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Groenink L, Verdouw PM, Zhao Y, Ter Heegde F, Wever KE, Bijlsma EY. Pharmacological modulation of conditioned fear in the fear-potentiated startle test: a systematic review and meta-analysis of animal studies. Psychopharmacology (Berl) 2023; 240:2361-2401. [PMID: 36651922 PMCID: PMC10593622 DOI: 10.1007/s00213-022-06307-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 12/21/2022] [Indexed: 01/19/2023]
Abstract
RATIONALE AND OBJECTIVES Fear conditioning is an important aspect in the pathophysiology of anxiety disorders. The fear-potentiated startle test is based on classical fear conditioning and over the years, a broad range of drugs have been tested in this test. Synthesis of the available data may further our understanding of the neurotransmitter systems that are involved in the expression of conditioned fear. METHODS Following a comprehensive search in Medline and Embase, we included 68 research articles that reported on 103 drugs, covering 56 different drug classes. The systematic review was limited to studies using acute, systemic drug administration in naive animals. RESULTS Qualitative data synthesis showed that most clinically active anxiolytics, but not serotonin-reuptake inhibitors, reduced cued fear. Anxiogenic drugs increased fear potentiation in 35% of the experiments, reduced fear potentiation in 29% of the experiments, and were without effect in 29% of the experiments. Meta-analyses could be performed for five drug classes and showed that benzodiazepines, buspirone, 5-HT1A agonists, 5-HT1A antagonists, and mGluR2,3 agonists reduced cued conditioned fear. The non-cued baseline startle response, which may reflect contextual anxiety, was only significantly reduced by benzodiazepines and 5-HT1A antagonists. No associations were found between drug effects and methodological characteristics, except for strain. CONCLUSIONS The fear-potentiated startle test appears to have moderate to high predictive validity and may serve as a valuable tool for the development of novel anxiolytics. Given the limited available data, the generally low study quality and high heterogeneity additional studies are warranted to corroborate the findings of this review.
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Affiliation(s)
- Lucianne Groenink
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands.
| | - P Monika Verdouw
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands
| | - Yulong Zhao
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands
| | - Freija Ter Heegde
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands
| | - Kimberley E Wever
- Department of Anaesthesiology, Pain and Palliative Medicine, Radboud Institute for Health Sciences, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA, Nijmegen, The Netherlands
| | - Elisabeth Y Bijlsma
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands
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2
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Fukunaga K, Yabuki Y, Takahata I, Matsuo K. [Neurological mechanism and therapeutic strategy for posttraumatic stress disorders]. Nihon Yakurigaku Zasshi 2019; 152:194-201. [PMID: 30298841 DOI: 10.1254/fpj.152.194] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Posttraumatic stress disorder (PTSD) is most often induced by traumatic events and serious public health problems. PTSD is characterized by excessive response to contextual memory and impaired fear extinction and also associated with mild cognitive impairment, attention and learning deficits. Clinical and animal studies suggest that increased susceptibility of emotion- and fear-related neuronal circuits, including those in the amygdala, prefrontal cortex and hippocampus, contributes to development and retention of PTSD symptoms. However, mechanisms underlying this susceptibility to fear are not known and the useful therapeutic approaches are limited. Recently, there have been reports that ω3 LCPUFA supplementation can prevent development of PTSD and significantly ameliorate symptoms in patients with PTSD after accidental injury such as motor vehicle accidents and natural calamities. Importantly, Fabp7 null mice exhibit enhancement of fear memory consolidation and anxiety-related behaviors that resemble PTSD-like behaviors in humans. In this review, we focused behavioral phenotype of PTSD in Fabp3 null mice. The Fabp3 null mice exhibit cognitive deficits, hyperlocomotion and impaired fear extinction, and thus show PTSD-like behaviors. Chronic administration of ramelteon, a melatonin receptor agonist, improved all PTSD-like behaviors tested in Fabp3-/- mice. Relevant to mechanisms underlying impaired fear extinction, we observed that Ca2+/calmodulin-dependent protein kinase II (CaMKII) autophosphorylation increases in the basolateral amygdala (BLA) but remained unchanges in the hippocampus of Fabp3-/- mice. Likewise, the number of c-Fos positive neurons in BLA significantly increased after exposure to contextual fear conditions. Finally, chronic ramelteon administration restored abnormal c-Fos expression and CaMKII autophosphorylation in the BLA of Fabp3-/- mice. Taken together, Fabp3-/- mice show PTSD-like behaviors, and ramelteon is an attractive candidate for PTSD therapeutics in human.
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Affiliation(s)
- Kohji Fukunaga
- Department of Pharmacology, Tohoku University Graduate School of Pharmaceutical Sciences
| | - Yasushi Yabuki
- Department of Pharmacology, Tohoku University Graduate School of Pharmaceutical Sciences
| | - Ibuki Takahata
- Department of Pharmacology, Tohoku University Graduate School of Pharmaceutical Sciences
| | - Kazuya Matsuo
- Department of Pharmacology, Tohoku University Graduate School of Pharmaceutical Sciences
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3
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Park SC, Kim YK. A Novel Bio-Psychosocial-Behavioral Treatment Model of Panic Disorder. Psychiatry Investig 2019; 16:4-15. [PMID: 30301303 PMCID: PMC6354044 DOI: 10.30773/pi.2018.08.21.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 08/09/2018] [Accepted: 08/21/2018] [Indexed: 12/11/2022] Open
Abstract
To conceptualize a novel bio-psychosocial-behavioral treatment model of panic disorder (PD), it is necessary to completely integrate behavioral, psychophysiological, neurobiological, and genetic data. Molecular genetic research on PD is specifically focused on neurotransmitters, including serotonin, neuropeptides, glucocorticoids, and neurotrophins. Although pharmacological interventions for PD are currently available, the need for more effective, faster-acting, and more tolerable pharmacological interventions is unmet. Thus, glutamatergic receptor modulators, orexin receptor antagonists, corticotrophin-releasing factor 1 receptor antagonists, and other novel mechanism-based anti-panic therapeutics have been proposed. Research on the neural correlates of PD is focused on the dysfunctional "cross-talk" between emotional drive (limbic structure) and cognitive inhibition (prefrontal cortex) and the fear circuit, which includes the amygdala-hippocampus-prefrontal axis. The neural perspective regarding PD supports the idea that cognitive-behavioral therapy normalizes alterations in top-down cognitive processing, including increased threat expectancy and attention to threat. Consistent with the concept of "personalized medicine," it is speculated that Research Domain Criteria can enlighten further treatments targeting dysfunctions underlying PD more precisely and provide us with better definitions of moderators used to identify subgroups according to different responses to treatment. Structuring of the "negative valence systems" domain, which includes fear/anxiety, is required to define PD. Therefore, targeting glutamate- and orexin-related molecular mechanisms associated with the fear circuit, which includes the amygdala-hippocampus-prefrontal cortex axis, is required to define a novel bio-psychosocial-behavioral treatment model of PD.
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Affiliation(s)
- Seon-Cheol Park
- Department of Psychiatry, Inje University College of Medicine and Haeundae Paik Hospital, Busan, Republic of Korea
| | - Yong-Ku Kim
- Department of Psychiatry, College of Medicine, Korea University, Ansan Hospital, Ansan, Republic of Korea
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4
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Murkar ALA, De Koninck J. Consolidative mechanisms of emotional processing in REM sleep and PTSD. Sleep Med Rev 2018; 41:173-184. [PMID: 29628334 DOI: 10.1016/j.smrv.2018.03.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 02/19/2018] [Accepted: 03/05/2018] [Indexed: 12/30/2022]
Abstract
Research suggests sleep plays a role in the consolidation of recently acquired memories for long-term storage. rapid eye movement (REM) sleep has been shown to play a complex role in emotional-memory processing, and may be involved in subsequent waking-day emotional reactivity and amygdala responsivity. Interaction of the hippocampus and basolateral amygdala with the medial-prefrontal cortex is associated with sleep-dependent learning and emotional memory processing. REM is also implicated in post-traumatic stress disorder (PTSD), which is characterized by sleep disturbance, heightened reactivity to fearful stimuli, and nightmares. Many suffers of PTSD also exhibit dampened medial-prefrontal cortex activity. However, the effects of PTSD-related brain changes on REM-dependent consolidation or the notion of 'over-consolidation' (strengthening of memory traces to such a degree that they become resistant to extinction) have been minimally explored. Here, we posit that (in addition to sleep architecture changes) the memory functions of REM must also be altered in PTSD. We propose a model of REM-dependent consolidation of learned fear in PTSD and examine how PTSD-related brain changes might interact with fear learning. We argue that reduced efficacy of inhibitory medial-prefrontal pathways may lead to maladaptive processing of traumatic memories in the early stages of consolidation after trauma.
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Affiliation(s)
- Anthony L A Murkar
- School of Psychology, University of Ottawa, Canada; The Royal's Institute of Mental Health Research affiliated with the University of Ottawa, Canada.
| | - Joseph De Koninck
- School of Psychology, University of Ottawa, Canada; The Royal's Institute of Mental Health Research affiliated with the University of Ottawa, Canada.
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5
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Savage JE, Sawyers C, Roberson-Nay R, Hettema JM. The genetics of anxiety-related negative valence system traits. Am J Med Genet B Neuropsychiatr Genet 2017; 174:156-177. [PMID: 27196537 PMCID: PMC5349709 DOI: 10.1002/ajmg.b.32459] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 05/05/2016] [Indexed: 01/11/2023]
Abstract
NIMH's Research Domain Criteria (RDoC) domain of negative valence systems (NVS) captures constructs of negative affect such as fear and distress traditionally subsumed under the various internalizing disorders. Through its aims to capture dimensional measures that cut across diagnostic categories and are linked to underlying neurobiological systems, a large number of phenotypic constructs have been proposed as potential research targets. Since "genes" represent a central "unit of analysis" in the RDoC matrix, it is important for studies going forward to apply what is known about the genetics of these phenotypes as well as fill in the gaps of existing knowledge. This article reviews the extant genetic epidemiological data (twin studies, heritability) and molecular genetic association findings for a broad range of putative NVS phenotypic measures. We find that scant genetic epidemiological data is available for experimentally derived measures such as attentional bias, peripheral physiology, or brain-based measures of threat response. The molecular genetic basis of NVS phenotypes is in its infancy, since most studies have focused on a small number of candidate genes selected for putative association to anxiety disorders (ADs). Thus, more research is required to provide a firm understanding of the genetic aspects of anxiety-related NVS constructs. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Jeanne E. Savage
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA
| | - Chelsea Sawyers
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA
| | - Roxann Roberson-Nay
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA,Department of Psychiatry, Virginia Commonwealth University, Richmond, VA
| | - John M. Hettema
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA,Department of Psychiatry, Virginia Commonwealth University, Richmond, VA
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6
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Heitland I, Groenink L, van Gool JM, Domschke K, Reif A, Baas JMP. Human fear acquisition deficits in relation to genetic variants of the corticotropin-releasing hormone receptor 1 and the serotonin transporter--revisited. GENES BRAIN AND BEHAVIOR 2016; 15:209-20. [PMID: 26643280 DOI: 10.1111/gbb.12276] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 08/22/2015] [Accepted: 11/12/2015] [Indexed: 12/26/2022]
Abstract
We recently showed that a genetic polymorphism (rs878886) in the human corticotropin-releasing hormone receptor 1 (CRHR1) is associated with reduced fear-conditioned responses to a threat cue. This is a potentially important finding considering that the failure to acquire fear contingencies can leave an individual in a maladaptive state of more generalized anxiety. Consistent with that idea, the CRHR1-dependent fear acquisition deficit translated into heightened contextual anxiety when taking genetic variability within the serotonin transporter long polymorphic region (5-HTTLPR) into account. To replicate our previous findings, we conducted a replication study in 224 healthy medication-free human subjects using the exact same cue and context virtual reality fear-conditioning procedure as in study by Heitland et al. (2013). In the replication study, consistent with the original findings, CRHR1 rs878886 G-allele carriers showed reduced acquisition of cue-specific fear-conditioned responses compared with C/C homozygotes. Also, in this larger sample the cue acquisition deficit of G-allele carriers translated into heightened contextual anxiety, even independent of 5-HTT gene variation. In contrast to our earlier findings, there was an additional interaction effect of CRHR1 rs878886 and the triallelic 5-HTTLPR/rs25531 variant on cued fear acquisition. In summary, this study replicated the initially reported association of the CRHR1 rs878886 G-allele with cued fear acquisition deficits, albeit with a different pattern of results regarding the interaction with 5-HTT variation. This further supports the notion that the human corticotropin-releasing hormone plays a role in the acquisition of fears.
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Affiliation(s)
- I Heitland
- Department of Experimental Psychology, Utrecht University, Utrecht, The Netherlands.,Helmholtz Research Institute, Utrecht, The Netherlands
| | - L Groenink
- Department of Pharmacology, Utrecht Institute of Pharmaceutical Sciences, Utrecht, The Netherlands
| | - J M van Gool
- Department of Experimental Psychology, Utrecht University, Utrecht, The Netherlands
| | - K Domschke
- Department of Psychiatry, Psychosomatics and Psychotherapy, University of Würzburg, Würzburg, Germany
| | - A Reif
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - J M P Baas
- Department of Experimental Psychology, Utrecht University, Utrecht, The Netherlands.,Helmholtz Research Institute, Utrecht, The Netherlands
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7
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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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8
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Santos M, D'Amico D, Dierssen M. From neural to genetic substrates of panic disorder: Insights from human and mouse studies. Eur J Pharmacol 2015; 759:127-41. [PMID: 25818748 DOI: 10.1016/j.ejphar.2015.03.039] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Revised: 01/15/2015] [Accepted: 03/12/2015] [Indexed: 01/30/2023]
Abstract
Fear is an ancestral emotion, an intrinsic defensive response present in every organism. Although fear is an evolutionarily advantageous emotion, under certain pathologies such as panic disorder it might become exaggerated and non-adaptive. Clinical and preclinical work pinpoints that changes in cognitive processes, such as perception and interpretation of environmental stimuli that rely on brain regions responsible for high-level function, are essential for the development of fear-related disorders. This review focuses on the involvement of cognitive function to fear circuitry disorders. Moreover, we address how animal models are contributing to understand the involvement of human candidate genes to pathological fear and helping achieve progress in this field. Multidisciplinary approaches that integrate human genetic findings with state of the art genetic mouse models will allow to elucidate the mechanisms underlying pathology and to develop new strategies for therapeutic targeting.
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Affiliation(s)
- Mónica Santos
- Cellular & Systems Neurobiology, Systems Biology Program, Center for Genomic Regulation (CRG), E-08003 Barcelona, Spain; Universitat Pompeu Fabra (UPF), E-08003 Barcelona, Spain; CIBER de Enfermedades Raras (CIBERER), E-08003 Barcelona, Spain; Institute of Biology, Otto-von-Guericke University, 39120 Magdeburg, Germany.
| | - Davide D'Amico
- Cellular & Systems Neurobiology, Systems Biology Program, Center for Genomic Regulation (CRG), E-08003 Barcelona, Spain; Universitat Pompeu Fabra (UPF), E-08003 Barcelona, Spain; CIBER de Enfermedades Raras (CIBERER), E-08003 Barcelona, Spain; ZeClinics SL, E-08001 Barcelona, Spain.
| | - Mara Dierssen
- Cellular & Systems Neurobiology, Systems Biology Program, Center for Genomic Regulation (CRG), E-08003 Barcelona, Spain; Universitat Pompeu Fabra (UPF), E-08003 Barcelona, Spain; CIBER de Enfermedades Raras (CIBERER), E-08003 Barcelona, Spain.
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9
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Flandreau E, Risbrough V, Lu A, Ableitner M, Geyer MA, Holsboer F, Deussing JM. Cell type-specific modifications of corticotropin-releasing factor (CRF) and its type 1 receptor (CRF1) on startle behavior and sensorimotor gating. Psychoneuroendocrinology 2015; 53:16-28. [PMID: 25575243 PMCID: PMC4364548 DOI: 10.1016/j.psyneuen.2014.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 11/25/2014] [Accepted: 12/03/2014] [Indexed: 10/24/2022]
Abstract
The corticotropin-releasing factor (CRF) family of peptides and receptors coordinates the mammalian endocrine, autonomic, and behavioral responses to stress. Excessive CRF production has been implicated in the etiology of stress-sensitive psychiatric disorders such as posttraumatic stress disorder (PTSD), which is associated with alterations in startle plasticity. The CRF family of peptides and receptors mediate acute startle response changes during stress, and chronic CRF activation can induce startle abnormalities. To determine what neural circuits modulate startle in response to chronic CRF activation, transgenic mice overexpressing CRF throughout the central nervous system (CNS; CRF-COE(CNS)) or restricted to inhibitory GABAergic neurons (CRF-COE(GABA)) were compared across multiple domains of startle plasticity. CRF overexpression throughout the CNS increased startle magnitude and reduced ability to inhibit startle (decreased habituation and decreased prepulse inhibition (PPI)), similar to previous reports of exogenous effects of CRF. Conversely, CRF overexpression confined to inhibitory neurons decreased startle magnitude but had no effect on inhibitory measures. Acute CRF receptor 1 (CRF1) antagonist treatment attenuated only the effects on startle induced by CNS-specific CRF overexpression. Specific deletion of CRF1 receptors from forebrain principal neurons failed to alter the effects of exogenous CRF or stress on startle, suggesting that these CRF1 expressing neurons are not required for CRF-induced changes in startle behaviors. These data indicate that the effects of CRF activation on startle behavior utilize an extensive neural circuit that includes both forebrain and non-forebrain regions. Furthermore, these findings suggest that the neural source of increased CRF release determines the startle phenotype elicited. It is conceivable that this may explain why disorders characterized by increased CRF in cerebrospinal fluid (e.g. PTSD and major depressive disorder) have distinct symptom profiles in terms of startle reactivity.
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Affiliation(s)
| | - Victoria Risbrough
- Veterans Administration Center of Excellence for Stress and Mental Health, 3350 La Jolla Village Drive San Diego, CA 92161, USA.
| | - Ailing Lu
- Unit of Innate Immunity, Key Laboratory of Molecular Virology and Immunology Institut Pasteur of Shanghai, Chinese Academy of Sciences. 320 Yue Yang Road, Shanghai, 200031; China. Phone/Fax: 86-21-54923102/54923101
| | - Martin Ableitner
- Max Planck Institute of Psychiatry, Kraepelinstrasse 2-10 D-80804, Munich Phone: +49 (0)89 / 30622-645 Fax: +49 (0)89 / 30622-610
| | - Mark A Geyer
- Department of Psychiatry University of California San Diego 9500 Gilman Drive MC 0804 La Jolla, CA 92093-0804 ph (619)543-3582 fx (619)543-2493
| | - Florian Holsboer
- Max Planck Institute of Psychiatry Kraepelinstr. 2-10 80804 Munich, Germany Phone: +49-89-30622-220 Fax: +49-89-30622-483
| | - Jan M Deussing
- Department Stress Neurobiology and Neurogenetics Max Planck Institute of Psychiatry Kraepelinstrasse 2-10 D-80804, Munich Phone: +49 (0)89 / 30622-639 Fax: +49 (0)89 / 30622-610
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10
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Abstract
Our dynamic environment regularly exposes us to potentially life-threatening challenges or stressors. To answer these challenges and maintain homeostasis, the stress response, an innate coordinated engagement of central and peripheral neural systems is initiated. Although essential for survival, the inappropriate initiation of the stress response or its continuation after the stressor is terminated has pathological consequences that have been linked to diverse neuropsychiatric and medical diseases. Substantial individual variability exists in the pathological consequences of stressors. A theme of this Special Issue is that elucidating the basis of individual differences in resilience or its flipside, vulnerability, will greatly advance our ability to prevent and treat stress-related diseases. This can be approached by studying individual differences in "pro-stress" mediators such as corticosteroids or the hypothalamic orchestrator of the stress response, corticotropin-releasing factor. More recently, the recognition of endogenous neuromodulators with "anti-stress" activity that have opposing actions or that restrain stress-response systems suggests additional bases for individual differences in stress pathology. These "anti-stress" neuromodulators offer alternative strategies for manipulating the stress response and its pathological consequences. This review uses the major brain norepinephrine system as a model stress-response system to demonstrate how co-regulation by opposing pro-stress (corticotropin-releasing factor) and anti-stress (enkephalin) neuromodulators must be fine-tuned to produce an adaptive response to stress. The clinical consequences of tipping this fine-tuned balance in the direction of either the pro- or anti-stress systems are emphasized. Finally, that each system provides multiple points at which individual differences could confer stress vulnerability or resilience is discussed.
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Affiliation(s)
- Rita J. Valentino
- Department of Anesthesia and Critical Care Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
- University of Pennsylvania, Philadelphia, PA 19104, USA
- Corresponding author. Department of Anesthesia and Critical Care Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
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11
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Knockdown of CRF1 receptors in the ventral tegmental area attenuates cue- and acute food deprivation stress-induced cocaine seeking in mice. J Neurosci 2014; 34:11560-70. [PMID: 25164654 DOI: 10.1523/jneurosci.4763-12.2014] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Corticotrophin-releasing factor (CRF) modulates the influence of stress on cocaine reward and reward seeking acting at multiple sites, including the ventral tegmental area (VTA). There is controversy, however, concerning the contribution of CRF receptor type 1 (CRFR1) to this effect and whether CRF within the VTA is involved in other aspects of reward seeking independent of acute stress. Here we examine the role of CRFR1 within the VTA in relation to cocaine and natural reward using viral delivery of short hairpin RNAs (lenti-shCRFR1) and investigate the effect on operant self-administration and motivation to self-administer, as well as stress- and cue-induced reward seeking in mice. While knockdown of CRFR1 in the VTA had no effect on self-administration behavior for either cocaine or sucrose, it effectively blocked acute food deprivation stress-induced reinstatement of cocaine seeking. We also observed reduced cue-induced cocaine seeking assessed in a single extinction session after extended abstinence, but cue-induced sucrose seeking was unaffected, suggesting dissociation between the contribution of CRFR1 in the VTA in cocaine reward and sucrose and cocaine seeking. Further, our data indicate a role for VTA CRFR1 signaling in cocaine seeking associated with, and independent of, stress potentially involving conditioning and/or salience attribution of cocaine reward-related cues. CRFR1 signaling in the VTA therefore presents a target for convergent effects of both cue- and stress-induced cocaine-seeking pathways.
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12
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Schilling JM, Cui W, Godoy JC, Risbrough VB, Niesman IR, Roth DM, Patel PM, Drummond JC, Patel HH, Zemljic-Harpf AE, Head BP. Long-term atorvastatin treatment leads to alterations in behavior, cognition, and hippocampal biochemistry. Behav Brain Res 2014; 267:6-11. [PMID: 24657594 PMCID: PMC4059187 DOI: 10.1016/j.bbr.2014.03.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 03/07/2014] [Accepted: 03/12/2014] [Indexed: 11/28/2022]
Abstract
Membrane/lipid rafts (MLR) are plasmalemmal microdomains that are essential for neuronal signaling and synaptic development/stabilization. Statins inhibit HMG-CoA reductase, the rate-limiting enzyme in the biosynthesis of mevalonic, a precursor to cholesterol via the mevalonate pathway. Because there has been controversy over the effects of statins on neuronal and cognitive function, we investigated the impact of long-term atorvastatin treatment (5mg/kg/d for 7 months by oral gavage) on behavior, cognition, and brain biochemistry in mice. We hypothesized that long-term statin treatment would alter lipid rafts and cognitive function. Atorvastatin treatment resulted in behavioral deficits as measured in paradigms for basic exploration (open field activity) and cognitive function (Barnes maze, startle response) without impairment in global motor function (Rotor Rod). Furthermore, significant changes in MLR-associated proteins (syntaxin-1α and synaptophysin) and a global change of post-synaptic density protein-95 (PSD95) were observed. The observed decreases in the MLR-localized pre-synaptic vesicle proteins syntaxin-1α and synaptophysin suggest a molecular mechanism for the statin-associated impairment of cognitive function that was observed and that has been suggested by the clinical literature.
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Affiliation(s)
- Jan M Schilling
- VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA; Department of Anesthesiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Weihua Cui
- Department of Anesthesiology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China; VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA; Department of Anesthesiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Joseph C Godoy
- VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA; Department of Anesthesiology, University of California, San Diego, La Jolla, CA 92093, USA; Department of Anesthesiology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China; Department of Psychiatry, University of California, San Diego, La Jolla, CA 92092, USA
| | - Victoria B Risbrough
- VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA; Department of Psychiatry, University of California, San Diego, La Jolla, CA 92092, USA
| | - Ingrid R Niesman
- Department of Anesthesiology, University of California, San Diego, La Jolla, CA 92093, USA; VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA
| | - David M Roth
- VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA; Department of Anesthesiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Piyush M Patel
- VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA; Department of Anesthesiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - John C Drummond
- VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA; Department of Anesthesiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Hemal H Patel
- VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA; Department of Anesthesiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Alice E Zemljic-Harpf
- VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA; Department of Anesthesiology, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Brian P Head
- VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA; Department of Anesthesiology, University of California, San Diego, La Jolla, CA 92093, USA.
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13
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Callahan LB, Tschetter KE, Ronan PJ. Inhibition of corticotropin releasing factor expression in the central nucleus of the amygdala attenuates stress-induced behavioral and endocrine responses. Front Neurosci 2013; 7:195. [PMID: 24194694 PMCID: PMC3810776 DOI: 10.3389/fnins.2013.00195] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 10/08/2013] [Indexed: 11/13/2022] Open
Abstract
Corticotropin releasing factor (CRF) is a primary mediator of endocrine, autonomic and behavioral stress responses. Studies in both humans and animal models have implicated CRF in a wide-variety of psychiatric conditions including anxiety disorders such as post-traumatic stress disorder (PTSD), depression, sleep disorders and addiction among others. The central nucleus of the amygdala (CeA), a key limbic structure with one of the highest concentrations of CRF-producing cells outside of the hypothalamus, has been implicated in anxiety-like behavior and a number of stress-induced disorders. This study investigated the specific role of CRF in the CeA on both endocrine and behavioral responses to stress. We used RNA Interference (RNAi) techniques to locally and specifically knockdown CRF expression in CeA. Behavior was assessed using the elevated plus maze (EPM) and open field test (OF). Knocking down CRF expression in the CeA had no significant effect on measures of anxiety-like behavior in these tests. However, it did have an effect on grooming behavior, a CRF-induced behavior. Prior exposure to a stressor sensitized an amygdalar CRF effect on stress-induced HPA activation. In these stress-challenged animals silencing CRF in the CeA significantly attenuated corticosterone responses to a subsequent behavioral stressor. Thus, it appears that while CRF projecting from the CeA does not play a significant role in the expression stress-induced anxiety-like behaviors on the EPM and OF it does play a critical role in stress-induced HPA activation.
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Affiliation(s)
- Leah B Callahan
- Avera Research Institute, Avera McKennan Hospital and University Health Center Sioux Falls, SD, USA ; Neuroscience Group, Division of Basic Biomedical Sciences, University of South Dakota Sanford School of Medicine Vermillion, SD, USA ; Department of Psychiatry, University of South Dakota Sanford School of Medicine Sioux Falls, SD, USA ; Research Service, Sioux Falls VA Health Care System Sioux Falls, SD, USA
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14
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M T, JE G, RL H, AL H, VB R. The role of PKC signaling in CRF-induced modulation of startle. Psychopharmacology (Berl) 2013; 229:579-89. [PMID: 23722830 PMCID: PMC3784645 DOI: 10.1007/s00213-013-3114-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 04/11/2013] [Indexed: 02/06/2023]
Abstract
RATIONALE Hypersignaling of corticotropin releasing factor (CRF) has been implicated in stress disorders; however, many of its downstream mechanisms of action remain unclear. In vitro, CRF1 receptor activation initiates multiple cell signaling cascades, including protein kinase A (PKA), protein kinase C (PKC), and mitogen-activated protein kinase kinase MEK1/2 signaling. It is unclear, however, which of these signaling cascades mediate CRF-induced behaviors during stress. OBJECTIVES We examined the role of PKA, PKC, and MEK1/2 signaling pathways in CRF-induced anxiety as measured by startle hyperreactivity. METHODS Mice treated with intracerbroventricular (ICV) ovine CRF (oCRF) were pretreated with the PKA inhibitor Rp-cAMPS, PKC inhibitor bisindolylmaleimide (BIM), or MEK1/2 inhibitor PD98059 (ICV) and assessed for acoustic startle reactivity. RESULTS The PKC inhibitor BIM significantly attenuated CRF-induced increases in startle. BIM was also able to block startle increases induced by oCRF when both compounds were infused directly into the bed nucleus of stria terminalis (BNST). PKA and MEK1/2 inhibition had no significant effects on CRF-induced changes in startle at the dose ranges tested. CRF-induced disruption of prepulse inhibition was not significantly reversed by any of the three pretreatments at the dose ranges tested. CONCLUSIONS PKC signaling is required for CRF-induced increases in startle, and this effect is mediated at least in part at the BNST. These findings suggest that PKC signaling cascades (1) may be important for the acute effects of CRF to induce startle hyperreactivity and (2) support further research of the role of PKC signaling in startle abnormalities relevant to disorders such as posttraumatic stress disorder.
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Affiliation(s)
- Toth M
- Center of Excellence for Stress and Mental Health, Veterans Affairs Hospital, La Jolla CA USA,Dept. of Psychiatry, University of California San Diego, La Jolla CA USA
| | - Gresack JE
- Center of Excellence for Stress and Mental Health, Veterans Affairs Hospital, La Jolla CA USA,Dept. of Psychiatry, University of California San Diego, La Jolla CA USA,Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York NY USA
| | - Hauger RL
- Center of Excellence for Stress and Mental Health, Veterans Affairs Hospital, La Jolla CA USA,Dept. of Psychiatry, University of California San Diego, La Jolla CA USA
| | - Halberstadt AL
- Dept. of Psychiatry, University of California San Diego, La Jolla CA USA
| | - Risbrough VB
- Center of Excellence for Stress and Mental Health, Veterans Affairs Hospital, La Jolla CA USA,Dept. of Psychiatry, University of California San Diego, La Jolla CA USA,Corresponding author: Victoria Risbrough, Ph.D., University of California San Diego, 9500 Gilman Dr. MC0804, La Jolla CA 92093-0804, Tel: 16195433582; Fax: 16195432475:
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15
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Hauger RL, Olivares-Reyes JA, Braun S, Hernandez-Aranda J, Hudson CC, Gutknecht E, Dautzenberg FM, Oakley RH. Desensitization of human CRF2(a) receptor signaling governed by agonist potency and βarrestin2 recruitment. ACTA ACUST UNITED AC 2013; 186:62-76. [PMID: 23820308 DOI: 10.1016/j.regpep.2013.06.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 04/18/2013] [Accepted: 06/20/2013] [Indexed: 01/04/2023]
Abstract
The primary goal was to determine agonist-specific regulation of CRF2(a) receptor function. Exposure of human retinoblastoma Y79 cells to selective (UCN2, UCN3 or stresscopins) and non-selective (UCN1 or sauvagine) agonists prominently desensitized CRF2(a) receptors in a rapid, concentration-dependent manner. A considerably slower rate and smaller magnitude of desensitization developed in response to the weak agonist CRF. CRF1 receptor desensitization stimulated by CRF, cortagine or stressin1-A had no effect on CRF2(a) receptor cyclic AMP signaling. Conversely, desensitization of CRF2(a) receptors by UCN2 or UCN3 did not cross-desensitize Gs-coupled CRF1 receptor signaling. In transfected HEK293 cells, activation of CRF2(a) receptors by UCN2, UCN3 or CRF resulted in receptor phosphorylation and internalization proportional to agonist potency. Neither protein kinase A nor casein kinases mediated CRF2(a) receptor phosphorylation or desensitization. Exposure of HEK293 or U2OS cells to UCN2 or UCN3 (100nM) produced strong βarrestin2 translocation and colocalization with membrane CRF2(a) receptors while CRF (1μM) generated only weak βarrestin2 recruitment. βarrestin2 did not internalize with the receptor, however, indicating that transient CRF2(a) receptor-arrestin complexes dissociate at or near the cell membrane. Since deletion of the βarrestin2 gene upregulated Gs-coupled CRF2(a) receptor signaling in MEF cells, a βarrestin2 mechanism restrains Gs-coupled CRF2(a) receptor signaling activated by urocortins. We further conclude that the rate and extent of homologous CRF2(a) receptor desensitization are governed by agonist-specific mechanisms affecting GRK phosphorylation, βarrestin2 recruitment, and internalization thereby producing unique signal transduction profiles that differentially affect the stress response.
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Affiliation(s)
- Richard L Hauger
- Center of Excellence for Stress and Mental Health, San Diego VA Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA; Department of Psychiatry, School of Medicine, University of California, 9500 Gilman Drive, La Jolla, San Diego, CA 92093, USA.
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16
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Abstract
Norepinephrine and epinephrine signaling is thought to facilitate cognitive processes related to emotional events and heightened arousal; however, the specific role of epinephrine in these processes is less known. To investigate the selective impact of epinephrine on arousal and fear-related memory retrieval, mice unable to synthesize epinephrine (phenylethanolamine N-methyltransferase knockout, PNMT-KO) were tested for contextual and cued-fear conditioning. To assess the role of epinephrine in other cognitive and arousal-based behaviors these mice were also tested for acoustic startle, prepulse inhibition, novel object recognition, and open-field activity. Our results show that compared with wild-type mice, PNMT-KO mice showed reduced contextual fear but normal cued fear. Mice exhibited normal memory performance in the short-term version of the novel object recognition task, suggesting that PNMT mice exhibit more selective memory effects on highly emotional and/or long-term memories. Similarly, open-field activity was unaffected by epinephrine deficiency, suggesting that differences in freezing are not related to changes in overall anxiety or exploratory drive. Startle reactivity to acoustic pulses was reduced in PNMT-KO mice, whereas prepulse inhibition was increased. These findings provide further evidence for a selective role of epinephrine in contextual-fear learning and support its potential role in acoustic startle.
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17
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Human fear acquisition deficits in relation to genetic variants of the corticotropin releasing hormone receptor 1 and the serotonin transporter. PLoS One 2013; 8:e63772. [PMID: 23717480 PMCID: PMC3661730 DOI: 10.1371/journal.pone.0063772] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 04/08/2013] [Indexed: 12/16/2022] Open
Abstract
The ability to identify predictors of aversive events allows organisms to appropriately respond to these events, and failure to acquire these fear contingencies can lead to maladaptive contextual anxiety. Recently, preclinical studies demonstrated that the corticotropin-releasing factor and serotonin systems are interactively involved in adaptive fear acquisition. Here, 150 healthy medication-free human subjects completed a cue and context fear conditioning procedure in a virtual reality environment. Fear potentiation of the eyeblink startle reflex (FPS) was measured to assess both uninstructed fear acquisition and instructed fear expression. All participants were genotyped for polymorphisms located within regulatory regions of the corticotropin releasing hormone receptor 1 (CRHR1 - rs878886) and the serotonin transporter (5HTTLPR). These polymorphisms have previously been linked to panic disorder and anxious symptomology and personality, respectively. G-allele carriers of CRHR1 (rs878886) showed no acquisition of fear conditioned responses (FPS) to the threat cue in the uninstructed phase, whereas fear acquisition was present in C/C homozygotes. Moreover, carrying the risk alleles of both rs878886 (G-allele) and 5HTTLPR (short allele) was associated with increased FPS to the threat context during this phase. After explicit instructions regarding the threat contingency were given, the cue FPS and context FPS normalized in all genotype groups. The present results indicate that genetic variability in the corticotropin-releasing hormone receptor 1, especially in interaction with the 5HTTLPR, is involved in the acquisition of fear in humans. This translates prior animal findings to the human realm.
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18
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Hoffman KL. Role of murine models in psychiatric illness drug discovery: a dimensional view. Expert Opin Drug Discov 2013; 8:865-77. [DOI: 10.1517/17460441.2013.797959] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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19
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Borelli KG, Albrechet-Souza L, Fedoce AG, Fabri DS, Resstel LB, Brandão ML. Conditioned fear is modulated by CRF mechanisms in the periaqueductal gray columns. Horm Behav 2013; 63:791-9. [PMID: 23603480 DOI: 10.1016/j.yhbeh.2013.04.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 04/05/2013] [Accepted: 04/10/2013] [Indexed: 12/27/2022]
Abstract
The periaqueductal gray (PAG) columns have been implicated in controlling stress responses through corticotropin-releasing factor (CRF), which is a neuropeptide with a prominent role in the etiology of fear- and anxiety-related psychopathologies. Several studies have investigated the involvement of dorsal PAG (dPAG) CRF mechanisms in models of unconditioned fear. However, less is known about the role of this neurotransmission in the expression of conditioned fear memories in the dPAG and ventrolateral PAG (vlPAG) columns. We assessed the effects of ovine CRF (oCRF 0.25 and 1.0 μg/0.2 μL) locally administered into the dPAG and vlPAG on behavioral (fear-potentiated startle and freezing) and autonomic (arterial pressure and heart rate) responses in rats subjected to contextual fear conditioning. The lower dose injected into the columns promoted proaversive effects, enhanced contextual freezing, increased the blood pressure and heart rate and decreased tail temperature. The lower dose of oCRF into the vlPAG, but not into the dPAG, produced a pronounced enhancement of the fear-potentiated startle response. The results imply that the PAG is a heterogeneous structure that is involved in the coordination of distinct behaviors and autonomic control, suggest PAG involvement in the expression of contextual fear memory as well as implicate the CRF as an important modulator of the neural substrates of fear in the PAG.
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Affiliation(s)
- Karina G Borelli
- Instituto de Neurociências e Comportamento, Ribeirão Preto, SP, Brazil.
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20
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Effects of continuously enhanced corticotropin releasing factor expression within the bed nucleus of the stria terminalis on conditioned and unconditioned anxiety. Mol Psychiatry 2013; 18:308-19. [PMID: 22290119 PMCID: PMC3578178 DOI: 10.1038/mp.2011.188] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The lateral division of the bed nucleus of the stria terminalis (BNST), which forms part of the circuitry regulating fear and anxiety, contains a large number of neurons expressing corticotropin releasing factor (CRF), a neuropeptide that has a prominent role in the etiology of fear- and anxiety-related psychopathologies. Stress increases CRF expression within BNST neurons, implicating these cells in stress- and anxiety-related behaviors. These experiments examined the effect of chronically enhanced CRF expression within BNST neurons on conditioned and unconditioned anxiety-related behavior by using a lentiviral vector containing a promoter that targets CRF gene overexpression (OE) to CRFergic cells. We found that BNST CRF-OE did not affect unconditioned anxiety-like responses in the elevated plus maze or basal acoustic startle amplitude. CRF-OE induced before training weakened sustained fear (conditioned anxiety); when induced after conditioning, CRF-OE increased expression of the conditioned emotional memory. Increased BNST CRF expression did not affect plasma corticosterone concentration but did decrease CRFR1 receptor density within the BNST and CRFR2 receptor density within the dorsal portion of the caudal dorsal raphe nucleus. These data raise the possibility that the observed behavioral effects may be mediated by enhanced CRF receptor signaling or compensatory changes in CRF receptor density within these structures. Together, these studies demonstrate that CRF neurons within the lateral BNST modulate conditioned anxiety-like behaviors and also suggest that enhanced CRF expression within these neurons may contribute to inappropriate regulation of emotional memories.
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21
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Susceptibility to PTSD-like behavior is mediated by corticotropin-releasing factor receptor type 2 levels in the bed nucleus of the stria terminalis. J Neurosci 2012; 32:6906-16. [PMID: 22593059 DOI: 10.1523/jneurosci.4012-11.2012] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Posttraumatic stress disorder (PTSD) is a debilitating disease, which affects 8-10% of the population exposed to traumatic events. The factors that make certain individuals susceptible to PTSD and others resilient are currently unknown. Corticotropin-releasing factor receptor type 2 (CRFR2) has been implicated in mediating stress coping mechanisms. Here, we use a physiological PTSD-like animal model and an in-depth battery of tests that reflect the symptomology of PTSD to separate mice into subpopulations of "PTSD-like" and "Resilient" phenotypes. PTSD-like mice are hypervigilant, hyperalert, insomniac, have impaired attention and risk assessment, as well as accompanying attenuated corticosterone levels. Intriguingly, PTSD-like mice show long-term robust upregulation of BNST-CRFR2 mRNA levels, and BNST-CRFR2-specific lentiviral knockdown reduces susceptibility to PTSD-like behavior. Additionally, using a BNST mRNA expression array, PTSD-like mice exhibit a general transcriptional attenuation profile, which was associated with upregulation of the BNST-deacetylation enzyme, HDAC5. We suggest PTSD to be a disease of maladaptive coping.
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22
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Devetzis V, Zarogoulidis P, Kakolyris S, Vargemezis V, Chatzaki E. The corticotropin releasing factor system in the kidney: perspectives for novel therapeutic intervention in nephrology. Med Res Rev 2012; 33:847-72. [PMID: 22622997 DOI: 10.1002/med.21268] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The adaptation to endogenous and exogenous stress stimuli is crucial for survival but also for the onset of various diseases in humans. Corticotropin releasing factor (CRF) system is the major regulator of stress response and homeostasis. The members of this family of peptides extend their actions also outside CNS to the periphery where they may affect various body systems independently, acting via vagal and/or autocrine/paracrine pathways. In search for peripheral targets, kidney has rarely been studied separately, regarding expression and action of CRF and CRF-related peptides. We reviewed the existing literature concerning expression and action of the CRF system in normal and pathological renal tissue and explored possible clinical implications in nephrology. CRF system components are expressed in the kidney of experimental animals and in humans. The intrarenal distribution is reported to be equally extensive, suggesting a physiological or pathophysiological role in renal function and in the occurrence of renal disease. Urocortins have given multiple interesting observations in experimental models of renal disease and clinical studies, showing robust effects in renal regulation mechanisms. We summarize the relevant data and put them in context, proposing applications with clinical significance in the field of hypertension, diabetic nephropathy, chronic kidney disease, cardiorenal syndrome, and peritoneal dialysis.
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Affiliation(s)
- Vassilis Devetzis
- Laboratory of Pharmacology, Faculty of Medicine, Democritus University of Thrace, Alexandroupolis, Greece
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23
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Hauger RL, Olivares-Reyes JA, Dautzenberg FM, Lohr JB, Braun S, Oakley RH. Molecular and cell signaling targets for PTSD pathophysiology and pharmacotherapy. Neuropharmacology 2011; 62:705-14. [PMID: 22122881 DOI: 10.1016/j.neuropharm.2011.11.007] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2011] [Revised: 11/01/2011] [Accepted: 11/14/2011] [Indexed: 12/20/2022]
Abstract
The reasons for differences in vulnerability or resilience to the development of posttraumatic stress disorder (PTSD) are unclear. Here we review key genetic diatheses and molecular targets especially signaling pathways that mediate responses to trauma and severe stress and their potential contribution to the etiology of PTSD. Sensitization of glucocorticoid receptor (GR) signaling and dysregulation of GR modulators FKBP5, STAT5B, Bcl-2, and Bax have been implicated in PTSD pathophysiology. Furthermore, Akt, NFκB, MKP-1, and p11, which are G protein-coupled receptor (GPCR) pathway molecules, can promote or prevent sustained high anxiety- and depressive-like behavior following severe stress. Agonist-induced activation of the corticotropin releasing factor CRF(1) receptor is crucial for survival in the context of serious danger or trauma, but persistent CRF(1) receptor hypersignaling when a threatening or traumatic situation is no longer present is maladaptive. CRF(1) receptor single nucleotide polymorphisms (SNPs) can confer susceptibility or resilience to childhood trauma while a SNP for the PAC1 receptor, another class B1 GPCR, has been linked genetically to PTSD. GRK3 phosphorylation of the CRF(1) receptor protein and subsequent binding of βarrestin2 rapidly terminate Gs-coupled CRF(1) receptor signaling by homologous desensitization. A deficient GRK-βarrestin2 mechanism would result in excessive CRF(1) receptor signaling thereby contributing to PTSD and co-morbid posttraumatic depression. Clinical trials are needed to assess if small molecule CRF(1) receptor antagonists are effective prophylactic agents when administered immediately after trauma. βarrestin2-biased agonists for CRF receptors and possibly other GPCRs implicated in PTSD, however, may prove to be novel pharmacotherapy with greater selectivity and therapeutic efficacy. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.
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Affiliation(s)
- Richard L Hauger
- Center of Excellence for Stress and Mental Health, VA Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA.
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Boyson CO, Miguel TT, Quadros IM, Debold JF, Miczek KA. Prevention of social stress-escalated cocaine self-administration by CRF-R1 antagonist in the rat VTA. Psychopharmacology (Berl) 2011; 218:257-69. [PMID: 21468623 PMCID: PMC3166547 DOI: 10.1007/s00213-011-2266-8] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Accepted: 03/11/2011] [Indexed: 01/22/2023]
Abstract
RATIONALE Intermittent exposure to social defeat stress can induce long-term neural plasticity that may influence escalated cocaine-taking behavior. Stressful encounters can lead to activation of dopamine neurons in the ventral tegmental area (VTA), which are modulated by corticotropin releasing factor (CRF) neurons. OBJECTIVE The study aims to prevent the effects of intermittently scheduled, brief social defeat stress on subsequent intravenous (IV) cocaine self-administration by pretreatment with a CRF receptor subtype 1 (CRF-R1) antagonist. MATERIALS AND METHODS Long-Evans rats were submitted to four intermittent social defeat experiences separated by 72 h over 10 days. Two experiments examined systemic or intra-VTA antagonism of CRF-R1 subtype during stress on the later expression of locomotor sensitization and cocaine self-administration during fixed (0.75 mg/kg/infusion) and progressive ratio schedules of reinforcement (0.3 mg/kg/infusion), including a continuous 24-h "binge" (0.3 mg/kg/infusion). RESULTS Pretreatment with a CRF-R1 antagonist, CP 154,526, (20 mg/kg i.p.) prior to each social defeat episode prevented the development of stress-induced locomotor sensitization to a cocaine challenge and prevented escalated cocaine self-administration during a 24-h "binge". In addition, pretreatment with a CRF-R1 antagonist (0.3 μg/0.5 μl/side) into the VTA prior to each social defeat episode prevented stress-induced locomotor sensitization to a cocaine challenge and prevented escalated cocaine self-administration during a 24-h "binge". CONCLUSIONS The current results suggest that CRF-R1 subtype in the VTA is critically involved in the development of stress-induced locomotor sensitization which may contribute to escalated cocaine self-administration during continuous access in a 24-h "binge".
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Corticotropin-releasing factor and noradrenergic signalling exert reciprocal control over startle reactivity. Int J Neuropsychopharmacol 2011; 14:1179-94. [PMID: 21205416 PMCID: PMC3601827 DOI: 10.1017/s1461145710001409] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Corticotropin-releasing factor (CRF) and norepinephrine (NE) levels are altered in post-traumatic stress disorder and may be related to symptoms of hyperarousal, including exaggerated startle, in these patients. In animals, activation of both systems modulates anxiety behaviours including startle plasticity; however, it is unknown if they exert their actions orthogonally or dependently. We tested the hypothesis that NE receptor activation is required for CRF effects on startle and that CRF1 receptor activation is required for NE effects on startle. The study examined the effects of: (1) α2 agonist clonidine (0.18 mg/kg i.p.), α1 antagonist prazosin (0.8 mg/kg), and β1/2 antagonist propranolol (0.8, 8.0 mg/kg) pretreatment on ovine-CRF (oCRF)- (0.6 nmol) induced increases in startle reactivity and disruption of prepulse inhibition (PPI); (2) α2 antagonist atipamezole (1-30 mg/kg) and α1 agonist cirazoline (0.025-1.0 mg/kg) treatment on startle; (3) CRF1 antagonist (antalarmin, 14 mg/kg) pretreatment on atipamezole- (10.0 mg/kg) induced increases in startle. oCRF robustly increased startle and reduced PPI. Pretreatment with clonidine or prazosin, but not propranolol, blocked oCRF-induced increases in startle but had no effect on oCRF-induced disruptions in PPI. Atipamezole treatment increased startle, which was partially attenuated by CRF1 antagonist pretreatment. Cirazoline treatment did not increase startle. These findings suggest that CRF modulation of startle, but not PPI, requires activation of α1 adrenergic receptors, while CRF1 activation also contributes to NE modulation of startle. These data support a bi-directional model of CRF-NE modulation of stress responses and suggest that both systems must be activated to induce stress effects on startle reactivity.
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Schulkin J. Evolutionary conservation of glucocorticoids and corticotropin releasing hormone: Behavioral and physiological adaptations. Brain Res 2011; 1392:27-46. [DOI: 10.1016/j.brainres.2011.03.055] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2009] [Revised: 03/14/2011] [Accepted: 03/22/2011] [Indexed: 02/05/2023]
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Skórzewska A, Lehner M, Hamed A, Wisłowska-Stanek A, Turzyńska D, Sobolewska A, Płaźnik A. The effect of CRF2 receptor antagonists on rat conditioned fear responses and c-Fos and CRF expression in the brain limbic structures. Behav Brain Res 2011; 221:155-65. [PMID: 21376756 DOI: 10.1016/j.bbr.2011.02.036] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 02/15/2011] [Accepted: 02/24/2011] [Indexed: 12/11/2022]
Abstract
The influence of intracerebroventricular-administered selective corticotropin-releasing factor receptor 2 (CRF(2)) antagonists (antisauvagine-30, astressin-2B), on rat anxiety-like behavior, expression levels of c-Fos and CRF, and plasma corticosterone levels were examined in the present study. In fear-conditioned animals, both CRF receptor antagonists enhanced a conditioned freezing fear response and increased the conditioned fear-elevated concentration of serum corticosterone. Exogenously administered antisauvagine-30 increased the aversive context-induced expression of c-Fos in the 1 and 2 areas of the cingulate cortex (Cg1, Cg2), the central amygdala (CeA) and parvocellular neurons of the paraventricular hypothalamic nucleus (pPVN), and it enhanced the effect of conditioned fear in the secondary motor cortex (M2) and medial amygdala (MeA). Immunocytochemistry demonstrated an increase in CRF expression in the Cg1, M2 areas of the cortex, and pPVN, and it revealed the effect of conditioned fear in the CeA 35 min after antisauvagine-30 administration and 10 min after the conditioned fear test. Furthermore, astressin-2B, another CRF(2) receptor antagonist, enhanced expression of c-Fos and CRF in the CeA and pPVN, and revealed the effect of conditioned fear in the Cg1. These data support a model in which an excess in CRF(1) receptor activation, combined with reduced CRF(2) receptor signaling, may contribute to stronger expression of anxiety-like responses.
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Affiliation(s)
- A Skórzewska
- Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957 Warsaw, Poland.
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Skórzewska A, Bidziński A, Lehner M, Turzyńska D, Sobolewska A, Wisłowska-Stanek A, Maciejak P, Szyndler J, Płaźnik A. The localization of brain sites of anxiogenic-like effects of urocortin-2. Neuropeptides 2011; 45:83-92. [PMID: 21168912 DOI: 10.1016/j.npep.2010.11.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 11/24/2010] [Accepted: 11/24/2010] [Indexed: 01/02/2023]
Abstract
The influence of intracerebroventricullary-administered urocortin-2, a selective corticotropin-releasing factor receptor 2 (CRF(2)) agonist, on rat anxiety-like behaviour, the expression of c-Fos and CRF, and plasma corticosterone levels was examined in the present study. When applied to animals exposed to the conditioned fear-induced context, urocortin-2 enhanced a conditioned freezing fear response. Urocortin-2 also significantly decreased rat exploratory activity in the open field test. Exogenous urocortin-2 increased the conditioned fear-induced expression of c-Fos in the central amygdala (CeA), and parvocellular neurons of the paraventricular hypothalamic nucleus (pPVN), and revealed the effect of conditioned fear in the medial amygdala (MeA). In the fear-conditioned animals, immunocytochemistry showed an increase in the density of CRF-related immunoreactive complexes in the lateral septum (LS), 35min after urocortin-2 administration and 10min after the conditioned fear test, compared with saline-pretreated fear-conditioned animals. These data suggest a role of urocortin-2 in the behavioural and immunocytochemical responses to stress, in which it strengthens the measures of anxiety-like responses.
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Affiliation(s)
- A Skórzewska
- Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957 Warsaw, Poland.
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Smith KS, Meloni EG, Myers KM, Van't Veer A, Carlezon WA, Rudolph U. Reduction of fear-potentiated startle by benzodiazepines in C57BL/6J mice. Psychopharmacology (Berl) 2011; 213:697-706. [PMID: 20922362 PMCID: PMC3056161 DOI: 10.1007/s00213-010-2026-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Accepted: 09/15/2010] [Indexed: 11/24/2022]
Abstract
RATIONALE Anxiety disorders affect 18% of the United States adult population annually. Recent surges in the diagnosis of posttraumatic stress disorder (PTSD) from combat-exposed veterans have prompted an urgent need to understand the pathophysiology underlying this debilitating condition. OBJECTIVES Anxiety and fear responses are partly modulated by gamma aminobutyric acid type A (GABA(A)) receptor-mediated synaptic inhibition; benzodiazepines potentiate GABAergic inhibition and are effective anxiolytics. Many genetically modified mouse lines are generated and/or maintained on the C57BL/6J background, a strain where manipulation of anxiety-like behavior using benzodiazepines is difficult. Fear-potentiated startle (FPS), a test of conditioned fear, is a useful preclinical tool to study PTSD-like responses but has been difficult to establish in C57BL/6J mice. METHODS We modified several FPS experimental parameters and developed a paradigm to assess conditioned fear in C57BL/6J mice. The 6-day protocol consisted of three startle Acclimation days, a Pre-Test day followed by Training and Testing for FPS. Subject responses to the effects of three benzodiazepines were also examined. RESULTS C57BL/6J mice had low levels of unconditioned fear assessed during Pre-Test (15-18%) but showed robust FPS (80-120%) during the Test session. Conditioned fear responses extinguished over repeated test sessions. Administration of the benzodiazepines alprazolam (0.5 and 1 mg/kg, i.p.), chlordiazepoxide (5 and 10 mg/kg, i.p.), and diazepam (1, 2, and 4 mg/kg, i.p.) significantly reduced FPS to Pre-Test levels. CONCLUSIONS We used a modified and pharmacologically-validated paradigm to assess FPS in mice thereby providing a powerful tool to examine the neurobiology of PTSD in genetic models of anxiety generated on the C57BL/6J background.
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Affiliation(s)
- Kiersten S Smith
- Department of Psychiatry, McLean Hospital and Harvard Medical School, 115 Mill Street, Belmont, MA 02478, USA.
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Serotonin1A receptor deletion does not interact with maternal separation-induced increases in startle reactivity and prepulse inhibition deficits. Psychopharmacology (Berl) 2011; 214:353-65. [PMID: 20811879 PMCID: PMC3045511 DOI: 10.1007/s00213-010-1998-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2010] [Accepted: 08/10/2010] [Indexed: 02/01/2023]
Abstract
RATIONALE Early life stress is a risk factor for the development of psychopathology in later life. Consequences of adverse life events, however, may depend on the genetic makeup of an individual. Reduced serotonin(1A) receptor function may predispose to the development of anxiety disorders. OBJECTIVE Determine susceptibility of serotonin(1A) receptor knockout (1AKO) mice on different background strains to the effects of maternal separation (MS) by assessing startle plasticity in adulthood. METHODS 1AKO mice on a 129S6 and a Swiss Webster (SW) background were used. MS groups were separated daily from their mother for 180 min/day from postnatal days 2 to 14. Control groups underwent normal animal facility rearing. In adulthood, effects on acoustic startle response, habituation, prepulse inhibition (PPI), and foot shock sensitization were determined. RESULTS MS increased startle reactivity and reduced PPI in 129S6 mice. These effects of MS were independent of genotype. MS had no effect on the other readouts. In SW mice, MS had no consistent effect on startle reactivity and did not alter startle plasticity in wild type or in 1AKO mice. 1AKO mice did not differ from wild-type mice in startle plasticity. CONCLUSION Serotonin(1A) receptor deletion does not enhance vulnerability to the effects of MS on startle plasticity. The life-long increase in startle reactivity and PPI deficit induced by MS are strain-dependent. Further, the use of startle reactivity and plasticity may have added value in translational studies relating to early life stress.
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Ronan PJ, Summers CH. Molecular Signaling and Translational Significance of the Corticotropin Releasing Factor System. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 98:235-92. [DOI: 10.1016/b978-0-12-385506-0.00006-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Missig G, Ayers LW, Schulkin J, Rosen JB. Oxytocin reduces background anxiety in a fear-potentiated startle paradigm. Neuropsychopharmacology 2010; 35:2607-16. [PMID: 20844476 PMCID: PMC3055566 DOI: 10.1038/npp.2010.155] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Revised: 08/08/2010] [Accepted: 08/09/2010] [Indexed: 12/20/2022]
Abstract
Oxytocin reportedly decreases anxious feelings in humans and may therefore have therapeutic value for anxiety disorders, such as post-traumatic stress disorder (PTSD). As PTSD patients have exaggerated startle responses, a fear-potentiated startle paradigm in rats may have face validity as an animal model to examine the efficacy of oxytocin in treating these symptoms. Oxytocin (0, 0.01, 0.1, or 1.0 μg, subcutaneously) was given either 30 min before fear conditioning, immediately after fear conditioning, or 30 min before fear-potentiated startle testing to assess its effects on acquisition, consolidation, and expression of conditioned fear, respectively. Startle both in the presence and absence of the fear-conditioned light was significantly diminished by oxytocin when administered at acquisition, consolidation, or expression. There was no specific effect of oxytocin on light fear-potentiated startle. In an additional experiment, oxytocin had no effects on acoustic startle without previous fear conditioning. Further, in a context-conditioned test, previous light-shock fear conditioning did not increase acoustic startle during testing when the fear-conditioned light was not presented. The data suggest that oxytocin did not diminish cue-specific conditioned nor contextually conditioned fear, but reduced background anxiety. This suggests that oxytocin has unique effects of decreasing background anxiety without affecting learning and memory of a specific traumatic event. Oxytocin may have antianxiety properties that are particularly germane to the hyper-vigilance and exaggerated startle typically seen in PTSD patients.
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Affiliation(s)
- Galen Missig
- Department of Psychology, Behavioral Neuroscience Program, University of Delaware, Newark, DE, USA
| | - Luke W Ayers
- Department of Psychology, Behavioral Neuroscience Program, University of Delaware, Newark, DE, USA
| | - Jay Schulkin
- Department of Neuroscience, Georgetown University, Washington, DC, USA; Behavioral Endocrinology Section, National Institute of Mental Health, Bethesda, MD, USA; Research Department, American College of Obstetricians and Gynecologists, Washington, DC, USA
| | - Jeffrey B Rosen
- Department of Psychology, Behavioral Neuroscience Program, University of Delaware, Newark, DE, USA
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Kehne JH, Cain CK. Therapeutic utility of non-peptidic CRF1 receptor antagonists in anxiety, depression, and stress-related disorders: evidence from animal models. Pharmacol Ther 2010; 128:460-87. [PMID: 20826181 DOI: 10.1016/j.pharmthera.2010.08.011] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2010] [Accepted: 08/17/2010] [Indexed: 12/19/2022]
Abstract
Adaptive responding to threatening stressors is of fundamental importance for survival. Dysfunctional hyperactivation of corticotropin releasing factor type-1 (CRF(1)) receptors in stress response system pathways is linked to stress-related psychopathology and CRF(1) receptor antagonists (CRAs) have been proposed as novel therapeutic agents. CRA effects in diverse animal models of stress that detect anxiolytics and/or antidepressants are reviewed, with the goal of evaluating their potential therapeutic utility in depression, anxiety, and other stress-related disorders. CRAs have a distinct phenotype in animals that has similarities to, and differences from, those of classic antidepressants and anxiolytics. CRAs are generally behaviorally silent, indicating that CRF(1) receptors are normally in a state of low basal activation. CRAs reduce stressor-induced HPA axis activation by blocking pituitary and possibly brain CRF(1) receptors which may ameliorate chronic stress-induced pathology. In animal models sensitive to anxiolytics and/or antidepressants, CRAs are generally more active in those with high stress levels, conditions which may maximize CRF(1) receptor hyperactivation. Clinically, CRAs have demonstrated good tolerability and safety, but have thus far lacked compelling efficacy in major depressive disorder, generalized anxiety disorder, or irritable bowel syndrome. CRAs may be best suited for disorders in which stressors clearly contribute to the underlying pathology (e.g. posttraumatic stress disorder, early life trauma, withdrawal/abstinence from addictive substances), though much work is needed to explore these possibilities. An evolving literature exploring the genetic, developmental and environmental factors linking CRF(1) receptor dysfunction to stress-related psychopathology is discussed in the context of improving the translational value of current animal models.
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Affiliation(s)
- John H Kehne
- Translational Neuropharmacology Consulting, LLC, 9710 Traville Gateway Drive #307, Rockville, MD 20850-7408, USA.
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CRF receptor blockade prevents initiation and consolidation of stress effects on affect in the predator stress model of PTSD. Int J Neuropsychopharmacol 2010; 13:747-57. [PMID: 19751543 PMCID: PMC3092595 DOI: 10.1017/s1461145709990496] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Post traumatic stress disorder (PTSD) is a chronic anxiety disorder initiated by an intensely threatening, traumatic event. There is a great need for more efficacious pharmacotherapy and preventive treatments for PTSD. In animals, corticotropin-releasing factor (CRF) and the CRF1 receptor play a critical role in behavioural and neuroendocrine responses to stress. We tested the hypothesis that CRF1 activation is required for initiation and consolidation of long-term effects of trauma on anxiety-like behaviour in the predator exposure (predator stress) model of PTSD. Male C57BL6 mice were treated with the selective CRF1 antagonist CRA0450 (2, 20 mg/kg) 30 min before or just after predator stress. Long-term effects of stress on rodent anxiety were measured 7 d later using acoustic startle, elevated plus maze (EPM), light/dark box, and hole-board tests. Predator stress increased startle amplitude and delayed startle habituation, increased time in and decreased exits from the dark chamber in the light/dark box test, and decreased risk assessment in the EPM. CRF1 antagonism had limited effects on these behaviours in non-stressed controls, with the high dose decreasing risk assessment in the EPM. However, in stressed animals CRF1 antagonism blocked initiation and consolidation of stressor effects on startle, and returned risk assessment to baseline levels in predator-stressed mice. These findings implicate CRF1 activation in initiation and post-trauma consolidation of predator stress effects on anxiety-like behaviour, specifically on increased arousal as measured by exaggerated startle behaviours. These data support further research of CRF1 antagonists as potential prophylactic treatments for PTSD.
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Holsboer F, Ising M. Stress hormone regulation: biological role and translation into therapy. Annu Rev Psychol 2010; 61:81-109, C1-11. [PMID: 19575614 DOI: 10.1146/annurev.psych.093008.100321] [Citation(s) in RCA: 277] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Stress is defined as a state of perturbed homeostasis following endangerment that evokes manifold adaptive reactions, which are summarized as the stress response. In the case of mental stress, the adaptive response follows the perception of endangerment. Different peptides, steroids, and biogenic amines operate the stress response within the brain and also after they have been released into circulation. We focus in this review on the biological roles of corticosteroids, corticotrophin-releasing hormone (CRH), and arginine vasopressin (AVP), and we evaluate the effects of treatments directed against the actions of these hormones. CRH and AVP are the central drivers of the stress hormone system, but they also act as neuromodulators in the brain, affecting higher mental functions including emotion, cognition, and behavior. When released toward the pituitary, these central neuropeptides elicit corticotrophin into the periphery, which activates corticosteroid release from the adrenal cortex. These stress hormones are essential for the adequate adaptation to stress, but they can also evoke severe clinical conditions once persistently hypersecreted. Depression and anxiety disorders are prominent examples of stress-related disorders associated with an impaired regulation of stress hormones. We summarize the effects of drugs acting at specific targets of the stress hormone axis, and we discuss their potential use as next-generation antidepressant medications. Such treatments require the identification of patients that will optimally benefit from such specific interventions. These could be a first step into personalized medicine using treatments tailored to the specific pathology of the patients.
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Affiliation(s)
- Florian Holsboer
- Max Planck Institute of Psychiatry, Kraepelinstr. 2-10, 80804 Munich, Germany.
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36
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Davis M, Walker DL, Miles L, Grillon C. Phasic vs sustained fear in rats and humans: role of the extended amygdala in fear vs anxiety. Neuropsychopharmacology 2010; 35:105-35. [PMID: 19693004 PMCID: PMC2795099 DOI: 10.1038/npp.2009.109] [Citation(s) in RCA: 1020] [Impact Index Per Article: 72.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Revised: 06/26/2009] [Accepted: 07/14/2009] [Indexed: 01/11/2023]
Abstract
Data will be reviewed using the acoustic startle reflex in rats and humans based on our attempts to operationally define fear vs anxiety. Although the symptoms of fear and anxiety are very similar, they also differ. Fear is a generally adaptive state of apprehension that begins rapidly and dissipates quickly once the threat is removed (phasic fear). Anxiety is elicited by less specific and less predictable threats, or by those that are physically or psychologically more distant. Thus, anxiety is a more long-lasting state of apprehension (sustained fear). Rodent studies suggest that phasic fear is mediated by the amygdala, which sends outputs to the hypothalamus and brainstem to produce symptoms of fear. Sustained fear is also mediated by the amygdala, which releases corticotropin-releasing factor, a stress hormone that acts on receptors in the bed nucleus of the stria terminalis (BNST), a part of the so-called 'extended amygdala.' The amygdala and BNST send outputs to the same hypothalamic and brainstem targets to produce phasic and sustained fear, respectively. In rats, sustained fear is more sensitive to anxiolytic drugs. In humans, symptoms of clinical anxiety are better detected in sustained rather than phasic fear paradigms.
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Affiliation(s)
- Michael Davis
- Department of Psychiatry, Yerkes National Primate Center, Emory University, and the Center for Behavioral Neuroscience, Atlanta, GA 30329, USA.
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37
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Hauger RL, Risbrough V, Oakley RH, Olivares-Reyes JA, Dautzenberg FM. Role of CRF receptor signaling in stress vulnerability, anxiety, and depression. Ann N Y Acad Sci 2009; 1179:120-43. [PMID: 19906236 DOI: 10.1111/j.1749-6632.2009.05011.x] [Citation(s) in RCA: 161] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Markers of hyperactive central corticotropin releasing factor (CRF) systems and CRF-related single nucleotide polymorphisms (SNPs) have been identified in patients with anxiety and depressive disorders. Designing more effective antagonists may now be guided by data showing that small molecules bind to transmembrane domains. Specifically, CRF(1) receptor antagonists have been developed as novel anxiolytic and antidepressant treatments. Because CRF(1) receptors become rapidly desensitized by G protein-coupled receptor kinase (GRK) and beta-arrestin mechanisms in the presence of high agonist concentrations, neuronal hypersecretion of synaptic CRF alone may be insufficient to account for excessive central CRF neurotransmission in stress-induced affective pathophysiology. In addition to desensitizing receptor function, GRK phosphorylation and beta-arrestin binding can shift a G protein-coupled receptor (GPCR) to signal selectively via the extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK-MAPK) or Akt pathways independent of G proteins. Also, Epac-dependent CRF(1) receptor signaling via the ERK-MAPK pathway has been found to potentiate brain-derived neurotrophic factor (BDNF)-stimulated TrkB signaling. Thus, genetic or acquired abnormalities in GRK and beta-arrestin function may be involved in the pathophysiology of stress-induced anxiety and depression.
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Affiliation(s)
- Richard L Hauger
- Psychiatry Service, VA Healthcare System, University of California, San Diego, La Jolla, California, USA.
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38
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Walker DL, Miles LA, Davis M. Selective participation of the bed nucleus of the stria terminalis and CRF in sustained anxiety-like versus phasic fear-like responses. Prog Neuropsychopharmacol Biol Psychiatry 2009; 33:1291-308. [PMID: 19595731 PMCID: PMC2783512 DOI: 10.1016/j.pnpbp.2009.06.022] [Citation(s) in RCA: 258] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Revised: 06/26/2009] [Accepted: 06/29/2009] [Indexed: 01/09/2023]
Abstract
The medial division of the central nucleus of the amygdala (CeA(M)) and the lateral division of the bed nucleus of the stria terminalis (BNST(L)) are closely related. Both receive projections from the basolateral amygdala (BLA) and both project to brain areas that mediate fear-influenced behaviors. In contrast to CeA(M) however, initial attempts to implicate the BNST in conditioned fear responses were largely unsuccessful. More recent studies have shown that the BNST does participate in some types of anxiety and stress responses. Here, we review evidence suggesting that the CeA(M) and BNST(L) are functionally complementary, with CeA(M) mediating short- but not long-duration threat responses (i.e., phasic fear) and BNST(L) mediating long- but not short-duration responses (sustained fear or 'anxiety'). We also review findings implicating the stress-related peptide corticotropin-releasing factor (CRF) in sustained but not phasic threat responses, and attempt to integrate these findings into a neural circuit model which accounts for these and related observations.
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Affiliation(s)
- D. L. Walker
- Department of Psychiatry and Behavioral Sciences, School of Medicine, Emory University, Atlanta, GA, USA,Correspondence should be addressed to: David L. Walker, Emory University School of Medicine, 954 Gatewood Road NE, Yerkes Neurosci Bldg – Rm 5214, Atlanta, GA 30329, Ph: (404) 727-3587, Fax: (404) 727-8070,
| | | | - M. Davis
- Department of Psychiatry and Behavioral Sciences, School of Medicine, Emory University, Atlanta, GA, USA,The Center for Behavior Neurosci, Emory University, Atlanta, GA, USA
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Pickens CL, Adams-Deutsch T, Nair SG, Navarre BM, Heilig M, Shaham Y. Effect of pharmacological manipulations of neuropeptide Y and corticotropin-releasing factor neurotransmission on incubation of conditioned fear. Neuroscience 2009; 164:1398-406. [PMID: 19800945 DOI: 10.1016/j.neuroscience.2009.09.079] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Accepted: 09/28/2009] [Indexed: 01/12/2023]
Abstract
We recently developed a procedure to study fear incubation in which rats given 100 tone-shock pairings over 10 days show low fear 2 days after conditioned fear training and high fear after 30 or 60 days. Here, we studied the role of the stress-related peptides, neuropeptide Y (NPY) and corticotropin-releasing factor (CRF), in fear incubation. We gave rats either 10 or 100 30-s tone-0.5-s footshock pairings over 1 day (short training) or 10 days (long training) and then assessed tone-cue-induced conditioned suppression of lever responding 2 days after short training or 2 days and 1 month after long training. Prior to testing, we injected NPY (5-10 microg, i.c.v.), the NPY Y1 receptor antagonist BIBO3304 (20-40 microg, i.c.v.), the NPY Y2 receptor antagonist BIIE0246 (2.5-5 mg/kg s.c.), the non-selective CRF receptor antagonist D-Phe CRF(12-41) (10 microg, i.c.v.), or the CRF1 receptor antagonist MTIP (10-20 mg/kg s.c.). Conditioned suppression after long training was higher after 1 month than after 2 days (fear incubation); conditioned suppression was robustly expressed 2 days after short training (non-incubated fear). Both incubated and non-incubated fear responses were attenuated by NPY. In contrast, D-Phe CRF(12-41), MTIP, BIBO3304, or BIIE0246 had no effect on conditioned fear at the different time points. Results confirm previous work on the potent effect of exogenous NPY administration on conditioned fear, but the negative results with BIBO3304 and BIIE0246 question whether endogenous NPY contributes to incubated (or non-incubated) fear. Results also suggest that CRF receptors are not involved in cue-induced fear in the conditioned suppression procedure.
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Affiliation(s)
- C L Pickens
- Department of Health and Human Services, Behavioral Neuroscience Branch, Intramural Research Program-National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21218, USA
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Fadok JP, Dickerson TMK, Palmiter RD. Dopamine is necessary for cue-dependent fear conditioning. J Neurosci 2009; 29:11089-97. [PMID: 19741115 PMCID: PMC2759996 DOI: 10.1523/jneurosci.1616-09.2009] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2009] [Revised: 06/15/2009] [Accepted: 07/06/2009] [Indexed: 11/21/2022] Open
Abstract
Dopamine (DA) is implicated in many behaviors, including motor function, cognition, and reward processing; however, the role of DA in fear processing remains equivocal. To examine the role of DA in fear-related learning, dopamine-deficient (DD) mice were tested in a fear-potentiated startle paradigm. DA synthesis can be restored in DD mice through administration of 3, 4-dihydroxy-l-phenylalanine (l-Dopa), thereby permitting the assessment of fear processing in either a DA-depleted or -replete state. Fear-potentiated startle was absent in DD mice but could be restored by l-Dopa administration immediately after fear conditioning. Selective viral-mediated restoration of DA synthesis within the ventral tegmental area fully restored fear learning in DD mice, and restoration of DA synthesis to DA neurons projecting to the basolateral amygdala restored short-term memory but not long-term memory or shock sensitization. We also demonstrate that the DA D(1) receptor (D(1)R) and D(2)-like receptors are necessary for cue-dependent fear learning. These findings indicate that DA acting on multiple receptor subtypes within multiple target regions facilitates the stabilization of fear memory.
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Affiliation(s)
- Jonathan P. Fadok
- Graduate Program in Neurobiology and Behavior and
- Department of Biochemistry and Howard Hughes Medical Institute, University of Washington, Seattle, Washington 98195
| | - Tavis M. K. Dickerson
- Department of Biochemistry and Howard Hughes Medical Institute, University of Washington, Seattle, Washington 98195
| | - Richard D. Palmiter
- Department of Biochemistry and Howard Hughes Medical Institute, University of Washington, Seattle, Washington 98195
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Pitts MW, Todorovic C, Blank T, Takahashi LK. The central nucleus of the amygdala and corticotropin-releasing factor: insights into contextual fear memory. J Neurosci 2009; 29:7379-88. [PMID: 19494159 PMCID: PMC2771694 DOI: 10.1523/jneurosci.0740-09.2009] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2009] [Revised: 04/30/2009] [Accepted: 05/02/2009] [Indexed: 11/21/2022] Open
Abstract
The central nucleus of the amygdala (CeA) has been traditionally viewed in fear conditioning to serve as an output neural center that transfers conditioned information formed in the basolateral amygdala to brain structures that generate emotional responses. Recent studies suggest that the CeA may also be involved in fear memory consolidation. In addition, corticotropin-releasing factor systems were shown to facilitate memory consolidation in the amygdala, which contains a high density of CRF immunoreactive cell bodies and fibers in the lateral part of the CeA (CeAl). However, the involvement of CeA CRF in contextual fear conditioning remains poorly understood. Therefore, we first conducted a series of studies using fiber-sparing lesion and reversible inactivation methods to assess the general role of the CeA in contextual fear. We then used identical training and testing procedures to compare and evaluate the specific function of CeA CRF using CRF antisense oligonucleotides (CRF ASO). Rats microinjected with ibotenic acid, muscimol, or a CRF ASO into the CeA before contextual fear conditioning showed typical levels of freezing during acquisition training but exhibited significant reductions in contextual freezing in a retention test 48 h later. Furthermore, CeA inactivation induced by either muscimol or CRF ASO administration immediately before retention testing did not impair freezing, suggesting that the previously observed retention deficits were caused by inhibition of consolidation rather than fear expression. Collectively, our results suggest CeA involvement in the consolidation of contextual fear memory and specifically implicate CeA CRF as an important mediator.
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Affiliation(s)
| | - Cedomir Todorovic
- Specialized Neuroscience Research Project 2, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii 96813, and
| | - Thomas Blank
- Specialized Neuroscience Research Project 2, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii 96813, and
| | - Lorey K. Takahashi
- Department of Cell & Molecular Biology and
- Department of Psychology, University of Hawaii, Honolulu, Hawaii 96822
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