1
|
Subramanian R, Bauman A, Carpenter O, Cho C, Coste G, Dam A, Drake K, Ehnstrom S, Fitzgerald N, Jenkins A, Koolpe H, Liu R, Paserman T, Petersen D, Chavez DS, Rozental S, Thompson H, Tsukuda T, Zweig S, Gall M, Zupan B, Bergstrom H. An Infralimbic Cortex Neuronal Ensemble Encoded During Learning Attenuates Fear Generalization Expression. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.18.608308. [PMID: 39229064 PMCID: PMC11370439 DOI: 10.1101/2024.08.18.608308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
Generalization allows for experience to flexibly guide behavior when conditions change. A basic physical unit of memory storage and expression in the brain are sparse, distributed groups of neurons known as ensembles (i.e., the engram). The infralimbic (IL) subregion of the ventral medial prefrontal cortex plays a key role in modulating conditioned defensive responses. How IL neuronal ensembles established during learning contribute to generalized responses is unknown. In this set of experiments, generalization was tested in male and female mice by presenting a novel, ambiguous, tone generalization stimulus following Pavlovian defensive (fear) conditioning. The first experiment was designed to test a role for IL in generalization using chemogenetic manipulations. Results show IL bidirectionally regulates defensive behavior. IL silencing promotes a switch in defensive state from vigilant scanning to generalized freezing, while IL stimulation reduces freezing in favor of scanning. Leveraging activity-dependent tagging technology (ArcCreERT2 x eYFP system), a neuronal ensemble, preferentially located in IL superficial layer 2/3, was associated with the generalization stimulus. Remarkably, in the identical discrete location, fewer reactivated neurons were associated with the generalization stimulus at the remote timepoint (30 days) following learning. When an IL neuronal ensemble established during learning was selectively chemogenetically silenced, generalization increased. Conversely, IL neuronal ensemble stimulation reduced generalization. Overall, these data identify a crucial role for IL in suppressing generalized responses. Further, we uncover an IL neuronal ensemble, formed during learning, functions to later attenuate the expression of generalization in the presence of ambiguous threat stimuli.
Collapse
Affiliation(s)
- Rajani Subramanian
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Avery Bauman
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Olivia Carpenter
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Chris Cho
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Gabrielle Coste
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Ahona Dam
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Kasey Drake
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Sara Ehnstrom
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Naomi Fitzgerald
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Abigail Jenkins
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Hannah Koolpe
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Runqi Liu
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Tamar Paserman
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - David Petersen
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Diego Scala Chavez
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Stefano Rozental
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Hannah Thompson
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Tyler Tsukuda
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Sasha Zweig
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Megan Gall
- Department of Biology, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Bojana Zupan
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| | - Hadley Bergstrom
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie NY 12603 USA
| |
Collapse
|
2
|
Dong X, Wang Y, Liu Y, Li Y. Fear generalization modulated by shock intensity and protein synthesis inhibitor. Psychopharmacology (Berl) 2024:10.1007/s00213-024-06662-1. [PMID: 39105767 DOI: 10.1007/s00213-024-06662-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Accepted: 07/29/2024] [Indexed: 08/07/2024]
Abstract
RATIONALE Maladaptive fear responses, including sensitized threat reactions and overgeneralization, contribute to anxiety disorders such as generalized anxiety disorder and post-traumatic stress disorder. Although stress intensity influences the generation and extent of these maladaptive fears, the underlying mechanisms remain unclear. OBJECTIVES The present study examined whether varying footshock stress intensity and inhibition of protein synthesis have differential effect on fear sensitization and generalization in mice. METHODS Mice were subjected to a classic fear conditioning protocol involving five different levels of footshock intensities. Prior to fear acquisition, the protein synthesis inhibitor cycloheximide (CHX) was administered intraperitoneally. Fear sensitization to white noise and fear generalization to tones with frequencies differing from the conditioned tone were assessed at either 2 or 4 days after fear acquisition. RESULTS The results showed that, although varying shock intensities (except the lowest) led to a similar pattern of increased freezing during auditory cues in fear acquisition, the extent of both fear sensitization and generalization increased with the intensity of the footshock in the following days. As shock intensities increased, there was a proportional rise in sensitized fear to white noise and generalized freezing to tones with frequencies progressively closer to the conditioned stimulus. Mildest shocks did not induce discriminative conditioned fear memory, whereas the most intense shocks led to pronounced fear generalization. Administration of CHX before fear acquisition did not affect sensitized fear but reduced generalization of freezing to tones dissimilar from the conditioned stimulus in the group exposed to the most intense shock. CONCLUSIONS Our results suggest that maladaptive fear responses elicited by varying stress intensities exhibit distinct characteristics. The effect of CHX to prevent overgeneralization without affecting discriminative fear memory points to potential therapeutic approaches for fear-related disorders, suggesting the possibility of mitigating overgeneralization while preserving necessary fear discrimination.
Collapse
Affiliation(s)
- Xinwen Dong
- Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
| | - Yunyun Wang
- Department of Neuroendocrine Pharmacology, School of Pharmacy, China Medical University, Shenyang, China
| | - Yudan Liu
- Department of Neuroendocrine Pharmacology, School of Pharmacy, China Medical University, Shenyang, China
| | - Yonghui Li
- Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
3
|
Bihorac J, Salem Y, Lückemann L, Schedlowski M, Doenlen R, Engler H, Mark MD, Dombrowski K, Spoida K, Hadamitzky M. Investigations on the Ability of the Insular Cortex to Process Peripheral Immunosuppression. J Neuroimmune Pharmacol 2024; 19:40. [PMID: 39078442 PMCID: PMC11289148 DOI: 10.1007/s11481-024-10143-9] [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: 02/22/2024] [Accepted: 07/14/2024] [Indexed: 07/31/2024]
Abstract
The brain and immune system communicate through complex bidirectional pathways, but the specificity by which the brain perceives or even remembers alterations in immune homeostasis is still poorly understood. Recent data revealed that immune-related information under peripheral inflammatory conditions, termed as "immunengram", were represented in specific neuronal ensembles in the insular cortex (IC). Chemogenetic reactivation of these neuronal ensembles was sufficient to retrieve the inflammatory stages, indicating that the brain can store and retrieve specific immune responses. Against this background, the current approach was designed to investigate the ability of the IC to process states of immunosuppression pharmacologically induced by the mechanistic target of rapamycin (mTOR) inhibitor rapamycin. We here show that the IC perceives the initial state of immunosuppression, reflected by increased deep-brain electroencephalography (EEG) activity during acute immunosuppressive drug treatment. Following an experienced period of immunosuppression, though, diminished splenic cytokine production as formerly induced by rapamycin could not be reinstated by nonspecific chemogenetic activation or inhibition of the IC. These findings suggest that the information of a past, or experienced status of pharmacologically induced immunosuppression is not represented in the IC. Together, the present work extends the view of immune-to-brain communication during the states of peripheral immunosuppression and foster the prominent role of the IC for interoception.
Collapse
Affiliation(s)
- Julia Bihorac
- Institute of Medical Psychology and Behavioral Immunobiology, Center for Translational Neuro- Behavioral Sciences (C-TNBS), University Hospital Essen, University of Duisburg-Essen, Essen, 45147, Germany
| | - Yasmin Salem
- Institute of Medical Psychology and Behavioral Immunobiology, Center for Translational Neuro- Behavioral Sciences (C-TNBS), University Hospital Essen, University of Duisburg-Essen, Essen, 45147, Germany
| | - Laura Lückemann
- Institute of Medical Psychology and Behavioral Immunobiology, Center for Translational Neuro- Behavioral Sciences (C-TNBS), University Hospital Essen, University of Duisburg-Essen, Essen, 45147, Germany
| | - Manfred Schedlowski
- Institute of Medical Psychology and Behavioral Immunobiology, Center for Translational Neuro- Behavioral Sciences (C-TNBS), University Hospital Essen, University of Duisburg-Essen, Essen, 45147, Germany
- Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Raphael Doenlen
- Center of Phenogenomics, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Harald Engler
- Institute of Medical Psychology and Behavioral Immunobiology, Center for Translational Neuro- Behavioral Sciences (C-TNBS), University Hospital Essen, University of Duisburg-Essen, Essen, 45147, Germany
| | - Melanie D Mark
- Behavioral Neuroscience, Faculty for Biology and Biotechnology, Ruhr-University Bochum, Bochum, Germany
| | - Kirsten Dombrowski
- Institute of Medical Psychology and Behavioral Immunobiology, Center for Translational Neuro- Behavioral Sciences (C-TNBS), University Hospital Essen, University of Duisburg-Essen, Essen, 45147, Germany
| | - Katharina Spoida
- Department of General Zoology and Neurobiology, Ruhr-University Bochum, Bochum, Germany
| | - Martin Hadamitzky
- Institute of Medical Psychology and Behavioral Immunobiology, Center for Translational Neuro- Behavioral Sciences (C-TNBS), University Hospital Essen, University of Duisburg-Essen, Essen, 45147, Germany.
| |
Collapse
|
4
|
Rezayof A, Ghasemzadeh Z, Sahafi OH. Addictive drugs modify neurogenesis, synaptogenesis and synaptic plasticity to impair memory formation through neurotransmitter imbalances and signaling dysfunction. Neurochem Int 2023; 169:105572. [PMID: 37423274 DOI: 10.1016/j.neuint.2023.105572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 07/01/2023] [Accepted: 07/05/2023] [Indexed: 07/11/2023]
Abstract
Drug abuse changes neurophysiological functions at multiple cellular and molecular levels in the addicted brain. Well-supported scientific evidence suggests that drugs negatively affect memory formation, decision-making and inhibition, and emotional and cognitive behaviors. The mesocorticolimbic brain regions are involved in reward-related learning and habitual drug-seeking/taking behaviors to develop physiological and psychological dependence on the drugs. This review highlights the importance of specific drug-induced chemical imbalances resulting in memory impairment through various neurotransmitter receptor-mediated signaling pathways. The mesocorticolimbic modifications in the expression levels of brain-derived neurotrophic factor (BDNF) and the cAMP-response element binding protein (CREB) impair reward-related memory formation following drug abuse. The contributions of protein kinases and microRNAs (miRNAs), along with the transcriptional and epigenetic regulation have also been considered in memory impairment underlying drug addiction. Overall, we integrate the research on various types of drug-induced memory impairment in distinguished brain regions and provide a comprehensive review with clinical implications addressing the upcoming studies.
Collapse
Affiliation(s)
- Ameneh Rezayof
- Department of Animal Biology, School of Biology, College of Science, University of Tehran, Tehran, Iran.
| | - Zahra Ghasemzadeh
- Department of Animal Biology, School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Oveis Hosseinzadeh Sahafi
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| |
Collapse
|
5
|
Venkataraman A, Dias BG. Expanding the canon: An inclusive neurobiology of thalamic and subthalamic fear circuits. Neuropharmacology 2023; 226:109380. [PMID: 36572176 PMCID: PMC9984284 DOI: 10.1016/j.neuropharm.2022.109380] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 12/09/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022]
Abstract
Appropriate expression of fear in the face of threats in the environment is essential for survival. The sustained expression of fear in the absence of threat signals is a central pathological feature of trauma- and anxiety-related disorders. Our understanding of the neural circuitry that controls fear inhibition coalesces around the amygdala, hippocampus, and prefrontal cortex. By discussing thalamic and sub-thalamic influences on fear-related learning and expression in this review, we suggest a more inclusive neurobiological framework that expands our canonical view of fear. First, we visit how fear-related learning and expression is influenced by the aforementioned canonical brain regions. Next, we review emerging data that shed light on new roles for thalamic and subthalamic nuclei in fear-related learning and expression. Then, we highlight how these neuroanatomical hubs can modulate fear via integration of sensory and salient stimuli, gating information flow and calibrating behavioral responses, as well as maintaining and updating memory representations. Finally, we propose that the presence of this thalamic and sub-thalamic neuroanatomy in parallel with the tripartite prefrontal cortex-amygdala-hippocampus circuit allows for dynamic modulation of information based on interoceptive and exteroceptive signals. This article is part of the Special Issue on "Fear, Anxiety and PTSD".
Collapse
Affiliation(s)
- Archana Venkataraman
- Department of Cellular & Molecular Pharmacology, University of San Francisco, San Francisco, CA, United States
| | - Brian George Dias
- Department of Pediatrics, Keck School of Medicine of USC, Los Angeles, CA, United States; Division of Endocrinology, Children's Hospital Los Angeles, Los Angeles, CA, United States; Developmental Neuroscience and Neurogenetics Program, The Saban Research Institute, Los Angeles, CA, United States.
| |
Collapse
|
6
|
Cincotta C, Ruesch E, Senne R, Ramirez S. Hippocampal fear engrams modulate ethanol-induced maladaptive contextual generalization in mice. Hippocampus 2022; 32:707-715. [PMID: 35950345 DOI: 10.1002/hipo.23463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 06/27/2022] [Accepted: 07/16/2022] [Indexed: 11/09/2022]
Abstract
The compounding symptomatology of alcohol use disorder (AUD) and co-occurring mental health disorders gives rise to interactions of maladaptive neurobiological processes, the etiology of which are elusive. Here, we devised an optogenetic strategy aimed at rescuing maladaptive fear processing in male c57BL/6 mice that underwent a chronic ethanol administration and forced abstinence paradigm. In the first experiment, we confirmed that fear acquisition and maladaptive contextual generalization was potentiated in ethanol-exposed mice during fear conditioning and exposure to a novel environment, respectively. In the second experiment, using an activity-dependent tet-tag system, we labeled the neural ensemble selectively activated by contextual fear conditioning in the dorsal hippocampus with an inhibitory opsin to attenuate behavioral dysfunctions resulting from ethanol exposure. We found that acute optogenetic perturbations during exposure to a novel environment suppressed maladaptive generalization in ethanol-exposed mice. These results provide further evidence for a crucial link between ethanol exposure and impaired fear memory processing by providing cellular and behavioral insights into the neural circuitry underlying AUD and maladaptive fear processing.
Collapse
Affiliation(s)
- Christine Cincotta
- Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, USA
| | - Evan Ruesch
- Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, USA
| | - Ryan Senne
- Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, USA
| | - Steve Ramirez
- Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, USA
| |
Collapse
|
7
|
Lawson K, Scarlata MJ, Cho WC, Mangan C, Petersen D, Thompson HM, Ehnstrom S, Mousley AL, Bezek JL, Bergstrom HC. Adolescence alcohol exposure impairs fear extinction and alters medial prefrontal cortex plasticity. Neuropharmacology 2022; 211:109048. [PMID: 35364101 PMCID: PMC9067297 DOI: 10.1016/j.neuropharm.2022.109048] [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: 11/09/2021] [Revised: 02/26/2022] [Accepted: 03/26/2022] [Indexed: 10/18/2022]
Abstract
After experiencing a traumatic event people often turn to alcohol to cope with symptoms. In those with post-traumatic stress disorder (PTSD) and a co-occurring alcohol use disorder (AUD), PTSD symptoms can worsen, suggesting that alcohol changes how traumatic memory is expressed. The objective of this series of experiments is to identify how alcohol drinking (EtOH), following cued fear conditioning and extinction, impacts fear expression in mice. Molecular (activity-regulated cytoskeleton-associated protein, Arc/arg3.1) and structural (dendrite and spine morphometry) markers of neuronal plasticity were measured following remote extinction retrieval. Mouse age (adolescent and adult) and sex were included as interacting variables in a full factorial design. Females drank more EtOH than males and adolescents drank more EtOH than adults. Adolescent females escalated EtOH intake across drinking days. Adolescent drinkers exhibited more conditioned freezing during extinction retrieval, an effect that persisted for at least 20 days. Heightened cued freezing in the adolescent group was associated with greater Arc/arg3.1 expression in layer (L) 2/3 prelimbic (PL) cortex, greater spine density, and reduced basal dendrite complexity. In adults, drinking was associated with reduced L2/3 infralimbic (IL) Arc expression but no behavioral differences. Few sex interactions were uncovered throughout. Overall, these data identify prolonged age-related differences in alcohol-induced fear extinction impairment and medial prefrontal cortex neuroadaptations.
Collapse
Affiliation(s)
- K Lawson
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, NY, USA
| | - M J Scarlata
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, NY, USA
| | - W C Cho
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, NY, USA
| | - C Mangan
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, NY, USA
| | - D Petersen
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, NY, USA
| | - H M Thompson
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, NY, USA
| | - S Ehnstrom
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, NY, USA
| | - A L Mousley
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, NY, USA
| | - J L Bezek
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, NY, USA
| | - H C Bergstrom
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, NY, USA.
| |
Collapse
|
8
|
Functional ultrasound imaging of recent and remote memory recall in the associative fear neural network in mice. Behav Brain Res 2022; 428:113862. [DOI: 10.1016/j.bbr.2022.113862] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 03/20/2022] [Accepted: 03/25/2022] [Indexed: 11/21/2022]
|
9
|
Chemogenetics as a neuromodulatory approach to treating neuropsychiatric diseases and disorders. Mol Ther 2022; 30:990-1005. [PMID: 34861415 PMCID: PMC8899595 DOI: 10.1016/j.ymthe.2021.11.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 11/12/2021] [Accepted: 11/29/2021] [Indexed: 01/01/2023] Open
Abstract
Chemogenetics enables precise, non-invasive, and reversible modulation of neural activity via the activation of engineered receptors that are pharmacologically selective to endogenous or exogenous ligands. With recent advances in therapeutic gene delivery, chemogenetics is poised to support novel interventions against neuropsychiatric diseases and disorders. To evaluate its translational potential, we performed a scoping review of applications of chemogenetics that led to the reversal of molecular and behavioral deficits in studies relevant to neuropsychiatric diseases and disorders. In this review, we present these findings and discuss the potential and challenges for using chemogenetics as a precision medicine-based neuromodulation strategy.
Collapse
|
10
|
An epigenetic mechanism for over-consolidation of fear memories. Mol Psychiatry 2022; 27:4893-4904. [PMID: 36127428 PMCID: PMC9763112 DOI: 10.1038/s41380-022-01758-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 08/09/2022] [Accepted: 08/18/2022] [Indexed: 01/14/2023]
Abstract
Excessive fear is a hallmark of anxiety disorders, a major cause of disease burden worldwide. Substantial evidence supports a role of prefrontal cortex-amygdala circuits in the regulation of fear and anxiety, but the molecular mechanisms that regulate their activity remain poorly understood. Here, we show that downregulation of the histone methyltransferase PRDM2 in the dorsomedial prefrontal cortex enhances fear expression by modulating fear memory consolidation. We further show that Prdm2 knock-down (KD) in neurons that project from the dorsomedial prefrontal cortex to the basolateral amygdala (dmPFC-BLA) promotes increased fear expression. Prdm2 KD in the dmPFC-BLA circuit also resulted in increased expression of genes involved in synaptogenesis, suggesting that Prdm2 KD modulates consolidation of conditioned fear by modifying synaptic strength at dmPFC-BLA projection targets. Consistent with an enhanced synaptic efficacy, we found that dmPFC Prdm2 KD increased glutamatergic release probability in the BLA and increased the activity of BLA neurons in response to fear-associated cues. Together, our findings provide a new molecular mechanism for excessive fear responses, wherein PRDM2 modulates the dmPFC -BLA circuit through specific transcriptomic changes.
Collapse
|
11
|
Nett KE, LaLumiere RT. Infralimbic cortex functioning across motivated behaviors: Can the differences be reconciled? Neurosci Biobehav Rev 2021; 131:704-721. [PMID: 34624366 PMCID: PMC8642304 DOI: 10.1016/j.neubiorev.2021.10.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 09/10/2021] [Accepted: 10/02/2021] [Indexed: 10/20/2022]
Abstract
The rodent infralimbic cortex (IL) is implicated in higher order executive functions such as reward seeking and flexible decision making. However, the precise nature of its role in these processes is unclear. Early evidence indicated that the IL promotes the extinction and ongoing inhibition of fear conditioning and cocaine seeking. However, evidence spanning other behavioral domains, such as natural reward seeking and habit-based learning, suggests a more nuanced understanding of IL function. As techniques have advanced and more studies have examined IL function, identifying a unifying explanation for its behavioral function has become increasingly difficult. Here, we discuss evidence of IL function across motivated behaviors, including associative learning, drug seeking, natural reward seeking, and goal-directed versus habit-based behaviors, and emphasize how context-specific encoding and heterogeneous IL neuronal populations may underlie seemingly conflicting findings in the literature. Together, the evidence suggests that a major IL function is to facilitate the encoding and updating of contingencies between cues and behaviors to guide subsequent behaviors.
Collapse
Affiliation(s)
- Kelle E Nett
- Interdisciplinary Neuroscience Program, University of Iowa, Iowa City, IA 52242, United States.
| | - Ryan T LaLumiere
- Interdisciplinary Neuroscience Program, University of Iowa, Iowa City, IA 52242, United States; Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA 52242, United States; Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242, United States
| |
Collapse
|
12
|
McCool BA. Ethanol modulation of cortico-basolateral amygdala circuits: Neurophysiology and behavior. Neuropharmacology 2021; 197:108750. [PMID: 34371080 DOI: 10.1016/j.neuropharm.2021.108750] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 07/22/2021] [Accepted: 08/05/2021] [Indexed: 12/19/2022]
Abstract
This review highlights literature relating the anatomy, physiology, and behavioral contributions by projections between rodent prefrontal cortical areas and the basolateral amygdala. These projections are robustly modulated by both environmental experience and exposure to drugs of abuse including ethanol. Recent literature relating optogenetic and chemogenetic dissection of these circuits within behavior both compliments and occasionally challenges roles defined by more traditional pharmacological or lesion-based approaches. In particular, cortico-amygdala circuits help control both aversive and reward-seeking. Exposure to pathology-producing environments or abused drugs dysregulates the relative 'balance' of these outcomes. Modern circuit-based approaches have also shown that overlapping populations of neurons within a given brain region frequently govern both aversion and reward-seeking. In addition, these circuits often dramatically influence 'local' cortical or basolateral amygdala excitatory or inhibitory circuits. Our understanding of these neurobiological processes, particularly in relation to ethanol research, has just begun and represents a significant opportunity.
Collapse
Affiliation(s)
- Brian A McCool
- Department of Physiology & Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC, USA.
| |
Collapse
|
13
|
Saul’skaya NB, Marchuk OE, Puzanova MA, Trofimova NA. Activation of Serotonin System in the Medial Prefrontal Cortex by Sound Signals of Danger. NEUROCHEM J+ 2020. [DOI: 10.1134/s181971242004008x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
14
|
Infralimbic cortex controls fear memory generalization and susceptibility to extinction during consolidation. Sci Rep 2020; 10:15827. [PMID: 32985565 PMCID: PMC7522076 DOI: 10.1038/s41598-020-72856-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 09/03/2020] [Indexed: 01/22/2023] Open
Abstract
Lesioning or inactivating the infralimbic (IL) subregion of the medial prefrontal cortex before acquisition produces more generalized and extinction-resistant fear memories. However, whether and how it modulates memory specificity and extinction susceptibility while consolidation takes place is still unknown. The present study aims to investigate these questions using muscimol-induced temporary inactivation and anisomycin-induced protein synthesis inhibition in the rat IL following contextual fear conditioning. Results indicate that the IL activity immediately after acquisition, but not six hours later, controls memory generalization over a week, regardless of its strength. Such IL function depends on the context-shock pairing since muscimol induced no changes in animals exposed to immediate shocks or the conditioning context only. Animals in which the IL was inactivated during consolidation extinguished similarly to controls within the session but were unable to recall the extinction memory the following day. Noteworthy, these post-acquisition IL inactivation-induced effects were not associated with changes in anxiety, as assessed in the elevated plus-maze test. Anisomycin results indicate that the IL protein synthesis during consolidation contributes more to producing extinction-sensitive fear memories than memory specificity. Collectively, present results provide evidence for the IL's role in controlling generalization and susceptibility to extinction during fear memory consolidation.
Collapse
|
15
|
Cincotta C, Murawski NJ, Grella SL, McKissick O, Doucette E, Ramirez S. Chronic activation of fear engrams induces extinction-like behavior in ethanol-exposed mice. Hippocampus 2020; 31:3-10. [PMID: 32946184 DOI: 10.1002/hipo.23263] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 08/21/2020] [Accepted: 08/30/2020] [Indexed: 01/31/2023]
Abstract
Alcohol withdrawal directly impacts the brain's stress and memory systems, which may underlie individual susceptibility to persistent drug and alcohol-seeking behaviors. Numerous studies demonstrate that forced alcohol abstinence, which may lead to withdrawal, can impair fear-related memory processes in rodents such as extinction learning; however, the underlying neural circuits mediating these impairments remain elusive. Here, we tested an optogenetic strategy aimed at mitigating fear extinction retrieval impairments in male c57BL/6 mice following exposure to alcohol (i.e., ethanol) and forced abstinence. In the first experiment, extensive behavioral extinction training in a fear-conditioned context was impaired in ethanol-exposed mice compared to controls. In the second experiment, neuronal ensembles processing a contextual fear memory in the dorsal hippocampus were tagged and optogenetically reactivated repeatedly in a distinct context in ethanol-exposed and control mice. Chronic activation of these cells resulted in a context-specific, extinction-like reduction in fear responses in both control and ethanol-exposed mice. These findings suggest that while ethanol can impair the retrieval an extinction memory, optogenetic manipulation of a fear engram is sufficient to induce an extinction-like reduction in fear responses.
Collapse
Affiliation(s)
- Christine Cincotta
- Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, USA
| | | | - Stephanie L Grella
- Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, USA
| | - Olivia McKissick
- Department of Neuroscience, Brown University, Providence, Rhode Island, USA
| | - Emily Doucette
- Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, USA
| | - Steve Ramirez
- Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, USA
| |
Collapse
|
16
|
Paizanis E, Crotti M, Petit A, Règue M, Beray-Berthat V, Noble F, Lanfumey L, Mongeau R. Effects of Alcohol and Cocaine in a Mutant Mouse Model of Predisposition to Post-Traumatic Stress Disorder. Front Pharmacol 2020; 11:623. [PMID: 32477119 PMCID: PMC7232567 DOI: 10.3389/fphar.2020.00623] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 04/20/2020] [Indexed: 01/14/2023] Open
Abstract
Comorbidity between drug abuse and post-traumatic stress disorder (PTSD), a stress-related dysregulation of fear responses, is very high. While some drugs are known to increase fear and anxiety, there are only few data regarding interactions between voluntary drug consumption and fear memory. The spontaneous chronic consumption of either alcohol or cocaine under a 3-week free-choice progressive paradigm of alcohol (3/6/10%) or cocaine (0.2/0.4/0.6 mg/ml), was assessed in VGV transgenic mice, having full 5-HT2C receptor editing and displaying PTSD-like behaviors. The consequences of these drug consumptions on the potentiated contextual and cued fear conditioning responses of VGV mice were assessed. The effects of drugs on hippocampal brain-derived neurotrophic factor (Bdnf) mRNA were measured as its expression was previously found to be decreased in VGV mice. Chronic alcohol consumption was similar in WT and VGV mice. In the alcohol condition, fear acquisition was not different at the end of the learning session and cue-fear extinction was facilitated. Regarding cocaine, in contrast to WT mice, VGV mice did not increase their drug consumption along with increasing doses, an effect that might be related with enhanced drug stimuli discrimination via increased 5-HT2C receptors. Cocaine-intake VGV mice did not display the contextual fear generalization usually observed in control VGV mice. In addition, Bdnf expression was upregulated after either chronic alcohol or cocaine intake. Altogether, these results suggest that both chronic alcohol and cocaine voluntary oral consumptions can exert some therapeutic-like effects in a mutant model of PTSD predisposition.
Collapse
Affiliation(s)
- Eleni Paizanis
- University of Caen Normandy, INSERM U1075 COMETE, Caen, France
| | - Michela Crotti
- CNRS ERL 3649 «Pharmacologie et thérapies des addictions» Université Paris Descartes, Inserm UMR-S 1124, Paris, France
| | - Anthony Petit
- IPNP-Université Paris Descartes, INSERM UMR-1266, Paris, France
| | - Mathilde Règue
- IPNP-Université Paris Descartes, INSERM UMR-1266, Paris, France
| | - Virginie Beray-Berthat
- CNRS ERL 3649 «Pharmacologie et thérapies des addictions» Université Paris Descartes, Inserm UMR-S 1124, Paris, France
| | - Florence Noble
- CNRS ERL 3649 «Pharmacologie et thérapies des addictions» Université Paris Descartes, Inserm UMR-S 1124, Paris, France
| | | | - Raymond Mongeau
- CNRS ERL 3649 «Pharmacologie et thérapies des addictions» Université Paris Descartes, Inserm UMR-S 1124, Paris, France
| |
Collapse
|
17
|
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.
Collapse
Affiliation(s)
- Hadley C Bergstrom
- Vassar College, Department of Psychological Science, Program in Neuroscience and Behavior, Poughkeepsie, New York
| |
Collapse
|
18
|
Sangha S, Diehl MM, Bergstrom HC, Drew MR. Know safety, no fear. Neurosci Biobehav Rev 2020; 108:218-230. [PMID: 31738952 PMCID: PMC6981293 DOI: 10.1016/j.neubiorev.2019.11.006] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 09/27/2019] [Accepted: 11/11/2019] [Indexed: 02/08/2023]
Abstract
Every day we are bombarded by stimuli that must be assessed for their potential for harm or benefit. Once a stimulus is learned to predict harm, it can elicit fear responses. Such learning can last a lifetime but is not always beneficial for an organism. For an organism to thrive in its environment, it must know when to engage in defensive, avoidance behaviors and when to engage in non-defensive, approach behaviors. Fear should be suppressed in situations that are not dangerous: when a novel, innocuous stimulus resembles a feared stimulus, when a feared stimulus no longer predicts harm, or when there is an option to avoid harm. A cardinal feature of anxiety disorders is the inability to suppress fear adaptively. In PTSD, for instance, learned fear is expressed inappropriately in safe situations and is resistant to extinction. In this review, we discuss mechanisms of suppressing fear responses during stimulus discrimination, fear extinction, and active avoidance, focusing on the well-studied tripartite circuit consisting of the amygdala, medial prefrontal cortex and hippocampus.
Collapse
Affiliation(s)
- Susan Sangha
- Department of Psychological Sciences and Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, USA.
| | - Maria M Diehl
- Department of Psychological Sciences, Kansas State University, Manhattan, KS, USA.
| | - Hadley C Bergstrom
- Department of Psychological Science, Program in Neuroscience and Behavior, Vassar College, Poughkeepsie, NY, USA.
| | - Michael R Drew
- Center for Learning and Memory and Department of Neuroscience, University of Texas at Austin, Austin, TX, USA.
| |
Collapse
|