1
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Salehabadi S, Abrari K, Elahdadi Salmani M, Nasiri M, Lashkarbolouki T. Investigating the role of the amygdala orexin receptor 1 in memory acquisition and extinction in a rat model of PTSD. Behav Brain Res 2020; 384:112455. [DOI: 10.1016/j.bbr.2019.112455] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 12/17/2019] [Accepted: 12/26/2019] [Indexed: 11/15/2022]
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2
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Amygdalar corticotropin-releasing factor mediates stress-induced anxiety. Brain Res 2019; 1729:146622. [PMID: 31881185 DOI: 10.1016/j.brainres.2019.146622] [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: 06/05/2019] [Revised: 11/07/2019] [Accepted: 12/23/2019] [Indexed: 12/19/2022]
Abstract
The extended amygdala, including the Central nucleus of the Amygdala (CeA) and the Bed Nucleus of the Stria Terminalis (BNST), is a complex structure that plays a pivotal role in emotional behavior. The CeA and the BNST are highly interconnected, being the amygdala traditionally more associated with fear and the BNST with anxiety. Yet, studies using excitotoxic lesions also show the involvement of the CeA in the development of stress-induced anxiety. Likewise, others have also highlighted the role of corticotropin-releasing factor (CRF), a neuropeptide highly expressed in CeA, as an anxiogenic factor and, consequently, important for in anxiety disorders. Here, we used an inducible RNAi lentiviral system to assess the effects of reducing CRF expression in CeA in the development of anxiety-like behavior in a model of Chronic Unpredictable Stress. In addition, we evaluated CRF RNAi-mediated alterations in the stress-triggered molecular signature in the BNST. Knockdown of CRF in the CeA decreased stress-induced anxiety levels. No differences were found in a fear-potentiated startle paradigm. Additionally, we observed that stress-induced alterations in the expression of CRF receptors within the BNST are attenuated by CRF knockdown in the CeA. These results emphasize the importance of the role that amygdalar CRF plays in the modulation of anxiety-like behavior and in the molecular signature of stress in the BNST.
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3
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Maddox SA, Hartmann J, Ross RA, Ressler KJ. Deconstructing the Gestalt: Mechanisms of Fear, Threat, and Trauma Memory Encoding. Neuron 2019; 102:60-74. [PMID: 30946827 DOI: 10.1016/j.neuron.2019.03.017] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 03/03/2019] [Accepted: 03/12/2019] [Indexed: 01/14/2023]
Abstract
Threat processing is central to understanding debilitating fear- and trauma-related disorders such as posttraumatic stress disorder (PTSD). Progress has been made in understanding the neural circuits underlying the "engram" of threat or fear memory formation that complements a decades-old appreciation of the neurobiology of fear and threat involving hub structures such as the amygdala. In this review, we examine key recent findings, as well as integrate the importance of hormonal and physiological approaches, to provide a broader perspective of how bodily systems engaged in threat responses may interact with amygdala-based circuits in the encoding and updating of threat-related memory. Understanding how trauma-related memories are encoded and updated throughout the brain and the body will ultimately lead to novel biologically-driven approaches for treatment and prevention.
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Affiliation(s)
- Stephanie A Maddox
- Neurobiology of Fear Laboratory, Division of Depression and Anxiety Disorders, McLean Hospital, 115 Mill Street, Belmont, MA 02478, USA; Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA
| | - Jakob Hartmann
- Neurobiology of Fear Laboratory, Division of Depression and Anxiety Disorders, McLean Hospital, 115 Mill Street, Belmont, MA 02478, USA; Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA
| | - Rachel A Ross
- Neurobiology of Fear Laboratory, Division of Depression and Anxiety Disorders, McLean Hospital, 115 Mill Street, Belmont, MA 02478, USA; Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA
| | - Kerry J Ressler
- Neurobiology of Fear Laboratory, Division of Depression and Anxiety Disorders, McLean Hospital, 115 Mill Street, Belmont, MA 02478, USA; Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA.
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4
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Dedic N, Kühne C, Gomes KS, Hartmann J, Ressler KJ, Schmidt MV, Deussing JM. Deletion of CRH From GABAergic Forebrain Neurons Promotes Stress Resilience and Dampens Stress-Induced Changes in Neuronal Activity. Front Neurosci 2019; 13:986. [PMID: 31619956 PMCID: PMC6763571 DOI: 10.3389/fnins.2019.00986] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 09/02/2019] [Indexed: 12/15/2022] Open
Abstract
Dysregulation of the corticotropin-releasing hormone (CRH) system has been implicated in stress-related psychopathologies such as depression and anxiety. Although most studies have linked CRH/CRH receptor 1 signaling to aversive, stress-like behavior, recent work has revealed a crucial role for distinct CRH circuits in maintaining positive emotional valence and appetitive responses under baseline conditions. Here we addressed whether deletion of CRH, specifically from GABAergic forebrain neurons (Crh CKO-GABA mice) differentially affects general behavior under baseline and chronic stress conditions. Expression mapping in Crh CK O-GABA mice revealed absence of Crh in GABAergic neurons of the cortex and limbic regions including the hippocampus, central nucleus of the amygdala and the bed nucleus of the stria terminals, but not in the paraventricular nucleus of hypothalamus. Consequently, conditional CRH knockout animals exhibited no alterations in circadian and stress-induced corticosterone release compared to controls. Under baseline conditions, absence of Crh from forebrain GABAergic neurons resulted in social interaction deficits but had no effect on other behavioral measures including locomotion, anxiety, immobility in the forced swim test, acoustic startle response and fear conditioning. Interestingly, following exposure to chronic social defeat stress, Crh CKO-GABA mice displayed a resilient phenotype, which was accompanied by a dampened, stress-induced expression of immediate early genes c-fos and zif268 in several brain regions. Collectively our data reveals the requirement of GABAergic CRH circuits in maintaining appropriate social behavior in naïve animals and further supports the ability of CRH to promote divergent behavioral states under baseline and severe stress conditions.
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Affiliation(s)
- Nina Dedic
- Molecular Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany.,Department of Psychiatry, Harvard Medical School and McLean Hospital, Belmont, MA, United States
| | - Claudia Kühne
- Molecular Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Karina S Gomes
- Molecular Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany.,Laboratory of Neuropsychopharmacology, Paulista State University, Araraquara, Brazil
| | - Jakob Hartmann
- Department of Psychiatry, Harvard Medical School and McLean Hospital, Belmont, MA, United States.,Stress Resilience, Max Planck Institute of Psychiatry, Munich, Germany
| | - Kerry J Ressler
- Department of Psychiatry, Harvard Medical School and McLean Hospital, Belmont, MA, United States
| | - Mathias V Schmidt
- Stress Resilience, Max Planck Institute of Psychiatry, Munich, Germany
| | - Jan M Deussing
- Molecular Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
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5
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Velasco ER, Florido A, Milad MR, Andero R. Sex differences in fear extinction. Neurosci Biobehav Rev 2019; 103:81-108. [PMID: 31129235 PMCID: PMC6692252 DOI: 10.1016/j.neubiorev.2019.05.020] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 03/08/2019] [Accepted: 05/19/2019] [Indexed: 12/18/2022]
Abstract
Despite the exponential increase in fear research during the last years, few studies have included female subjects in their design. The need to include females arises from the knowledge gap of mechanistic processes underlying the behavioral and neural differences observed in fear extinction. Moreover, the exact contribution of sex and hormones in relation to learning and behavior is still largely unknown. Insights from this field could be beneficial as fear-related disorders are twice as prevalent in women compared to men. Here, we review an up-to-date summary of animal and human studies in adulthood that report sex differences in fear extinction from a structural and functional approach. Furthermore, we describe how these factors could contribute to the observed sex differences in fear extinction during normal and pathological conditions.
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Affiliation(s)
- E R Velasco
- Institut de Neurociències, Universitat Autònoma de Barcelona, Spain
| | - A Florido
- Institut de Neurociències, Universitat Autònoma de Barcelona, Spain
| | - M R Milad
- Department of Psychiatry, University of Illinois at Chicago, USA
| | - R Andero
- Institut de Neurociències, Universitat Autònoma de Barcelona, Spain; CIBERSAM, Corporació Sanitaria Parc Taulí, Sabadell, Spain; Department of Psychobiology and Methodology of Health Sciences, Universitat Autònoma de Barcelona, Spain.
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6
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Diehl MM, Bravo-Rivera C, Rodriguez-Romaguera J, Pagan-Rivera PA, Burgos-Robles A, Roman-Ortiz C, Quirk GJ. Active avoidance requires inhibitory signaling in the rodent prelimbic prefrontal cortex. eLife 2018; 7:34657. [PMID: 29851381 PMCID: PMC5980229 DOI: 10.7554/elife.34657] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 05/06/2018] [Indexed: 12/27/2022] Open
Abstract
Much is known about the neural circuits of conditioned fear and its relevance to understanding anxiety disorders, but less is known about other anxiety-related behaviors such as active avoidance. Using a tone-signaled, platform-mediated avoidance task, we observed that pharmacological inactivation of the prelimbic prefrontal cortex (PL) delayed avoidance. Surprisingly, optogenetic silencing of PL glutamatergic neurons did not delay avoidance. Consistent with this, inhibitory but not excitatory responses of rostral PL neurons were associated with avoidance training. To test the importance of these inhibitory responses, we optogenetically stimulated PL neurons to counteract the tone-elicited reduction in firing rate. Photoactivation of rostral (but not caudal) PL neurons at 4 Hz impaired avoidance. These findings suggest that inhibitory responses of rostral PL neurons signal the avoidability of a potential threat and underscore the importance of designing behavioral optogenetic studies based on neuronal firing responses.
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Affiliation(s)
- Maria M Diehl
- Department of Psychiatry, University of Puerto Rico School of Medicine, San Juan, Puerto Rico.,Department of Anatomy & Neurobiology, University of Puerto Rico School of Medicine, San Juan, Puerto Rico
| | - Christian Bravo-Rivera
- Department of Psychiatry, University of Puerto Rico School of Medicine, San Juan, Puerto Rico.,Department of Anatomy & Neurobiology, University of Puerto Rico School of Medicine, San Juan, Puerto Rico
| | - Jose Rodriguez-Romaguera
- Department of Psychiatry, University of Puerto Rico School of Medicine, San Juan, Puerto Rico.,Department of Anatomy & Neurobiology, University of Puerto Rico School of Medicine, San Juan, Puerto Rico
| | - Pablo A Pagan-Rivera
- Department of Psychiatry, University of Puerto Rico School of Medicine, San Juan, Puerto Rico.,Department of Anatomy & Neurobiology, University of Puerto Rico School of Medicine, San Juan, Puerto Rico
| | - Anthony Burgos-Robles
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, United States
| | - Ciorana Roman-Ortiz
- Department of Psychiatry, University of Puerto Rico School of Medicine, San Juan, Puerto Rico.,Department of Anatomy & Neurobiology, University of Puerto Rico School of Medicine, San Juan, Puerto Rico
| | - Gregory J Quirk
- Department of Psychiatry, University of Puerto Rico School of Medicine, San Juan, Puerto Rico.,Department of Anatomy & Neurobiology, University of Puerto Rico School of Medicine, San Juan, Puerto Rico
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7
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Bangasser DA, Wiersielis KR. Sex differences in stress responses: a critical role for corticotropin-releasing factor. Hormones (Athens) 2018; 17:5-13. [PMID: 29858858 DOI: 10.1007/s42000-018-0002-z] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 11/03/2017] [Indexed: 12/19/2022]
Abstract
Rates of post-traumatic stress disorder, panic disorder, and major depression are higher in women than in men. Another shared feature of these disorders is that dysregulation of the stress neuropeptide, corticotropin-releasing factor (CRF), is thought to contribute to their pathophysiology. Therefore, sex differences in responses to CRF could contribute to this sex bias in disease prevalence. Here, we review emerging data from non-human animal models that reveal extensive sex differences in CRF functions ranging from its presynaptic regulation to its postsynaptic efficacy. Specifically, detailed are sex differences in the regulation of CRF-containing neurons and the amount of CRF that they produce. We also describe sex differences in CRF receptor expression, distribution, trafficking, and signaling. Finally, we highlight sex differences in the processes that mitigate the effects of CRF. In most cases, the identified sex differences can lead to increased stress sensitivity in females. Thus, the relevance of these differences for the increased risk of depression and anxiety disorders in women compared to men is also discussed.
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Affiliation(s)
- Debra A Bangasser
- Department of Psychology and Neuroscience Program, Temple University, 1701 North 13th Street, 873 Weiss Hall, Philadelphia, PA, 19122, USA.
| | - Kimberly R Wiersielis
- Department of Psychology and Neuroscience Program, Temple University, 1701 North 13th Street, 873 Weiss Hall, Philadelphia, PA, 19122, USA
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8
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Acute Stress Suppresses Synaptic Inhibition and Increases Anxiety via Endocannabinoid Release in the Basolateral Amygdala. J Neurosci 2017; 36:8461-70. [PMID: 27511017 DOI: 10.1523/jneurosci.2279-15.2016] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 06/25/2016] [Indexed: 01/09/2023] Open
Abstract
UNLABELLED Stress and glucocorticoids stimulate the rapid mobilization of endocannabinoids in the basolateral amygdala (BLA). Cannabinoid receptors in the BLA contribute to anxiogenesis and fear-memory formation. We tested for rapid glucocorticoid-induced endocannabinoid regulation of synaptic inhibition in the rat BLA. Glucocorticoid application to amygdala slices elicited a rapid, nonreversible suppression of spontaneous, but not evoked, GABAergic synaptic currents in BLA principal neurons; the effect was also seen with a membrane-impermeant glucocorticoid, but not with intracellular glucocorticoid application, implicating a membrane-associated glucocorticoid receptor. The glucocorticoid suppression of GABA currents was not blocked by antagonists of nuclear corticosteroid receptors, or by inhibitors of gene transcription or protein synthesis, but was blocked by inhibiting postsynaptic G-protein activity, suggesting a postsynaptic nongenomic steroid signaling mechanism that stimulates the release of a retrograde messenger. The rapid glucocorticoid-induced suppression of inhibition was prevented by blocking CB1 receptors and 2-arachidonoylglycerol (2-AG) synthesis, and it was mimicked and occluded by CB1 receptor agonists, indicating it was mediated by the retrograde release of the endocannabinoid 2-AG. The rapid glucocorticoid effect in BLA neurons in vitro was occluded by prior in vivo acute stress-induced, or prior in vitro glucocorticoid-induced, release of endocannabinoid. Acute stress also caused an increase in anxiety-like behavior that was attenuated by blocking CB1 receptor activation and inhibiting 2-AG synthesis in the BLA. Together, these findings suggest that acute stress causes a long-lasting suppression of synaptic inhibition in BLA neurons via a membrane glucocorticoid receptor-induced release of 2-AG at GABA synapses, which contributes to stress-induced anxiogenesis. SIGNIFICANCE STATEMENT We provide a cellular mechanism in the basolateral amygdala (BLA) for the rapid stress regulation of anxiogenesis in rats. We demonstrate a nongenomic glucocorticoid induction of long-lasting suppression of synaptic inhibition that is mediated by retrograde endocannabinoid release at GABA synapses. The rapid glucocorticoid-induced endocannabinoid suppression of synaptic inhibition is initiated by a membrane-associated glucocorticoid receptor in BLA principal neurons. We show that acute stress increases anxiety-like behavior via an endocannabinoid-dependent mechanism centered in the BLA. The stress-induced endocannabinoid modulation of synaptic transmission in the BLA contributes, therefore, to the stress regulation of anxiety, and may play a role in anxiety disorders of the amygdala.
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9
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Involvement of CRFR 1 in the Basolateral Amygdala in the Immediate Fear Extinction Deficit. eNeuro 2016; 3:eN-NWR-0084-16. [PMID: 27844053 PMCID: PMC5093152 DOI: 10.1523/eneuro.0084-16.2016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 10/12/2016] [Accepted: 10/12/2016] [Indexed: 11/21/2022] Open
Abstract
Several animal and clinical studies have highlighted the ineffectiveness of fear extinction sessions delivered shortly after trauma exposure. This phenomenon, termed the immediate extinction deficit, refers to situations in which extinction programs applied shortly after fear conditioning may result in the reduction of fear behaviors (in rodents, frequently measured as freezing responses to the conditioned cue) during extinction training, but failure to consolidate this reduction in the long term. The molecular mechanisms driving this immediate extinction resistance remain unclear. Here we present evidence for the involvement of the corticotropin releasing factor (CRF) system in the basolateral amygdala (BLA) in male Wistar rats. Intra-BLA microinfusion of the CRFR1 antagonist NBI30775 enhances extinction recall, whereas administration of the CRF agonist CRF6–33 before delayed extinction disrupts recall of extinction. We link the immediate fear extinction deficit with dephosphorylation of GluA1 glutamate receptors at Ser845 and enhanced activity of the protein phosphatase calcineurin in the BLA. Their reversal after treatment with the CRFR1 antagonist indicates their dependence on CRFR1 actions. These findings can have important implications for the improvement of therapeutic approaches to trauma, as well as furthering our understanding of the neurobiological mechanisms underlying fear-related disorders.
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10
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Cipriano AC, Gomes KS, Nunes-de-Souza RL. CRF receptor type 1 (but not type 2) located within the amygdala plays a role in the modulation of anxiety in mice exposed to the elevated plus maze. Horm Behav 2016; 81:59-67. [PMID: 27060334 DOI: 10.1016/j.yhbeh.2016.03.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 03/04/2016] [Accepted: 03/18/2016] [Indexed: 10/22/2022]
Abstract
The amygdala (Amy) is an important center that processes threatening stimuli. Among the neurotransmitters implicated in the control of emotional states, the corticotrophin releasing factor (CRF) is an important modulator, acting at CRF1 and CRF2 receptors. Few studies have investigated the role of CRF and its receptors in the Amy on anxiety in mice. Here, we investigated the effects of intra-Amy (aimed at the basolateral nucleus) injections of CRF (37.5 and 75pmol/0.1μl), urocortin 3 (UCn3, a selective CRF2 agonist; 4, 8, 16 or 24pmol/0.1μl), CP376395 (a selective CRF1 antagonist; 0.375, 0.75 or 1.5nmol/0.1μl), antisauvagine-30 (ASV-30, a selective CRF2 antagonist; 1 or 3nmol/0.1μl) on the behavior of mice exposed to the elevated plus maze (EPM). Both spatiotemporal (e.g., percentage of open-arm entries and percentage of open-arm time; %OE and %OT) and complementary [e.g., frequency of protected and unprotected stretched attend postures (pSAP and uSAP) and head dips (pHD and uHD); frequency and time spent on open arm end exploration (OAEE)] measures were recorded during a 5-min test in the EPM. While intra-Amy injections of CRF decreased %OE, %OT and OAEE, suggesting an anxiogenic-like action, UCn3 (all doses) did not change any behavior. In contrast, injections of CP376395 (0.75nmol) produced an anxiolytic-like effect, by increasing %OT and OAEE and decreasing pSAP and pHD. Neither spatiotemporal nor complementary measures were changed by intra-Amy ASV-30. These results suggest that CRF plays a marked anxiogenic role at CRF1 receptors in the amygdala of mice exposed to the EPM.
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Affiliation(s)
- Ana Cláudia Cipriano
- School of Pharmaceutical Sciences, Univ. Estadual Paulista - UNESP, 14800-903, Araraquara, SP, Brazil; Joint Graduate Program in Physiological Sciences, UFSCar/UNESP, São Carlos, SP 13565-905, Brazil.
| | - Karina Santos Gomes
- School of Pharmaceutical Sciences, Univ. Estadual Paulista - UNESP, 14800-903, Araraquara, SP, Brazil.
| | - Ricardo Luiz Nunes-de-Souza
- School of Pharmaceutical Sciences, Univ. Estadual Paulista - UNESP, 14800-903, Araraquara, SP, Brazil; Joint Graduate Program in Physiological Sciences, UFSCar/UNESP, São Carlos, SP 13565-905, Brazil.
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11
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Gafford GM, Ressler KJ. GABA and NMDA receptors in CRF neurons have opposing effects in fear acquisition and anxiety in central amygdala vs. bed nucleus of the stria terminalis. Horm Behav 2015; 76:136-42. [PMID: 25888455 PMCID: PMC4844457 DOI: 10.1016/j.yhbeh.2015.04.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Revised: 03/29/2015] [Accepted: 04/06/2015] [Indexed: 01/07/2023]
Abstract
This article is part of a Special Issue "SBN 2014". Beginning with Vale and Colleagues in 1981, corticotropin releasing factor (CRF) also called corticotropin releasing hormone (CRH) has repeatedly been identified as an important contributor to fear and anxiety behavior. These findings have proven useful to further our understanding of disorders that have significant fear-dysregulation, such as post-traumatic stress, as well as other stress- and anxiety-related disorders. Unfortunately, the data are not all in agreement. In particular the role of CRF in fear learning is controversial, with studies pointing to contradictory effects from CRF manipulation even within the same brain structure. Further, very few studies address the potentially promising role of CRF manipulation in fear extinction behavior. Here, we briefly review the role of CRF in anxiety, fear learning and extinction, focusing on recent cell-type and neurotransmitter-specific studies in the amygdala and bed nucleus of the stria terminalis (BNST) that may help to synthesize the available data on the role of CRF in fear and anxiety-related behaviors.
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Affiliation(s)
- Georgette M Gafford
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA; Center for Behavioral Neuroscience, Yerkes National Primate Research Center, Atlanta, GA, USA
| | - Kerry J Ressler
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA; Center for Behavioral Neuroscience, Yerkes National Primate Research Center, Atlanta, GA, USA; Howard Hughes Medical Institute, Bethesda, MD, USA.
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12
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Bangasser DA, Kawasumi Y. Cognitive disruptions in stress-related psychiatric disorders: A role for corticotropin releasing factor (CRF). Horm Behav 2015; 76:125-35. [PMID: 25888454 PMCID: PMC4605842 DOI: 10.1016/j.yhbeh.2015.04.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 04/06/2015] [Accepted: 04/07/2015] [Indexed: 12/28/2022]
Abstract
This article is part of a Special Issue "SBN 2014". Stress is a potential etiology contributor to both post-traumatic stress disorders (PTSD) and major depression. One stress-related neuropeptide that is hypersecreted in these disorders is corticotropin releasing factor (CRF). Dysregulation of CRF has long been linked to the emotion and mood symptoms that characterize PTSD and depression. However, the idea that CRF also mediates the cognitive disruptions observed in patients with these disorders has received less attention. Here we review literature indicating that CRF can alter cognitive functions. Detailed are anatomical studies revealing that CRF is poised to modulate regions required for learning and memory. We also describe preclinical behavioral studies that demonstrate CRF's ability to alter fear conditioning, impair memory consolidation, and alter a number of executive functions, including attention and cognitive flexibility. The implications of these findings for the etiology and treatment of the cognitive impairments observed in stress-related psychiatric disorders are described.
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Affiliation(s)
- Debra A Bangasser
- Department of Psychology and Neuroscience Program, Temple University, Philadelphia, PA, USA.
| | - Yushi Kawasumi
- Department of Psychology and Neuroscience Program, Temple University, Philadelphia, PA, USA
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13
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Gilman TL, DaMert JP, Meduri JD, Jasnow AM. Grin1 deletion in CRF neurons sex-dependently enhances fear, sociability, and social stress responsivity. Psychoneuroendocrinology 2015; 58:33-45. [PMID: 25938741 DOI: 10.1016/j.psyneuen.2015.04.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 04/13/2015] [Accepted: 04/13/2015] [Indexed: 12/20/2022]
Abstract
The corticotropin releasing factor (CRF) system plays a critical role in responses to stressful stimuli, and is expressed in many areas of the brain involved in processing fear, anxiety, and social behaviors. To better understand the mechanisms by which the CRF system modulates responses to stressful events and social stimuli, we employed a mouse model that selectively disrupts NMDA receptor function via NMDA receptor subunit NR1 (Grin1) knockout specifically in Cre-expressing CRF neurons. These animals (Cre+/(fGrin1+)) were compared with littermates lacking Cre expression (Cre-/(fGrin1+)). Following cue discrimination fear conditioning, male Cre+/(fGrin1+) mice showed increased fear expression to the tone paired with a foot shock (CS+) while still discriminating the CS+ from a tone never paired with a foot shock (CS-). In contrast to males, female mice learned and discriminated fear cues equivalently across the genotypes. Similarly, no genotype differences in sociability or social novelty were observed in female mice, but Cre+/(fGrin1+) males displayed greater naive sociability and preference for social novelty than Cre-/(fGrin1+) littermates. Furthermore, the level of social withdrawal exhibited by male Cre+/(fGrin1+) mice susceptible to social defeat stress relative to same genotype controls was significantly more pronounced than that displayed by susceptible Cre-/(fGrin1+) mice compared to control Cre-/(fGrin1+) mice. Together, these results demonstrate increased fear, social, and stress responsiveness specifically in male Cre+/(fGrin1+) mice. Our findings indicate that NMDA-mediated glutamatergic regulation of CRF neurons is important for appropriately regulating fear and social responses, likely functioning to promote survival under aversive circumstances.
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Affiliation(s)
- T Lee Gilman
- Department of Psychological Sciences, Kent State University, Kent, 44242, OH, USA.
| | - Jeffrey P DaMert
- Department of Psychological Sciences, Kent State University, Kent, 44242, OH, USA.
| | - Jeremy D Meduri
- Department of Psychological Sciences, Kent State University, Kent, 44242, OH, USA.
| | - Aaron M Jasnow
- Department of Psychological Sciences, Kent State University, Kent, 44242, OH, USA.
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14
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Meyer RM, Burgos-Robles A, Liu E, Correia SS, Goosens KA. A ghrelin-growth hormone axis drives stress-induced vulnerability to enhanced fear. Mol Psychiatry 2014; 19:1284-94. [PMID: 24126924 PMCID: PMC3988273 DOI: 10.1038/mp.2013.135] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 08/20/2013] [Accepted: 09/09/2013] [Indexed: 01/05/2023]
Abstract
Hormones in the hypothalamus-pituitary-adrenal (HPA) axis mediate many of the bodily responses to stressors, yet there is no clear relationship between the levels of these hormones and stress-associated mental illnesses such as posttraumatic stress disorder (PTSD). Therefore, other hormones are likely to be involved in this effect of stress. Here we used a rodent model of PTSD in which rats repeatedly exposed to a stressor display heightened fear learning following auditory Pavlovian fear conditioning. Our results show that stress-related increases in circulating ghrelin, a peptide hormone, are necessary and sufficient for stress-associated vulnerability to exacerbated fear learning and these actions of ghrelin occur in the amygdala. Importantly, these actions are also independent of the classic HPA stress axis. Repeated systemic administration of a ghrelin receptor agonist enhanced fear memory but did not increase either corticotropin-releasing factor (CRF) or corticosterone. Repeated intraamygdala infusion of a ghrelin receptor agonist produced a similar enhancement of fear memory. Ghrelin receptor antagonism during repeated stress abolished stress-related enhancement of fear memory without blunting stress-induced corticosterone release. We also examined links between ghrelin and growth hormone (GH), a major downstream effector of the ghrelin receptor. GH protein was upregulated in the amygdala following chronic stress, and its release from amygdala neurons was enhanced by ghrelin receptor stimulation. Virus-mediated overexpression of GH in the amygdala was also sufficient to increase fear. Finally, virus-mediated overexpression of a GH receptor antagonist was sufficient to block the fear-enhancing effects of repeated ghrelin receptor stimulation. Thus, ghrelin requires GH in the amygdala to exert fear-enhancing effects. These results suggest that ghrelin mediates a novel branch of the stress response and highlight a previously unrecognized role for ghrelin and growth hormone in maladaptive changes following prolonged stress.
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Affiliation(s)
- Retsina M. Meyer
- McGovern Institute for Brain Research and the Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 43 Vassar St, Cambridge, MA 02139, USA
| | - Anthony Burgos-Robles
- McGovern Institute for Brain Research and the Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 43 Vassar St, Cambridge, MA 02139, USA
| | - Elizabeth Liu
- McGovern Institute for Brain Research and the Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 43 Vassar St, Cambridge, MA 02139, USA
| | - Susana S. Correia
- McGovern Institute for Brain Research and the Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 43 Vassar St, Cambridge, MA 02139, USA
| | - Ki A. Goosens
- McGovern Institute for Brain Research and the Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 43 Vassar St, Cambridge, MA 02139, USA
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15
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The hypocretin/orexin system mediates the extinction of fear memories. Neuropsychopharmacology 2014; 39:2732-41. [PMID: 24930888 PMCID: PMC4200503 DOI: 10.1038/npp.2014.146] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 05/15/2014] [Accepted: 06/09/2014] [Indexed: 01/01/2023]
Abstract
Anxiety disorders are often associated with an inability to extinguish learned fear responses. The hypocretin/orexin system is involved in the regulation of emotional states and could also participate in the consolidation and extinction of aversive memories. Using hypocretin receptor-1 and hypocretin receptor-2 antagonists, hypocretin-1 and hypocretin-2 peptides, and hypocretin receptor-1 knockout mice, we investigated the role of the hypocretin system in cue- and context-dependent fear conditioning and extinction. Hypocretins were crucial for the consolidation of fear conditioning, and this effect was mainly observed in memories with a high emotional component. Notably, after the acquisition of fear memory, hypocretin receptor-1 blockade facilitated fear extinction, whereas hypocretin-1 administration impaired this extinction process. The extinction-facilitating effects of the hypocretin receptor-1 antagonist SB334867 were associated with increased expression of cFos in the basolateral amygdala and the infralimbic cortex. Intra-amygdala, but neither intra-infralimbic prefrontal cortex nor intra-dorsohippocampal infusion of SB334867 enhanced fear extinction. These results reveal a key role for hypocretins in the extinction of aversive memories and suggest that hypocretin receptor-1 blockade could represent a novel therapeutic target for the treatment of diseases associated with inappropriate retention of fear, such as post-traumatic stress disorder and phobias.
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16
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Abiri D, Douglas CE, Calakos KC, Barbayannis G, Roberts A, Bauer EP. Fear extinction learning can be impaired or enhanced by modulation of the CRF system in the basolateral nucleus of the amygdala. Behav Brain Res 2014; 271:234-9. [PMID: 24946071 PMCID: PMC5126972 DOI: 10.1016/j.bbr.2014.06.021] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 05/14/2014] [Accepted: 06/09/2014] [Indexed: 02/05/2023]
Abstract
The neuropeptide corticotropin-releasing factor (CRF) is released during periods of anxiety and modulates learning and memory formation. One region with particularly dense concentrations of CRF receptors is the basolateral nucleus of the amygdala (BLA), a critical structure for both Pavlovian fear conditioning and fear extinction. While CRF has the potential to modify amygdala-dependent learning, its effect on fear extinction has not yet been assessed. In the present study, we examined the modulatory role of CRF on within-session extinction and fear extinction consolidation. Intra-BLA infusions of the CRF binding protein ligand inhibitor CRF(6-33) which increases endogenous levels of free CRF, or intra-BLA infusions of exogenous CRF made prior to fear extinction learning did not affect either fear expression or within-session extinction learning. However, when these animals were tested twenty-four hours later, drug free, they showed impairments in extinction memory. Conversely, intra-BLA infusions of the CRF receptor antagonist α-helical CRF(9-41) enhanced memory of fear extinction. These results suggest that increased CRF levels within the BLA at the time of fear extinction learning actively impair the consolidation of long-term fear extinction.
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Affiliation(s)
- Dina Abiri
- Barnard College, Columbia University, 3009 Broadway, New York, NY 10027, United States
| | - Christina E Douglas
- Barnard College, Columbia University, 3009 Broadway, New York, NY 10027, United States
| | - Katina C Calakos
- Barnard College, Columbia University, 3009 Broadway, New York, NY 10027, United States
| | - Georgia Barbayannis
- Barnard College, Columbia University, 3009 Broadway, New York, NY 10027, United States
| | - Andrea Roberts
- Barnard College, Columbia University, 3009 Broadway, New York, NY 10027, United States
| | - Elizabeth P Bauer
- Barnard College, Columbia University, 3009 Broadway, New York, NY 10027, United States.
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17
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Merali Z, Mountney C, Kent P, Anisman H. Activation of gastrin-releasing peptide receptors at the infralimbic cortex elicits gastrin-releasing peptide release at the basolateral amygdala: implications for conditioned fear. Neuroscience 2013; 243:97-103. [PMID: 23567813 DOI: 10.1016/j.neuroscience.2013.03.056] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 03/22/2013] [Accepted: 03/24/2013] [Indexed: 10/27/2022]
Abstract
The basolateral amygdala (BLA) and infralimbic (IL) cortex share strong reciprocal interconnections and are key structures in conditioned fear circuitry. Gastrin-releasing peptide (GRP) or its receptor antagonists can modulate the conditioned fear response when exogenously administered at either of these sites, and increased release of GRP at the BLA occurs in response to conditioned fear recall. The present study sought to determine whether a functional pathway utilizing GRP exists between the IL cortex and BLA and whether this pathway is also influenced by amygdala corticotropin-releasing factor (CRF) release. To this end, we assessed the effects of intra-IL cortex injection of GRP or GRP co-administered with a receptor antagonist, RC-3095, on the downstream release of GRP and/or CRF at the BLA. Results showed that microinjection of GRP at the IL cortex increased the release of GRP, but not CRF, at the BLA, an effect blocked by co-administration of RC-3095. Administration of RC-3095 into the IL cortex on its own, however, also elicited the release of GRP (but not CRF) at the BLA. These findings suggest that a functional pathway utilizing GRP (among other factors) exists between the IL cortex and BLA that may be relevant to conditioned fear, but that GRP and CRF do not interact within this circuitry. Moreover, the finding that the release profile of GRP was similar following administration of either GRP or its receptor antagonist, lends support to the view that RC-3095 has partial agonist properties. Together these findings provide further evidence for the involvement of GRP in fear and anxiety-related disorders.
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Affiliation(s)
- Z Merali
- School of Psychology, University of Ottawa, Ottawa, Ontario, Canada K1N 6N5.
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18
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Bangasser DA. Sex differences in stress-related receptors: ″micro″ differences with ″macro″ implications for mood and anxiety disorders. Biol Sex Differ 2013; 4:2. [PMID: 23336736 PMCID: PMC3556142 DOI: 10.1186/2042-6410-4-2] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 12/27/2012] [Indexed: 11/10/2022] Open
Abstract
Stress-related psychiatric disorders, such as unipolar depression and post-traumatic stress disorder (PTSD), occur more frequently in women than in men. Emerging research suggests that sex differences in receptors for the stress hormones, corticotropin releasing factor (CRF) and glucocorticoids, contribute to this disparity. For example, sex differences in CRF receptor binding in the amygdala of rats may predispose females to greater anxiety following stressful events. Additionally, sex differences in CRF receptor signaling and trafficking in the locus coeruleus arousal center combine to make females more sensitive to low levels of CRF, and less adaptable to high levels. These receptor differences in females could lead to hyperarousal, a dysregulated state associated with symptoms of depression and PTSD. Similar to the sex differences observed in CRF receptors, sex differences in glucocorticoid receptor (GR) function also appear to make females more susceptible to dysregulation after a stressful event. Following hypothalamic pituitary adrenal axis activation, GRs are critical to the negative feedback process that inhibits additional glucocorticoid release. Compared to males, female rats have fewer GRs and impaired GR translocation following chronic adolescent stress, effects linked to slower glucocorticoid negative feedback. Thus, under conditions of chronic stress, attenuated negative feedback in females would result in hypercortisolemia, an endocrine state thought to cause depression. Together, these studies suggest that sex differences in stress-related receptors shift females more easily into a dysregulated state of stress reactivity, linked to the development of mood and anxiety disorders. The implications of these receptor sex differences for the development of novel pharmacotherapies are also discussed.
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Affiliation(s)
- Debra A Bangasser
- Department of Psychology and Neuroscience Program, Temple University, 1701 North 13th Street, 873 Weiss Hall, Philadelphia, 19122, PA.
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