute of Health and Biomedical Innovation, Queensland University of Technology at Translational Research Institute, Brisbane, Australia
| | - A Belmer
- Institute of Health and Biomedical Innovation, Queensland University of Technology at Translational Research Institute, Brisbane, Australia; School of Clinical Sciences, Queensland University of Technology, Brisbane, Australia
| | - D J Richard
- Institute of Health and Biomedical Innovation, Queensland University of Technology at Translational Research Institute, Brisbane, Australia; School of Biomedical Science, Queensland University of Technology, Brisbane, Australia
| | - S E Bartlett
- Institute of Health and Biomedical Innovation, Queensland University of Technology at Translational Research Institute, Brisbane, Australia; School of Clinical Sciences, Queensland University of Technology, Brisbane, Australia
| | - A R Battle
- Institute of Health and Biomedical Innovation, Queensland University of Technology at Translational Research Institute, Brisbane, Australia; School of Biomedical Science, Queensland University of Technology, Brisbane, Australia; The University of Queensland Diamantina Institute, Brisbane, QLD 4102, Australia
| | - L R Johnson
- School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia; Institute of Health and Biomedical Innovation, Queensland University of Technology at Translational Research Institute, Brisbane, Australia; Center for the Study of Traumatic Stress, Department of Psychiatry, USU School of Medicine, Bethesda, MD, USA.
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9
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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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10
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Chaaya N, Battle AR, Johnson LR. An update on contextual fear memory mechanisms: Transition between Amygdala and Hippocampus. Neurosci Biobehav Rev 2018; 92:43-54. [DOI: 10.1016/j.neubiorev.2018.05.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 03/02/2018] [Accepted: 05/08/2018] [Indexed: 12/27/2022]
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11
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Neurons Specifically Activated by Fear Learning in Lateral Amygdala Display Increased Synaptic Strength. eNeuro 2018; 5:eN-NWR-0114-18. [PMID: 30027112 PMCID: PMC6051595 DOI: 10.1523/eneuro.0114-18.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 06/03/2018] [Accepted: 06/03/2018] [Indexed: 12/19/2022] Open
Abstract
The lateral amygdala (LA) plays a critical role in the formation of fear-conditioned associative memories. Previous studies have used c-fos regulated expression to identify a spatially restricted population of neurons within the LA that is specifically activated by fear learning. These neurons are likely to be a part of a memory engram, but, to date, functional evidence for this has been lacking. We show that neurons within a spatially restricted region of the LA had an increase in both the frequency and amplitude of spontaneous postsynaptic currents (sPSC) when compared to neurons recorded from home cage control mice. We then more specifically addressed if this increased synaptic activity was limited to learning-activated neurons. Using a fos-tau-LacZ (FTL) transgenic mouse line, we developed a fluorescence-based method of identifying and recording from neurons activated by fear learning (FTL+) in acute brain slices. An increase in frequency and amplitude of sPSCs was observed in FTL+ neurons when compared to nonactivated FTL− neurons in fear-conditioned mice. No learning-induced changes were observed in the action potential (AP) input-output relationships. These findings support the idea that a discrete LA neuron population forms part of a memory engram through changes in synaptic connectivity.
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12
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Pollack GA, Bezek JL, Lee SH, Scarlata MJ, Weingast LT, Bergstrom HC. Cued fear memory generalization increases over time. Learn Mem 2018; 25:298-308. [PMID: 29907637 PMCID: PMC6004064 DOI: 10.1101/lm.047555.118] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 04/13/2018] [Indexed: 01/04/2023]
Abstract
Fear memory is a highly stable and durable form of memory, even over vast (remote) time frames. Nevertheless, some elements of fear memory can be forgotten, resulting in generalization. The purpose of this study is to determine how cued fear memory generalizes over time and measure underlying patterns of cortico-amygdala synaptic plasticity. We established generalization gradients at recent (1-d) and remote (30-d) retention intervals following auditory cued fear conditioning in adult male C57BL/6 mice. Results revealed a flattening of the generalization gradient (increased generalization) that was dissociated from contextual fear generalization, indicating a specific influence of time on cued fear memory performance. This effect reversed after a brief exposure to the novel stimulus soon after learning. Measurements from cortico-amygdala imaging of the activity-regulated cytoskeletal Arc/arg 3.1 (Arc) protein using immunohistochemistry after cued fear memory retrieval revealed a stable pattern of Arc expression in the dorsolateral amygdala, but temporally dynamic expression in the cortex. Over time, increased fear memory generalization was associated with a reduction in Arc expression in the agranular insular and infralimbic cortices while discrimination learning was associated with increased Arc expression in the prelimbic cortex. These data identify the dorsolateral amygdala, medial prefrontal, and insular cortices as loci for synaptic plasticity underlying cued fear memory generalization over time.
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Affiliation(s)
- Gabrielle A Pollack
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, New York 12604 USA
| | - Jessica L Bezek
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, New York 12604 USA
| | - Serena H Lee
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, New York 12604 USA
| | - Miranda J Scarlata
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, New York 12604 USA
| | - Leah T Weingast
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, New York 12604 USA
| | - Hadley C Bergstrom
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, New York 12604 USA
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13
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Li W, Yu L, Yan X, Cai L, Wan L, Teng Q, Li Y, Wang Y, Xu H. Reduced Cyclic Adenosine Monophosphate Level in Hippocampal CA1 Participates in Propofol Induced Amnesia in Rats. Front Neurosci 2018; 12:337. [PMID: 29875624 PMCID: PMC5974205 DOI: 10.3389/fnins.2018.00337] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 04/30/2018] [Indexed: 11/20/2022] Open
Abstract
Propofol inhibits long-term potentiation (LTP) in the hippocampal CA1 region and impedes episodic memory formation. However, the molecular mechanisms involved in the effect of propofol are still poorly understood. It had been reported that propofol inhibited cAMP response element binding protein signaling, which was proposed to contribute to memory retention impairment in rats. Here, we first demonstrated that propofol perfusion could inhibit forskolin induced LTP in the rat hippocampal CA1 slices. Propofol also reduced the level of cAMP, which could be reversed by non-selective PDE inhibitor IBMX. We further discovered that propofol could increase both PDE4 activity and PDE4AX protein expressions in the hippocampal CA1 region. Furthermore, pretreatment of rolipram, a PDE4 inhibitor, rescued propofol induced inhibition of CA1 LTP and the impairment of hippocampus-dependent memory formation in rats. Thus, our results suggest that reduced levels of cAMP by increasing PDE4 activity and PDE4AX protein expressions in the hippocampal CA1 region plays an important role in the propofol-induced amnesia.
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Affiliation(s)
- Weiwei Li
- Department of Anesthesiology, Changzheng Hospital, Second Military Medical University, Shanghai, China.,Institutes of Brain Science & State Key Laboratory of Medical Neurobiology, Zhongshan Hospital, Fudan University, Shanghai, China.,Department of Anesthesiology, Xinhua Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Lingling Yu
- Department of Critical Care Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xiaodi Yan
- Department of Anesthesiology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Linlin Cai
- Department of Anesthesiology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Li Wan
- Institutes of Brain Science & State Key Laboratory of Medical Neurobiology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Qinyu Teng
- Department of Anesthesiology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Yonghua Li
- Department of Anesthesiology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Yun Wang
- Institutes of Brain Science & State Key Laboratory of Medical Neurobiology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Haitao Xu
- Department of Anesthesiology, Changzheng Hospital, Second Military Medical University, Shanghai, China
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14
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Kumari P, Kauser H, Wadhwa M, Roy K, Alam S, Sahu S, Kishore K, Ray K, Panjwani U. Hypobaric hypoxia impairs cued and contextual fear memory in rats. Brain Res 2018; 1692:118-133. [PMID: 29705603 DOI: 10.1016/j.brainres.2018.04.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 04/17/2018] [Accepted: 04/23/2018] [Indexed: 01/13/2023]
Abstract
Fear memory is essential for survival, and its dysregulation leads to disorders. High altitude hypobaric hypoxia (HH) is known to induce cognitive decline. However, its effect on fear memory is still an enigma. We aimed to investigate the temporal effect of HH on fear conditioning and the underlying mechanism. Adult male Sprague-Dawley rats were trained for fear conditioning and exposed to simulated HH equivalent to 25,000 ft for different durations (1, 3, 7, 14 and 21 days). Subsequently, rats were tested for cued and contextual fear conditioning. Neuronal morphology, apoptosis and DNA fragmentation were studied in the medial prefrontal cortex (mPFC), hippocampus and basolateral amygdala (BLA). We observed significant deficit in cued and contextual fear acquisition (at 1, 3 and 7 days) and consolidation (cued at 1 and 3 days and contextual fear at 1, 3 and 7 days) under HH. HH exposure with retraining showed the earlier restoration of contextual fear memory. Further, we found a gradual increase in the number of pyknotic and apoptotic neurons together with the increase in DNA fragmentation in mPFC, hippocampus, and BLA up to 7 days of HH exposure. The present study concludes that HH exposure equivalent to 25,000 ft induced cued and contextual fear memory deficit (acquisition and consolidation) which is found to be correlated with the neurodegenerative changes in the limbic brain regions.
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Affiliation(s)
- Punita Kumari
- Defence Institute of Physiology and Allied Sciences (DIPAS), Defence Research and Development Organization (DRDO), Lucknow Road, Timarpur, Delhi 110054, India
| | - Hina Kauser
- Defence Institute of Physiology and Allied Sciences (DIPAS), Defence Research and Development Organization (DRDO), Lucknow Road, Timarpur, Delhi 110054, India
| | - Meetu Wadhwa
- Defence Institute of Physiology and Allied Sciences (DIPAS), Defence Research and Development Organization (DRDO), Lucknow Road, Timarpur, Delhi 110054, India
| | - Koustav Roy
- Defence Institute of Physiology and Allied Sciences (DIPAS), Defence Research and Development Organization (DRDO), Lucknow Road, Timarpur, Delhi 110054, India
| | - Shahnawaz Alam
- Defence Institute of Physiology and Allied Sciences (DIPAS), Defence Research and Development Organization (DRDO), Lucknow Road, Timarpur, Delhi 110054, India
| | - Surajit Sahu
- Defence Institute of Physiology and Allied Sciences (DIPAS), Defence Research and Development Organization (DRDO), Lucknow Road, Timarpur, Delhi 110054, India
| | - Krishna Kishore
- Defence Institute of Physiology and Allied Sciences (DIPAS), Defence Research and Development Organization (DRDO), Lucknow Road, Timarpur, Delhi 110054, India
| | - Koushik Ray
- Defence Institute of Physiology and Allied Sciences (DIPAS), Defence Research and Development Organization (DRDO), Lucknow Road, Timarpur, Delhi 110054, India
| | - Usha Panjwani
- Defence Institute of Physiology and Allied Sciences (DIPAS), Defence Research and Development Organization (DRDO), Lucknow Road, Timarpur, Delhi 110054, India.
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15
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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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Johnson LR. Editorial: How Fear and Stress Shape the Mind. Front Behav Neurosci 2016; 10:24. [PMID: 27013997 PMCID: PMC4782011 DOI: 10.3389/fnbeh.2016.00024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 02/04/2016] [Indexed: 12/22/2022] Open
Affiliation(s)
- Luke R Johnson
- School of Psychology and Counselling, Translational Research Institute, Institute of Health and Biomedical Innervation, Queensland University of TechnologyBrisbane, QLD, Australia; Department of Psychiatry, Center for the Study of Traumatic Stress, Uniformed Services University School of MedicineBethesda, MD, USA
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17
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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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18
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High-dose corticosterone after fear conditioning selectively suppresses fear renewal by reducing anxiety-like response. Pharmacol Biochem Behav 2014; 124:188-95. [PMID: 24933336 DOI: 10.1016/j.pbb.2014.06.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Revised: 05/22/2014] [Accepted: 06/07/2014] [Indexed: 11/21/2022]
Abstract
Exposure therapy is widely used to treat anxiety disorders, including posttraumatic stress disorder (PTSD). However, preventing the return of fear is still a major challenge after this behavioral treatment. An increasing number of studies suggest that high-dose glucocorticoid treatment immediately after trauma can alleviate the symptoms of PTSD in humans. Unknown is whether high-dose glucocorticoid treatment following fear conditioning suppresses the return of fear. In the present study, a typical fear renewal paradigm (AAB) was used, in which the fear response to an auditory cue can be restored in a novel context (context B) when both training and extinction occur in the same context (context A). We trained rats for auditory fear conditioning and administered corticosterone (CORT; 5 and 25mg/kg, i.p.) or vehicle with different delays (1 and 24h). Forty-eight hours after drug injection, extinction was conducted with no drug in the training context, followed by a test of tone-induced freezing behavior in the same (AAA) or a shifted (AAB) context. Both immediate and delayed administration of high-dose CORT after fear conditioning reduced fear renewal. To examine the anxiolytic effect of CORT, independent rats were trained for cued or contextual fear conditioning, followed by an injection of CORT (5 and 25mg/kg, i.p.) or vehicle at a 1 or 24h delay. One week later, anxiety-like behavior was assessed in the elevated plus maze (EPM) before and after fear expression. We found that high-dose CORT decreased anxiety-like behavior without changing tone- or context-induced freezing. These findings indicate that a single high-dose CORT administration given after fear conditioning may selectively suppress fear renewal by reducing anxiety-like behavior and not by altering the consolidation, retrieval, or extinction of fear memory.
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19
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Federighi G, Traina G, Macchi M, Ciampini C, Bernardi R, Baldi E, Bucherelli C, Brunelli M, Scuri R. Modulation of gene expression in contextual fear conditioning in the rat. PLoS One 2013; 8:e80037. [PMID: 24278235 PMCID: PMC3837011 DOI: 10.1371/journal.pone.0080037] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 09/27/2013] [Indexed: 01/30/2023] Open
Abstract
In contextual fear conditioning (CFC) a single training leads to long-term memory of context-aversive electrical foot-shocks association. Mid-temporal regions of the brain of trained and naive rats were obtained 2 days after conditioning and screened by two-directional suppression subtractive hybridization. A pool of differentially expressed genes was identified and some of them were randomly selected and confirmed with qRT-PCR assay. These transcripts showed high homology for rat gene sequences coding for proteins involved in different cellular processes. The expression of the selected transcripts was also tested in rats which had freely explored the experimental apparatus (exploration) and in rats to which the same number of aversive shocks had been administered in the same apparatus, but temporally compressed so as to make the association between painful stimuli and the apparatus difficult (shock-only). Some genes resulted differentially expressed only in the rats subjected to CFC, others only in exploration or shock-only rats, whereas the gene coding for translocase of outer mitochondrial membrane 20 protein and nardilysin were differentially expressed in both CFC and exploration rats. For example, the expression of stathmin 1 whose transcripts resulted up regulated was also tested to evaluate the transduction and protein localization after conditioning.
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Affiliation(s)
- Giuseppe Federighi
- Dipartimento di Ricerca Traslazionale e Delle Nuove Tecnologie in Medicina e Chirurgia, Unità di Fisiologia, Università di Pisa, Pisa, Italy
| | - Giovanna Traina
- Dipartimento di Scienze Economico-Estimative e degli Alimenti, Sezione di Chimica Bromatologica, Biochimica, Fisiologia e Nutrizione, Università degli Studi di Perugia, Perugia, Italy
| | - Monica Macchi
- Dipartimento di Biologia, Università di Pisa, Pisa, Italy
| | - Cristina Ciampini
- Dipartimento di Ricerca Traslazionale e Delle Nuove Tecnologie in Medicina e Chirurgia, Unità di Fisiologia, Università di Pisa, Pisa, Italy
| | - Rodolfo Bernardi
- Dipartimento di Scienze Agrarie, Genetica Alimentari e Agro-Ambientali, Università di Pisa, Pisa, Italy
| | - Elisabetta Baldi
- Dipartimento di Scienze Fisiologiche, Università di Firenze, Firenze, Italy
| | - Corrado Bucherelli
- Dipartimento di Scienze Fisiologiche, Università di Firenze, Firenze, Italy
| | | | - Rossana Scuri
- Dipartimento di Ricerca Traslazionale e Delle Nuove Tecnologie in Medicina e Chirurgia, Unità di Fisiologia, Università di Pisa, Pisa, Italy
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20
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Reichelt AC, Lee JLC. Memory reconsolidation in aversive and appetitive settings. Front Behav Neurosci 2013; 7:118. [PMID: 24058336 PMCID: PMC3766793 DOI: 10.3389/fnbeh.2013.00118] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 08/20/2013] [Indexed: 11/16/2022] Open
Abstract
Memory reconsolidation has been observed across species and in a number of behavioral paradigms. The majority of memory reconsolidation studies have been carried out in Pavlovian fear conditioning and other aversive memory settings, with potential implications for the treatment of post-traumatic stress disorder. However, there is a growing literature on memory reconsolidation in appetitive reward-related memory paradigms, including translational models of drug addiction. While there appears to be substantial similarity in the basic phenomenon and underlying mechanisms of memory reconsolidation across unconditioned stimulus valence, there are also notable discrepancies. These arise both when comparing aversive to appetitive paradigms and also across different paradigms within the same valence of memory. We review the demonstration of memory reconsolidation across different aversive and appetitive memory paradigms, the commonalities and differences in underlying mechanisms and the conditions under which each memory undergoes reconsolidation. We focus particularly on whether principles derived from the aversive literature are applicable to appetitive settings, and also whether the expanding literature in appetitive paradigms is informative for fear memory reconsolidation.
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Affiliation(s)
- Amy C Reichelt
- School of Psychology, University of Birmingham Birmingham, UK
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