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Thomas CMP, Bouton ME, Green JT. Chemogenetic inhibition of the ventral hippocampus but not its direct projection to the prelimbic cortex attenuates context-specific operant responding. Front Behav Neurosci 2024; 18:1310478. [PMID: 38385002 PMCID: PMC10879379 DOI: 10.3389/fnbeh.2024.1310478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 01/24/2024] [Indexed: 02/23/2024] Open
Abstract
Previous work has demonstrated the importance of the prelimbic cortex (PL) in contextual control of operant behavior. However, the associated neural circuitry responsible for providing contextual information to the PL is not well understood. In Pavlovian fear conditioning the ventral hippocampus (vH) and its projection to the PL have been shown to be important in supporting the effects of context on learning. The present experiments used chemogenetic inhibition of the direct vH-PL projection or the vH to determine involvement in expression of context-specific operant behavior. Rats were injected with an inhibitory DREADD (hM4Di) or mCherry-only into the vH, and subsequently trained to perform a lever press response for a food pellet in a distinct context. The DREADD ligand clozapine-n-oxide (CNO) was then delivered directly into the PL (experiment 1) and then systemically (experiment 2) prior to tests of the response in the training context as well as an equally familiar but untrained context. vH (systemic CNO) but not vH-PL (intra-PL CNO) inhibition was found to attenuate operant responding in its acquisition context. A third experiment, using the same rats, showed that chemogenetic inhibition of vH also reduced Pavlovian contextual fear. The present results suggest that multisynapatic connections between the vH and PL may be responsible for integration of contextual information with operant behavior.
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Affiliation(s)
- Callum M. P. Thomas
- Department of Psychological Science, University of Vermont, Burlington, VT, United States
- Neuroscience Graduate Program, University of Vermont, Burlington, VT, United States
| | - Mark E. Bouton
- Department of Psychological Science, University of Vermont, Burlington, VT, United States
| | - John T. Green
- Department of Psychological Science, University of Vermont, Burlington, VT, United States
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Plas SL, Tuna T, Bayer H, Juliano VAL, Sweck SO, Arellano Perez AD, Hassell JE, Maren S. Neural circuits for the adaptive regulation of fear and extinction memory. Front Behav Neurosci 2024; 18:1352797. [PMID: 38370858 PMCID: PMC10869525 DOI: 10.3389/fnbeh.2024.1352797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 01/15/2024] [Indexed: 02/20/2024] Open
Abstract
The regulation of fear memories is critical for adaptive behaviors and dysregulation of these processes is implicated in trauma- and stress-related disorders. Treatments for these disorders include pharmacological interventions as well as exposure-based therapies, which rely upon extinction learning. Considerable attention has been directed toward elucidating the neural mechanisms underlying fear and extinction learning. In this review, we will discuss historic discoveries and emerging evidence on the neural mechanisms of the adaptive regulation of fear and extinction memories. We will focus on neural circuits regulating the acquisition and extinction of Pavlovian fear conditioning in rodent models, particularly the role of the medial prefrontal cortex and hippocampus in the contextual control of extinguished fear memories. We will also consider new work revealing an important role for the thalamic nucleus reuniens in the modulation of prefrontal-hippocampal interactions in extinction learning and memory. Finally, we will explore the effects of stress on this circuit and the clinical implications of these findings.
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Affiliation(s)
- Samantha L. Plas
- Department of Psychological and Brain Sciences, Texas A&M University, College Station, TX, United States
- Institute for Neuroscience, Texas A&M University, College Station, TX, United States
| | - Tuğçe Tuna
- Department of Psychological and Brain Sciences, Texas A&M University, College Station, TX, United States
- Institute for Neuroscience, Texas A&M University, College Station, TX, United States
| | - Hugo Bayer
- Department of Psychological and Brain Sciences, Texas A&M University, College Station, TX, United States
- Institute for Neuroscience, Texas A&M University, College Station, TX, United States
| | - Vitor A. L. Juliano
- Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Samantha O. Sweck
- Department of Psychological and Brain Sciences, Texas A&M University, College Station, TX, United States
- Institute for Neuroscience, Texas A&M University, College Station, TX, United States
| | - Angel D. Arellano Perez
- Department of Psychological and Brain Sciences, Texas A&M University, College Station, TX, United States
| | - James E. Hassell
- Department of Psychological and Brain Sciences, Texas A&M University, College Station, TX, United States
| | - Stephen Maren
- Department of Psychological and Brain Sciences, Texas A&M University, College Station, TX, United States
- Institute for Neuroscience, Texas A&M University, College Station, TX, United States
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Schoenfeld TJ, Rhee D, Smith JA, Padmanaban V, Brockett AT, Jacobs HN, Cameron HA. Rewarded Maze Training Increases Approach Behavior in Rats Through Neurogenesis-Dependent Growth of Ventral Hippocampus-Prelimbic Circuits. BIOLOGICAL PSYCHIATRY GLOBAL OPEN SCIENCE 2023; 3:725-733. [PMID: 37881563 PMCID: PMC10593943 DOI: 10.1016/j.bpsgos.2023.04.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 03/31/2023] [Accepted: 04/06/2023] [Indexed: 10/27/2023] Open
Abstract
Background Learning complex navigation routes increases hippocampal volume in humans, but it is not clear whether this growth impacts behaviors outside the learning situation or what cellular mechanisms are involved. Methods We trained rats with pharmacogenetic suppression of adult neurogenesis and littermate controls in 3 mazes over 3 weeks and tested novelty approach behavior several days after maze exposure. We then measured hippocampus and prelimbic cortex volumes using magnetic resonance imaging and assessed neuronal and astrocyte morphology. Finally, we investigated the activation and behavioral role of the ventral CA1 (vCA1)-to-prelimbic pathway using immediate-early genes and DREADDs (designer receptors exclusively activated by designer drugs). Results Maze training led to volume increase of both the vCA1 region of the hippocampus and the prelimbic region of the neocortex compared with rats that followed fixed paths. Growth was also apparent in individual neurons and astrocytes in these 2 regions, and behavioral testing showed increased novelty approach in maze-trained rats in 2 different tests. Suppressing adult neurogenesis prevented the effects on structure and approach behavior after maze training without affecting maze learning itself. The vCA1 neurons projecting to the prelimbic area were more activated by novelty in maze-trained animals, and suppression of this pathway decreased approach behavior. Conclusions Rewarded navigational learning experiences induce volumetric and morphologic growth in the vCA1 and prelimbic cortex and enhance activation of the circuit connecting these 2 regions. Both the structural and behavioral effects of maze training require ongoing adult neurogenesis, suggesting a role for new neurons in experience-driven increases in novelty exploration.
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Affiliation(s)
- Timothy J. Schoenfeld
- Section on Neuroplasticity, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
- Department of Psychological Science and Neuroscience, Belmont University, Nashville, Tennessee
| | - Diane Rhee
- Section on Neuroplasticity, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Jesse A. Smith
- Section on Neuroplasticity, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Varun Padmanaban
- Section on Neuroplasticity, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Adam T. Brockett
- Department of Psychology and Princeton Neuroscience Institute, Princeton University, Princeton, New Jersey
| | - Hannah N. Jacobs
- Section on Neuroplasticity, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Heather A. Cameron
- Section on Neuroplasticity, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
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Gasalla P, Manahan-Vaughan D, Dwyer DM, Hall J, Méndez-Couz M. Characterisation of the neural basis underlying appetitive extinction & renewal in Cacna1c rats. Neuropharmacology 2023; 227:109444. [PMID: 36724867 DOI: 10.1016/j.neuropharm.2023.109444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 01/16/2023] [Accepted: 01/25/2023] [Indexed: 01/30/2023]
Abstract
Recent studies have revealed impairments in Cacna1c ± heterozygous animals (a gene that encodes the Cav 1.2 L-type voltage-gated calcium channels and is implicated in risk for multiple neuropsychiatric disorders) in aversive forms of learning, such as latent inhibition, reversal learning or context discrimination. However, the role of Cav 1.2 L-type voltage-gated calcium channels in extinction of appetitive associations remains under-investigated. Here, we used an appetitive Pavlovian conditioning task and evaluated extinction learning (EL) with a change of context from that of training and test (ABA) and without such a change (AAA) in Cacna1c ± male rats versus their wild-type (WT) littermates. In addition, we used fluorescence in situ hybridization of somatic immediate early genes (IEGs) Arc and Homer1a expression to scrutinize associated changes in the medial prefrontal cortex and the amygdala. Cacna1c ± animals successfully adapt their responses by engaging in appetitive EL and renewal. However, the regional IEG expression profile changed. For the EL occurring in the same context, Cacna1c ± animals presented higher IEG expression in the infralimbic cortex and the central amygdala than controls. The prelimbic region presented a larger neural ensemble in Cacna1c ± than WT animals, co-labelled for the time window of EL in the original context and prolonged exposure to the unrewarded context. With a context change, the Cacna1c ± infralimbic region displayed higher IEG expression during renewal than controls. Taken together, our findings provide novel evidence of distinct brain activation patterns occurring in Cacna1c ± rats after appetitive extinction and renewal despite preserved behavioral responses. This article is part of the Special Issue on "L-type calcium channel mechanisms in neuropsychiatric disorders".
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Affiliation(s)
- Patricia Gasalla
- Neuroscience & Mental Health Research Institute, School of Medicine, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ, UK; School of Psychology, Cardiff University, Tower Building, 70 Park Place, Cardiff, CF10 3AT, UK
| | - Denise Manahan-Vaughan
- Dept. Neurophysiology, Medical Faculty, Ruhr-University Bochum, Universitätsstraße 150, Building MA 4/158, 44780, Bochum, Germany
| | - Dominic Michael Dwyer
- School of Psychology, Cardiff University, Tower Building, 70 Park Place, Cardiff, CF10 3AT, UK
| | - Jeremy Hall
- Neuroscience & Mental Health Research Institute, School of Medicine, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ, UK
| | - Marta Méndez-Couz
- Dept. Neurophysiology, Medical Faculty, Ruhr-University Bochum, Universitätsstraße 150, Building MA 4/158, 44780, Bochum, Germany.
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Ferrara NC, Kwapis JL, Trask S. Memory retrieval, reconsolidation, and extinction: Exploring the boundary conditions of post-conditioning cue exposure. Front Synaptic Neurosci 2023; 15:1146665. [PMID: 36937567 PMCID: PMC10017482 DOI: 10.3389/fnsyn.2023.1146665] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 02/17/2023] [Indexed: 03/06/2023] Open
Abstract
Following fear conditioning, behavior can be reduced by giving many CS-alone presentations in a process known as extinction or by presenting a few CS-alone presentations and interfering with subsequent memory reconsolidation. While the two share procedural similarities, both the behavioral outcomes and the neurobiological underpinnings are distinct. Here we review the neural and behavioral mechanisms that produce these separate behavioral reductions, as well as some factors that determine whether or not a retrieval-dependent reconsolidation process or an extinction process will be in effect.
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Affiliation(s)
- Nicole C. Ferrara
- Discipline of Physiology and Biophysics, Rosalind Franklin University, North Chicago, IL, United States
- Center for Neurobiology of Stress Resilience and Psychiatric Disorders, Rosalind Franklin University, North Chicago, IL, United States
| | - Janine L. Kwapis
- Department of Biology, The Pennsylvania State University, University Park, PA, United States
| | - Sydney Trask
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, United States
- Purdue Institute for Integrative Neuroscience, West Lafayette, IN, United States
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Goral RO, Harper KM, Bernstein BJ, Fry SA, Lamb PW, Moy SS, Cushman JD, Yakel JL. Loss of GABA co-transmission from cholinergic neurons impairs behaviors related to hippocampal, striatal, and medial prefrontal cortex functions. Front Behav Neurosci 2022; 16:1067409. [PMID: 36505727 PMCID: PMC9730538 DOI: 10.3389/fnbeh.2022.1067409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 11/04/2022] [Indexed: 11/25/2022] Open
Abstract
Introduction: Altered signaling or function of acetylcholine (ACh) has been reported in various neurological diseases, including Alzheimer's disease, Tourette syndrome, epilepsy among others. Many neurons that release ACh also co-transmit the neurotransmitter gamma-aminobutyrate (GABA) at synapses in the hippocampus, striatum, substantia nigra, and medial prefrontal cortex (mPFC). Although ACh transmission is crucial for higher brain functions such as learning and memory, the role of co-transmitted GABA from ACh neurons in brain function remains unknown. Thus, the overarching goal of this study was to investigate how a systemic loss of GABA co-transmission from ACh neurons affected the behavioral performance of mice. Methods: To do this, we used a conditional knock-out mouse of the vesicular GABA transporter (vGAT) crossed with the ChAT-Cre driver line to selectively ablate GABA co-transmission at ACh synapses. In a comprehensive series of standardized behavioral assays, we compared Cre-negative control mice with Cre-positive vGAT knock-out mice of both sexes. Results: Loss of GABA co-transmission from ACh neurons did not disrupt the animal's sociability, motor skills or sensation. However, in the absence of GABA co-transmission, we found significant alterations in social, spatial and fear memory as well as a reduced reliance on striatum-dependent response strategies in a T-maze. In addition, male conditional knockout (CKO) mice showed increased locomotion. Discussion: Taken together, the loss of GABA co-transmission leads to deficits in higher brain functions and behaviors. Therefore, we propose that ACh/GABA co-transmission modulates neural circuitry involved in the affected behaviors.
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Affiliation(s)
- R. Oliver Goral
- Neurobiology Laboratory, Department of Health and Human Services, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, United States,Center on Compulsive Behaviors, National Institutes of Health, Bethesda, MD, United States
| | - Kathryn M. Harper
- Department of Psychiatry and Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, NC, United States
| | - Briana J. Bernstein
- Neurobiology Laboratory, Department of Health and Human Services, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, United States,Department of Health and Human Services, Neurobehavioral Core, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, United States
| | - Sydney A. Fry
- Neurobiology Laboratory, Department of Health and Human Services, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, United States,Department of Health and Human Services, Neurobehavioral Core, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, United States
| | - Patricia W. Lamb
- Neurobiology Laboratory, Department of Health and Human Services, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, United States
| | - Sheryl S. Moy
- Department of Psychiatry and Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, NC, United States
| | - Jesse D. Cushman
- Neurobiology Laboratory, Department of Health and Human Services, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, United States,Department of Health and Human Services, Neurobehavioral Core, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, United States
| | - Jerrel L. Yakel
- Neurobiology Laboratory, Department of Health and Human Services, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, United States,*Correspondence: Jerrel L. Yakel
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Oguchi M, Sakagami M. Dissecting the Prefrontal Network With Pathway-Selective Manipulation in the Macaque Brain—A Review. Front Neurosci 2022; 16:917407. [PMID: 35677354 PMCID: PMC9168219 DOI: 10.3389/fnins.2022.917407] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 05/05/2022] [Indexed: 11/13/2022] Open
Abstract
Macaque monkeys are prime animal models for studying the neural mechanisms of decision-making because of their close kinship with humans. Manipulation of neural activity during decision-making tasks is essential for approaching the causal relationship between the brain and its functions. Conventional manipulation methods used in macaque studies are coarse-grained, and have worked indiscriminately on mutually intertwined neural pathways. To systematically dissect neural circuits responsible for a variety of functions, it is essential to analyze changes in behavior and neural activity through interventions in specific neural pathways. In recent years, an increasing number of studies have applied optogenetics and chemogenetics to achieve fine-grained pathway-selective manipulation in the macaque brain. Here, we review the developments in macaque studies involving pathway-selective operations, with a particular focus on applications to the prefrontal network. Pathway selectivity can be achieved using single viral vector transduction combined with local light stimulation or ligand administration directly into the brain or double-viral vector transduction combined with systemic drug administration. We discuss the advantages and disadvantages of these methods. We also highlight recent technological developments in viral vectors that can effectively infect the macaque brain, as well as the development of methods to deliver photostimulation or ligand drugs to a wide area to effectively manipulate behavior. The development and dissemination of such pathway-selective manipulations of macaque prefrontal networks will enable us to efficiently dissect the neural mechanisms of decision-making and innovate novel treatments for decision-related psychiatric disorders.
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Raut SB, Marathe PA, van Eijk L, Eri R, Ravindran M, Benedek DM, Ursano RJ, Canales JJ, Johnson LR. Diverse therapeutic developments for post-traumatic stress disorder (PTSD) indicate common mechanisms of memory modulation. Pharmacol Ther 2022; 239:108195. [PMID: 35489438 DOI: 10.1016/j.pharmthera.2022.108195] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 04/19/2022] [Accepted: 04/20/2022] [Indexed: 12/20/2022]
Abstract
Post-traumatic stress disorder (PTSD), characterized by abnormally persistent and distressing memories, is a chronic debilitating condition in need of new treatment options. Current treatment guidelines recommend psychotherapy as first line management with only two drugs, sertraline and paroxetine, approved by U.S. Food and Drug Administration (FDA) for treatment of PTSD. These drugs have limited efficacy as they only reduce symptoms related to depression and anxiety without producing permanent remission. PTSD remains a significant public health problem with high morbidity and mortality requiring major advances in therapeutics. Early evidence has emerged for the beneficial effects of psychedelics particularly in combination with psychotherapy for management of PTSD, including psilocybin, MDMA, LSD, cannabinoids, ayahuasca and ketamine. MDMA and psilocybin reduce barrier to therapy by increasing trust between therapist and patient, thus allowing for modification of trauma related memories. Furthermore, research into the memory reconsolidation mechanisms has allowed for identification of various pharmacological targets to disrupt abnormally persistent memories. A number of pre-clinical and clinical studies have investigated novel and re-purposed pharmacological agents to disrupt fear memory in PTSD. Novel therapeutic approaches like neuropeptide Y, oxytocin, cannabinoids and neuroactive steroids have also shown potential for PTSD treatment. Here, we focus on the role of fear memory in the pathophysiology of PTSD and propose that many of these new therapeutic strategies produce benefits through the effect on fear memory. Evaluation of recent research findings suggests that while a number of drugs have shown promising results in preclinical studies and pilot clinical trials, the evidence from large scale clinical trials would be needed for these drugs to be incorporated in clinical practice.
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Affiliation(s)
- Sanket B Raut
- Schools of Psychological Sciences, College of Health and Medicine, University of Tasmania, TAS 7250, Australia
| | - Padmaja A Marathe
- Department of Pharmacology and Therapeutics, Seth GS Medical College & KEM Hospital, Parel, Mumbai 400 012, India
| | - Liza van Eijk
- Department of Psychology, College of Healthcare Sciences, James Cook University, QLD 4811, Australia
| | - Rajaraman Eri
- Health Sciences, College of Health and Medicine, University of Tasmania, TAS 7250, Australia
| | - Manoj Ravindran
- Medicine, College of Health and Medicine, University of Tasmania, TAS 7250, Australia; Department of Psychiatry, North-West Private Hospital, Burnie TAS 7320, Australia
| | - David M Benedek
- Centre for the Study of Traumatic Stress, Department of Psychiatry, Uniformed Services University School of Medicine, Bethesda, MD 20814, USA
| | - Robert J Ursano
- Centre for the Study of Traumatic Stress, Department of Psychiatry, Uniformed Services University School of Medicine, Bethesda, MD 20814, USA
| | - Juan J Canales
- Schools of Psychological Sciences, College of Health and Medicine, University of Tasmania, TAS 7250, Australia
| | - Luke R Johnson
- Schools of Psychological Sciences, College of Health and Medicine, University of Tasmania, TAS 7250, Australia; Centre for the Study of Traumatic Stress, Department of Psychiatry, Uniformed Services University School of Medicine, Bethesda, MD 20814, USA.
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Namkung H, Thomas KL, Hall J, Sawa A. Parsing neural circuits of fear learning and extinction across basic and clinical neuroscience: Towards better translation. Neurosci Biobehav Rev 2022; 134:104502. [PMID: 34921863 DOI: 10.1016/j.neubiorev.2021.12.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 12/13/2021] [Accepted: 12/14/2021] [Indexed: 12/22/2022]
Abstract
Over the past decades, studies of fear learning and extinction have advanced our understanding of the neurobiology of threat and safety learning. Animal studies can provide mechanistic/causal insights into human brain regions and their functional connectivity involved in fear learning and extinction. Findings in humans, conversely, may further enrich our understanding of neural circuits in animals by providing macroscopic insights at the level of brain-wide networks. Nevertheless, there is still much room for improvement in translation between basic and clinical research on fear learning and extinction. Through the lens of neural circuits, in this article, we aim to review the current knowledge of fear learning and extinction in both animals and humans, and to propose strategies to fill in the current knowledge gap for the purpose of enhancing clinical benefits.
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Affiliation(s)
- Ho Namkung
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA; Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Kerrie L Thomas
- Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff, UK; School of Biosciences, Cardiff University, Cardiff, UK
| | - Jeremy Hall
- Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff, UK; School of Medicine, Cardiff University, Cardiff, UK
| | - Akira Sawa
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA; Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA; Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA; Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA; Department of Mental Health, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, 21287, USA.
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Szadzinska W, Danielewski K, Kondrakiewicz K, Andraka K, Nikolaev E, Mikosz M, Knapska E. Hippocampal Inputs in the Prelimbic Cortex Curb Fear after Extinction. J Neurosci 2021; 41:9129-9140. [PMID: 34518304 PMCID: PMC8570826 DOI: 10.1523/jneurosci.0764-20.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 07/23/2021] [Accepted: 07/29/2021] [Indexed: 11/21/2022] Open
Abstract
In contrast to easily formed fear memories, fear extinction requires prolonged training. The prelimbic cortex (PL), which integrates signals from brain structures involved in fear conditioning and extinction such as the ventral hippocampus (vHIP) and the basolateral amygdala (BL), is necessary for fear memory retrieval. Little is known, however, about how the vHIP and BL inputs to the PL regulate the display of fear after fear extinction. Using functional anatomy tracing in male rats, we found two distinct subpopulations of neurons in the PL activated by either the successful extinction or the relapse of fear. During the retrieval of fear extinction memory, the dominant input to active neurons in the PL was from the vHIP, whereas the retrieval of fear memory, regardless of the age of a memory and testing context, was associated with greater BL input. Optogenetic stimulation of the vHIP-PL pathway after one session of fear extinction increased conditioned fear, whereas stimulation of the vHIP inputs after several sessions of extinction decreased the conditioned fear response. This latter effect was, however, transient, as stimulation of this pathway 28 d after extinction increased conditioned fear response again. The results show that repeated fear extinction training gradually changes vHIP-PL connectivity, making fear suppression possible, whereas in the absence of fear suppression from the vHIP, signals from the BL can play a dominant role, resulting in high levels of fear.SIGNIFICANCE STATEMENT Behavioral therapies of fear are based on extinction learning. As extinction memories fade over time, such therapies produce only a temporary suppression of fear, which constitutes a clinical and societal challenge. In our study, we provide a framework for understating the underlying mechanism by which extinction of fear memories fade by demonstrating the existence of two subpopulations of neurons in the prelimbic cortex associated with low and high levels of fear. Insufficient extinction and exposure to the context in which fear memory was formed promoted high fear neuronal activity in the prelimbic cortex, leading to fear retrieval. Extensive extinction training, on the other hand, boosted low fear neuronal activity and, as a result, extinction memory retrieval. This effect was, however, transient and disappeared with time.
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Affiliation(s)
- Weronika Szadzinska
- Laboratory of Emotions Neurobiology, Nencki-European Molecular Biology Laboratory Partnership for Neural Plasticity and Brain Disorders BRAINCITY, Nencki Institute of Experimental Biology, Pasteur 3 Str., 02-093 Warsaw, Poland
| | - Konrad Danielewski
- Laboratory of Emotions Neurobiology, Nencki-European Molecular Biology Laboratory Partnership for Neural Plasticity and Brain Disorders BRAINCITY, Nencki Institute of Experimental Biology, Pasteur 3 Str., 02-093 Warsaw, Poland
| | - Kacper Kondrakiewicz
- Laboratory of Emotions Neurobiology, Nencki-European Molecular Biology Laboratory Partnership for Neural Plasticity and Brain Disorders BRAINCITY, Nencki Institute of Experimental Biology, Pasteur 3 Str., 02-093 Warsaw, Poland
| | - Karolina Andraka
- Laboratory of Emotions Neurobiology, Nencki-European Molecular Biology Laboratory Partnership for Neural Plasticity and Brain Disorders BRAINCITY, Nencki Institute of Experimental Biology, Pasteur 3 Str., 02-093 Warsaw, Poland
| | - Evgeni Nikolaev
- Laboratory of Emotions Neurobiology, Nencki-European Molecular Biology Laboratory Partnership for Neural Plasticity and Brain Disorders BRAINCITY, Nencki Institute of Experimental Biology, Pasteur 3 Str., 02-093 Warsaw, Poland
| | - Marta Mikosz
- Laboratory of Emotions Neurobiology, Nencki-European Molecular Biology Laboratory Partnership for Neural Plasticity and Brain Disorders BRAINCITY, Nencki Institute of Experimental Biology, Pasteur 3 Str., 02-093 Warsaw, Poland
| | - Ewelina Knapska
- Laboratory of Emotions Neurobiology, Nencki-European Molecular Biology Laboratory Partnership for Neural Plasticity and Brain Disorders BRAINCITY, Nencki Institute of Experimental Biology, Pasteur 3 Str., 02-093 Warsaw, Poland
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11
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Oguchi M, Tanaka S, Pan X, Kikusui T, Moriya-Ito K, Kato S, Kobayashi K, Sakagami M. Chemogenetic inactivation reveals the inhibitory control function of the prefronto-striatal pathway in the macaque brain. Commun Biol 2021; 4:1088. [PMID: 34531520 PMCID: PMC8446038 DOI: 10.1038/s42003-021-02623-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 09/01/2021] [Indexed: 02/08/2023] Open
Abstract
The lateral prefrontal cortex (LPFC) has a strong monosynaptic connection with the caudate nucleus (CdN) of the striatum. Previous human MRI studies have suggested that this LPFC-CdN pathway plays an important role in inhibitory control and working memory. We aimed to validate the function of this pathway at a causal level by pathway-selective manipulation of neural activity in non-human primates. To this end, we trained macaque monkeys on a delayed oculomotor response task with reward asymmetry and expressed an inhibitory type of chemogenetic receptors selectively to LPFC neurons that project to the CdN. Ligand administration reduced the inhibitory control of impulsive behavior, as well as the task-related neuronal responses observed in the local field potentials from the LPFC and CdN. These results show that we successfully suppressed pathway-selective neural activity in the macaque brain, and the resulting behavioral changes suggest that the LPFC-CdN pathway is involved in inhibitory control.
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Affiliation(s)
- Mineki Oguchi
- grid.412905.b0000 0000 9745 9416Brain Science Institute, Tamagawa University, Tokyo, Japan ,grid.252643.40000 0001 0029 6233School of Veterinary Medicine, Azabu University, Kanagawa, Japan
| | - Shingo Tanaka
- grid.412905.b0000 0000 9745 9416Brain Science Institute, Tamagawa University, Tokyo, Japan ,grid.260975.f0000 0001 0671 5144Department of Physiology, School of Medicine, Niigata University, Niigata, Japan
| | - Xiaochuan Pan
- grid.28056.390000 0001 2163 4895Institute for Cognitive Neurodynamics, East China University of Science and Technology, Shanghai, China
| | - Takefumi Kikusui
- grid.252643.40000 0001 0029 6233School of Veterinary Medicine, Azabu University, Kanagawa, Japan
| | - Keiko Moriya-Ito
- grid.272456.0Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Shigeki Kato
- grid.411582.b0000 0001 1017 9540Department of Molecular Genetics, Institute of Biomedical Sciences, Fukushima Medical University, Fukushima, Japan
| | - Kazuto Kobayashi
- grid.411582.b0000 0001 1017 9540Department of Molecular Genetics, Institute of Biomedical Sciences, Fukushima Medical University, Fukushima, Japan
| | - Masamichi Sakagami
- grid.412905.b0000 0000 9745 9416Brain Science Institute, Tamagawa University, Tokyo, Japan
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12
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Méndez-Couz M, Krenzek B, Manahan-Vaughan D. Genetic Depletion of BDNF Impairs Extinction Learning of a Spatial Appetitive Task in the Presence or Absence of the Acquisition Context. Front Behav Neurosci 2021; 15:658686. [PMID: 33994970 PMCID: PMC8119774 DOI: 10.3389/fnbeh.2021.658686] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/26/2021] [Indexed: 12/12/2022] Open
Abstract
Brain derived neurotropic factor (BDNF) supports neuronal survival, growth, and differentiation and is involved in forms of hippocampus-dependent and independent learning, as well as hippocampus-dependent learning. Extinction learning comprises active inhibition of no-longer relevant learned information, in conjunction with a decreased response of a previously learned behavior. It is highly dependent on context, and evidence exists that it requires hippocampal activation. The participation of BDNF in memory processing is experience-dependent. For example, BDNF has been associated with synaptic plasticity needed for spatial learning, and it is involved in acquisition and extinction learning of fear conditioning. However, little is known about its role in spatial appetitive extinction learning. In this study, we evaluated to what extent BDNF contributes to spatial appetitive extinction learning in the presence (ABA) or absence (AAA) of exposure to the acquisition context. Daily training, of BDNF+/--mice or their wildtype (WT) littermates, to reach acquisition criterion in a T-maze, resulted in a similar performance outcome. However, extinction learning was delayed in the AAA, and impaired in the ABA-paradigm compared to performance in WT littermates. Trial-by-trial learning analysis indicated differences in the integration of the context into extinction learning by BDNF+/--mice compared to WT littermates. Taken together, these results support an important role for BDNF in processes that relate to information updating and retrieval that in turn are crucial for effective extinction learning.
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Affiliation(s)
- Marta Méndez-Couz
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum, Germany
| | - Beate Krenzek
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum, Germany
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13
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Bouton ME, Maren S, McNally GP. BEHAVIORAL AND NEUROBIOLOGICAL MECHANISMS OF PAVLOVIAN AND INSTRUMENTAL EXTINCTION LEARNING. Physiol Rev 2021; 101:611-681. [PMID: 32970967 PMCID: PMC8428921 DOI: 10.1152/physrev.00016.2020] [Citation(s) in RCA: 146] [Impact Index Per Article: 48.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
This article reviews the behavioral neuroscience of extinction, the phenomenon in which a behavior that has been acquired through Pavlovian or instrumental (operant) learning decreases in strength when the outcome that reinforced it is removed. Behavioral research indicates that neither Pavlovian nor operant extinction depends substantially on erasure of the original learning but instead depends on new inhibitory learning that is primarily expressed in the context in which it is learned, as exemplified by the renewal effect. Although the nature of the inhibition may differ in Pavlovian and operant extinction, in either case the decline in responding may depend on both generalization decrement and the correction of prediction error. At the neural level, Pavlovian extinction requires a tripartite neural circuit involving the amygdala, prefrontal cortex, and hippocampus. Synaptic plasticity in the amygdala is essential for extinction learning, and prefrontal cortical inhibition of amygdala neurons encoding fear memories is involved in extinction retrieval. Hippocampal-prefrontal circuits mediate fear relapse phenomena, including renewal. Instrumental extinction involves distinct ensembles in corticostriatal, striatopallidal, and striatohypothalamic circuits as well as their thalamic returns for inhibitory (extinction) and excitatory (renewal and other relapse phenomena) control over operant responding. The field has made significant progress in recent decades, although a fully integrated biobehavioral understanding still awaits.
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Affiliation(s)
- Mark E Bouton
- Department of Psychological Science, University of Vermont, Burlington, Vermont
| | - Stephen Maren
- Department of Psychological and Brain Sciences and Institute for Neuroscience, Texas A&M University, College Station, Texas
| | - Gavan P McNally
- School of Psychology, University of New South Wales, Sydney, Australia
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14
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Understanding the dynamic and destiny of memories. Neurosci Biobehav Rev 2021; 125:592-607. [PMID: 33722616 DOI: 10.1016/j.neubiorev.2021.03.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 01/18/2021] [Accepted: 03/08/2021] [Indexed: 01/16/2023]
Abstract
Memory formation enables the retention of life experiences overtime. Based on previously acquired information, organisms can anticipate future events and adjust their behaviors to maximize survival. However, in an ever-changing environment, a memory needs to be malleable to maintain its relevance. In fact, substantial evidence suggests that a consolidated memory can become labile and susceptible to modifications after being reactivated, a process termed reconsolidation. When an extinction process takes place, a memory can also be temporarily inhibited by a second memory that carries information with opposite meaning. In addition, a memory can fade and lose its significance in a process known as forgetting. Thus, following retrieval, new life experiences can be integrated with the original memory trace to maintain its predictive value. In this review, we explore the determining factors that regulate the fate of a memory after its reactivation. We focus on three post-retrieval memory destinies (reconsolidation, extinction, and forgetting) and discuss recent rodent studies investigating the biological functions and neural mechanisms underlying each of these processes.
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15
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Goldberg LR, Zeid D, Kutlu MG, Cole RD, Lallai V, Sebastian A, Albert I, Fowler CD, Parikh V, Gould TJ. Paternal nicotine enhances fear memory, reduces nicotine administration, and alters hippocampal genetic and neural function in offspring. Addict Biol 2021; 26:e12859. [PMID: 31782218 DOI: 10.1111/adb.12859] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 10/07/2019] [Accepted: 11/07/2019] [Indexed: 12/22/2022]
Abstract
Nicotine use remains highly prevalent with tobacco and e-cigarette products consumed worldwide. However, increasing evidence of transgenerational epigenetic inheritance suggests that nicotine use may alter behavior and neurobiology in subsequent generations. We tested the effects of chronic paternal nicotine exposure in C57BL6/J mice on fear conditioning in F1 and F2 offspring, as well as conditioned fear extinction and spontaneous recovery, nicotine self-administration, hippocampal cholinergic functioning, RNA expression, and DNA methylation in F1 offspring. Paternal nicotine exposure was associated with enhanced contextual and cued fear conditioning and spontaneous recovery of extinguished fear memories. Further, nicotine reinforcement was reduced in nicotine-sired mice, as assessed in a self-administration paradigm. These behavioral phenotypes were coupled with altered response to nicotine, upregulated hippocampal nicotinic acetylcholine receptor binding, reduced evoked hippocampal cholinergic currents, and altered methylation and expression of hippocampal genes related to neural development and plasticity. Gene expression analysis suggests multigenerational effects on broader gene networks potentially involved in neuroplasticity and mental disorders. The changes in fear conditioning similarly suggest phenotypes analogous to anxiety disorders similar to post-traumatic stress.
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Affiliation(s)
- Lisa R. Goldberg
- Department of Biobehavioral Health Penn State University University Park Pennsylvania
| | - Dana Zeid
- Department of Biobehavioral Health Penn State University University Park Pennsylvania
| | - Munir Gunes Kutlu
- Department of Pharmacology Vanderbilt School of Medicine Nashville Tennessee
| | - Robert D. Cole
- College of Pharmacy University of Kentucky Lexington Kentucky
| | - Valeria Lallai
- Department of Neurobiology and Behavior University of California Irvine Irvine California
| | - Aswathy Sebastian
- Bioinformatics, Biochemistry and Molecular Biology Penn State University University Park PA
| | - Istvan Albert
- Bioinformatics, Biochemistry and Molecular Biology Penn State University University Park PA
| | - Christie D. Fowler
- Department of Neurobiology and Behavior University of California Irvine Irvine California
| | - Vinay Parikh
- Department of Psychology Temple University Philadelphia Pennsylvania
| | - Thomas J. Gould
- Department of Biobehavioral Health Penn State University University Park Pennsylvania
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16
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Bryant KG, Barker JM. Arbitration of Approach-Avoidance Conflict by Ventral Hippocampus. Front Neurosci 2020; 14:615337. [PMID: 33390895 PMCID: PMC7773818 DOI: 10.3389/fnins.2020.615337] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 11/27/2020] [Indexed: 11/24/2022] Open
Abstract
When environmental cues or stimuli that represent both rewarding and aversive outcomes are presented, complex computations must be made in order to determine whether approach or avoidance is the better behavioral strategy. In many neuropsychiatric illnesses these computations can be skewed. In some instances, circumstances that may normally warrant avoidance instead promote approach, thus producing compulsive-like behavioral strategies that are inflexible in response to new or conflicting information. Alternatively, high sensitivity to aversion or low sensitivity to reward can result in the failure to achieve goals and loss of resilience that characterizes depressive disorders. Increases in compulsive-like behavior have been found to be associated with disrupted signaling in regions that regulate response to conflicting stimuli, including the hippocampus. Classic behavioral inhibition theories of hippocampus function in anxiety suggest that the hippocampus blocks aberrant behavior in response to anxiety related cues or stimuli. The hippocampus may act to block approach in the face of conflicting stimuli. Dysregulations of hippocampal function, as may be present in neuropsychiatric disorders, may therefore promote aberrant approach behavior. The ventral hippocampus (vHPC) subregion is key for coordinating this approach/avoidance conflict resolution, likely through its participation with cortico-striatal and mesolimbic circuits. We revisit Gray's behavioral inhibition theory of HPC function, first posited in the 1980s, and interpret in the context of new knowledge on vHPC function gained through modern technology. Taken together with the extant, classical literature on hippocampal function, we propose that these new findings suggest that vHPC circuits balance behavioral response to conflicting stimuli in a manner that is both state- and context-dependent and, further, that disruption of specific vHPC circuits tips the balance in favor of biased approach or avoidance behavioral strategies.
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Affiliation(s)
- Kathleen G Bryant
- Department of Pharmacology and Physiology, Drexel University, Philadelphia, PA, United States
| | - Jacqueline M Barker
- Department of Pharmacology and Physiology, Drexel University, Philadelphia, PA, United States
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17
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Notaras M, van den Buuse M. Neurobiology of BDNF in fear memory, sensitivity to stress, and stress-related disorders. Mol Psychiatry 2020; 25:2251-2274. [PMID: 31900428 DOI: 10.1038/s41380-019-0639-2] [Citation(s) in RCA: 183] [Impact Index Per Article: 45.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 12/01/2019] [Accepted: 12/12/2019] [Indexed: 01/17/2023]
Abstract
Brain-derived neurotrophic factor (BDNF) is widely accepted for its involvement in resilience and antidepressant drug action, is a common genetic locus of risk for mental illnesses, and remains one of the most prominently studied molecules within psychiatry. Stress, which arguably remains the "lowest common denominator" risk factor for several mental illnesses, targets BDNF in disease-implicated brain regions and circuits. Altered stress-related responses have also been observed in animal models of BDNF deficiency in vivo, and BDNF is a common downstream intermediary for environmental factors that potentiate anxiety- and depressive-like behavior. However, BDNF's broad functionality has manifested a heterogeneous literature; likely reflecting that BDNF plays a hitherto under-recognized multifactorial role as both a regulator and target of stress hormone signaling within the brain. The role of BDNF in vulnerability to stress and stress-related disorders, such as posttraumatic stress disorder (PTSD), is a prominent example where inconsistent effects have emerged across numerous models, labs, and disciplines. In the current review we provide a contemporary update on the neurobiology of BDNF including new data from the behavioral neuroscience and neuropsychiatry literature on fear memory consolidation and extinction, stress, and PTSD. First we present an overview of recent advances in knowledge on the role of BDNF within the fear circuitry, as well as address mounting evidence whereby stress hormones interact with endogenous BDNF-TrkB signaling to alter brain homeostasis. Glucocorticoid signaling also acutely recruits BDNF to enhance the expression of fear memory. We then include observations that the functional common BDNF Val66Met polymorphism modulates stress susceptibility as well as stress-related and stress-inducible neuropsychiatric endophenotypes in both man and mouse. We conclude by proposing a BDNF stress-sensitivity hypothesis, which posits that disruption of endogenous BDNF activity by common factors (such as the BDNF Val66Met variant) potentiates sensitivity to stress and, by extension, vulnerability to stress-inducible illnesses. Thus, BDNF may induce plasticity to deleteriously promote the encoding of fear and trauma but, conversely, also enable adaptive plasticity during extinction learning to suppress PTSD-like fear responses. Ergo regulators of BDNF availability, such as the Val66Met polymorphism, may orchestrate sensitivity to stress, trauma, and risk of stress-induced disorders such as PTSD. Given an increasing interest in personalized psychiatry and clinically complex cases, this model provides a framework from which to experimentally disentangle the causal actions of BDNF in stress responses, which likely interact to potentiate, produce, and impair treatment of, stress-related psychiatric disorders.
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Affiliation(s)
- Michael Notaras
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, Cornell University, New York, NY, USA.
| | - Maarten van den Buuse
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC, Australia. .,College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia. .,Department of Pharmacology, University of Melbourne, Melbourne, VIC, Australia.
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18
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Hallock HL, Quillian HM, Maynard KR, Mai Y, Chen HY, Hamersky GR, Shin JH, Maher BJ, Jaffe AE, Martinowich K. Molecularly Defined Hippocampal Inputs Regulate Population Dynamics in the Prelimbic Cortex to Suppress Context Fear Memory Retrieval. Biol Psychiatry 2020; 88:554-565. [PMID: 32560963 PMCID: PMC7487039 DOI: 10.1016/j.biopsych.2020.04.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 04/13/2020] [Accepted: 04/15/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Context fear memory dysregulation is a hallmark symptom of several neuropsychiatric disorders, including generalized anxiety disorder and posttraumatic stress disorder. The hippocampus (HC) and prelimbic (PrL) subregion of the medial prefrontal cortex have been linked with context fear memory retrieval in rodents, but the mechanisms by which HC-PrL circuitry regulates this process remain poorly understood. METHODS Spatial and genetic targeting of HC-PrL circuitry was used for RNA sequencing (n = 31), chemogenetic stimulation (n = 44), in vivo calcium imaging (n = 20), ex vivo electrophysiology (n = 8), and molecular regulation of plasticity cascades during fear behavior (context fear retrieval) (n = 16). RESULTS We showed that ventral HC (vHC) neurons with projections to the PrL cortex (vHC-PrL projectors) are a transcriptomically distinct subpopulation compared with adjacent nonprojecting neurons, and we showed complementary enrichment for diverse neuronal processes and central nervous system-related clinical gene sets. We further showed that stimulation of this population of vHC-PrL projectors suppresses context fear memory retrieval and impairs the ability of PrL neurons to dynamically distinguish between distinct phases of fear learning. Using transgenic and circuit-specific molecular targeting approaches, we demonstrated that unique patterns of activity-dependent gene transcription associated with brain-derived neurotrophic factor signaling within vHC-PrL projectors causally regulated activity in excitatory and inhibitory PrL neurons during context fear memory retrieval. CONCLUSIONS Together, our data show that activity-dependent brain-derived neurotrophic factor release from molecularly distinct vHC-PrL projection neurons modulates postsynaptic signaling in both inhibitory and excitatory PrL neurons, modifying activity in discrete populations of PrL neurons to suppress freezing during context fear memory retrieval.
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Affiliation(s)
| | | | | | - Yishan Mai
- The Lieber Institute for Brain Development, Baltimore, MD
| | - Huei-Ying Chen
- The Lieber Institute for Brain Development, Baltimore, MD
| | | | - Joo Heon Shin
- The Lieber Institute for Brain Development, Baltimore, MD
| | - Brady J. Maher
- The Lieber Institute for Brain Development, Baltimore, MD,Department of Psychiatry, The Johns Hopkins University School of Medicine, Baltimore, MD,Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD
| | - Andrew E. Jaffe
- The Lieber Institute for Brain Development, Baltimore, MD,Department of Psychiatry, The Johns Hopkins University School of Medicine, Baltimore, MD,Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD,Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD,Center for Computational Biology, Johns Hopkins University, Baltimore, MD,McKusick-Nathans Institute for Genetic Medicine, Johns Hopkins School of Medicine, Baltimore, MD
| | - Keri Martinowich
- Lieber Institute for Brain Development, Baltimore, Maryland; Department of Psychiatry, The Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
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19
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Wood RI, Serpa RO. Anabolic-androgenic steroid abuse and cognitive impairment: Testosterone IMPAIRS biconditional task performance in male rats. Behav Brain Res 2019; 379:112339. [PMID: 31697985 DOI: 10.1016/j.bbr.2019.112339] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 10/30/2019] [Accepted: 10/31/2019] [Indexed: 01/01/2023]
Abstract
Our goal is to understand the consequences of anabolic-androgenic steroid (AAS) abuse on cognitive function, using rats as a model. There is relatively little research on how AAS abuse impacts cognition. In the present study, rats were tested for their ability to use contextual information to guide decision-making in biconditional discrimination. The Stroop task is a classic human test for contextual decision-making. In rodents, biconditional discrimination challenges subjects to use contextual cues in the operant chamber to resolve the correct lever response when auditory and visual cues are incongruent. The hypothesis is that chronic high-dose testosterone impairs biconditional discrimination. Rats were trained in 24 trials/day over 14 days, in alternating sessions with each environment. On a flat floor with houselight illuminated, auditory cues (clicker vs tone) signified the active lever. On a barred floor with no light, visual cues from 2 stimulus lights (constant vs blinking) identified the active lever. Rats treated chronically with testosterone (7.5 mg/kg) were unimpaired in task acquisition, and all rats learned to select the correct lever in response to auditory or visual cues. During extinction, controls made significantly more correct than incorrect responses in congruent trials (p < 0.05 by paired t-test), but testosterone-treated rats failed to show a similar preference. This was reflected by significant interactions of drug x cue agreement (F1,18 = 5.21, p < 0.05) and drug x cue agreement x response accuracy (F1,18 = 8.95, p < 0.05). These results suggest that testosterone impairs cognitive flexibility, and demonstrates potential for AAS abuse to impair cognitive function in humans.
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Affiliation(s)
- Ruth I Wood
- Department of Integrative Anatomical Sciences, Keck School of Medicine at the University of Southern California, Los Angeles, CA, 90033, United States.
| | - Rebecka O Serpa
- Department of Integrative Anatomical Sciences, Keck School of Medicine at the University of Southern California, Los Angeles, CA, 90033, United States
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