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Hamati R, Ahrens J, Shvetz C, Holahan MR, Tuominen L. 65 years of research on dopamine's role in classical fear conditioning and extinction: A systematic review. Eur J Neurosci 2024; 59:1099-1140. [PMID: 37848184 DOI: 10.1111/ejn.16157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 09/08/2023] [Accepted: 09/13/2023] [Indexed: 10/19/2023]
Abstract
Dopamine, a catecholamine neurotransmitter, has historically been associated with the encoding of reward, whereas its role in aversion has received less attention. Here, we systematically gathered the vast evidence of the role of dopamine in the simplest forms of aversive learning: classical fear conditioning and extinction. In the past, crude methods were used to augment or inhibit dopamine to study its relationship with fear conditioning and extinction. More advanced techniques such as conditional genetic, chemogenic and optogenetic approaches now provide causal evidence for dopamine's role in these learning processes. Dopamine neurons encode conditioned stimuli during fear conditioning and extinction and convey the signal via activation of D1-4 receptor sites particularly in the amygdala, prefrontal cortex and striatum. The coordinated activation of dopamine receptors allows for the continuous formation, consolidation, retrieval and updating of fear and extinction memory in a dynamic and reciprocal manner. Based on the reviewed literature, we conclude that dopamine is crucial for the encoding of classical fear conditioning and extinction and contributes in a way that is comparable to its role in encoding reward.
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Affiliation(s)
- Rami Hamati
- Neuroscience Graduate Program, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
- University of Ottawa Institute of Mental Health Research, University of Ottawa, Ottawa, Ontario, Canada
| | - Jessica Ahrens
- Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada
| | - Cecelia Shvetz
- University of Ottawa Institute of Mental Health Research, University of Ottawa, Ottawa, Ontario, Canada
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada
| | - Matthew R Holahan
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada
| | - Lauri Tuominen
- University of Ottawa Institute of Mental Health Research, University of Ottawa, Ottawa, Ontario, Canada
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada
- Department of Psychiatry, University of Ottawa, Ottawa, Ontario, Canada
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2
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Sepahvand T, Power KD, Qin T, Yuan Q. The Basolateral Amygdala: The Core of a Network for Threat Conditioning, Extinction, and Second-Order Threat Conditioning. BIOLOGY 2023; 12:1274. [PMID: 37886984 PMCID: PMC10604397 DOI: 10.3390/biology12101274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 09/14/2023] [Accepted: 09/20/2023] [Indexed: 10/28/2023]
Abstract
Threat conditioning, extinction, and second-order threat conditioning studied in animal models provide insight into the brain-based mechanisms of fear- and anxiety-related disorders and their treatment. Much attention has been paid to the role of the basolateral amygdala (BLA) in such processes, an overview of which is presented in this review. More recent evidence suggests that the BLA serves as the core of a greater network of structures in these forms of learning, including associative and sensory cortices. The BLA is importantly regulated by hippocampal and prefrontal inputs, as well as by the catecholaminergic neuromodulators, norepinephrine and dopamine, that may provide important prediction-error or learning signals for these forms of learning. The sensory cortices may be required for the long-term storage of threat memories. As such, future research may further investigate the potential of the sensory cortices for the long-term storage of extinction and second-order conditioning memories.
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Affiliation(s)
| | | | | | - Qi Yuan
- Biomedical Sciences, Faculty of Medicine, Memorial University, St John’s, NL A1B 3V6, Canada; (T.S.); (K.D.P.); (T.Q.)
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3
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Webler RD, Oathes DJ, van Rooij SJH, Gewirtz JC, Nahas Z, Lissek SM, Widge AS. Causally mapping human threat extinction relevant circuits with depolarizing brain stimulation methods. Neurosci Biobehav Rev 2023; 144:105005. [PMID: 36549377 PMCID: PMC10210253 DOI: 10.1016/j.neubiorev.2022.105005] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 11/17/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022]
Abstract
Laboratory threat extinction paradigms and exposure-based therapy both involve repeated, safe confrontation with stimuli previously experienced as threatening. This fundamental procedural overlap supports laboratory threat extinction as a compelling analogue of exposure-based therapy. Threat extinction impairments have been detected in clinical anxiety and may contribute to exposure-based therapy non-response and relapse. However, efforts to improve exposure outcomes using techniques that boost extinction - primarily rodent extinction - have largely failed to date, potentially due to fundamental differences between rodent and human neurobiology. In this review, we articulate a comprehensive pre-clinical human research agenda designed to overcome these failures. We describe how connectivity guided depolarizing brain stimulation methods (i.e., TMS and DBS) can be applied concurrently with threat extinction and dual threat reconsolidation-extinction paradigms to causally map human extinction relevant circuits and inform the optimal integration of these methods with exposure-based therapy. We highlight candidate targets including the amygdala, hippocampus, ventromedial prefrontal cortex, dorsal anterior cingulate cortex, and mesolimbic structures, and propose hypotheses about how stimulation delivered at specific learning phases could strengthen threat extinction.
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Affiliation(s)
- Ryan D Webler
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA.
| | - Desmond J Oathes
- Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Sanne J H van Rooij
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA
| | - Jonathan C Gewirtz
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA; Department of Psychology, Arizona State University, AZ, USA
| | - Ziad Nahas
- Department of Psychology, Arizona State University, AZ, USA
| | - Shmuel M Lissek
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA
| | - Alik S Widge
- Department of Psychiatry and Medical Discovery Team on Addictions, University of Minnesota Medical School, MN, USA
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4
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Laing PAF, Felmingham KL, Davey CG, Harrison BJ. The neurobiology of Pavlovian safety learning: Towards an acquisition-expression framework. Neurosci Biobehav Rev 2022; 142:104882. [PMID: 36150453 DOI: 10.1016/j.neubiorev.2022.104882] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 09/15/2022] [Accepted: 09/16/2022] [Indexed: 11/19/2022]
Abstract
Safety learning creates associations between conditional stimuli and the absence of threat. Studies of human fear conditioning have accumulated evidence for the neural signatures of safety over various paradigms, aligning on several common brain systems. While these systems are often interpreted as underlying safety learning in a generic sense, they may instead reflect the expression of learned safety, pertaining to processes of fear inhibition, positive affect, and memory. Animal models strongly suggest these can be separable from neural circuits implicated in the conditioning process itself (or safety acquisition). While acquisition-expression distinctions are ubiquitous in behavioural science, this lens has not been applied to safety learning, which remains a novel area in the field. In this mini-review, we overview findings from prevalent safety paradigms in humans, and synthesise these with insights from animal models to propose that the neurobiology of safety learning be conceptualised along an acquisition-expression model, with the aim of stimulating richer brain-based characterisations of this important process.
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Affiliation(s)
- Patrick A F Laing
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne, Australia.
| | - Kim L Felmingham
- Melbourne School of Psychological Sciences, The University of Melbourne, Australia
| | - Christopher G Davey
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne, Australia
| | - Ben J Harrison
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne, Australia.
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5
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Yan Y, Aierken A, Wang C, Jin W, Quan Z, Wang Z, Qing H, Ni J, Zhao J. Neuronal Circuits Associated with Fear Memory: Potential Therapeutic Targets for Posttraumatic Stress Disorder. Neuroscientist 2022; 29:332-351. [PMID: 35057666 DOI: 10.1177/10738584211069977] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Posttraumatic stress disorder (PTSD) is a psychiatric disorder that is associated with long-lasting memories of traumatic experiences. Extinction and discrimination of fear memory have become therapeutic targets for PTSD. Newly developed optogenetics and advanced in vivo imaging techniques have provided unprecedented spatiotemporal tools to characterize the activity, connectivity, and functionality of specific cell types in complicated neuronal circuits. The use of such tools has offered mechanistic insights into the exquisite organization of the circuitry underlying the extinction and discrimination of fear memory. This review focuses on the acquisition of more detailed, comprehensive, and integrated neural circuits to understand how the brain regulates the extinction and discrimination of fear memory. A future challenge is to translate these researches into effective therapeutic treatment for PTSD from the perspective of precise regulation of the neural circuits associated with the extinction and discrimination of fear memories.
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Affiliation(s)
- Yan Yan
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Ailikemu Aierken
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Chunjian Wang
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Wei Jin
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Zhenzhen Quan
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Zhe Wang
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
- The National Clinical Research Center for Geriatric Disease, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Hong Qing
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Junjun Ni
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Juan Zhao
- School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, China
- Aerospace Medical Center, Aerospace Center Hospital, Beijing, China
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6
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Esser R, Korn CW, Ganzer F, Haaker J. L-DOPA modulates activity in the vmPFC, nucleus accumbens, and VTA during threat extinction learning in humans. eLife 2021; 10:65280. [PMID: 34473055 PMCID: PMC8443250 DOI: 10.7554/elife.65280] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 09/01/2021] [Indexed: 12/26/2022] Open
Abstract
Learning to be safe is central for adaptive behaviour when threats are no longer present. Detecting the absence of an expected threat is key for threat extinction learning and an essential process for the behavioural treatment of anxiety-related disorders. One possible mechanism underlying extinction learning is a dopaminergic mismatch signal that encodes the absence of an expected threat. Here we show that such a dopamine-related pathway underlies extinction learning in humans. Dopaminergic enhancement via administration of L-DOPA (vs. Placebo) was associated with reduced retention of differential psychophysiological threat responses at later test, which was mediated by activity in the ventromedial prefrontal cortex that was specific to extinction learning. L-DOPA administration enhanced signals at the time-point of an expected, but omitted threat in extinction learning within the nucleus accumbens, which were functionally coupled with the ventral tegmental area and the amygdala. Computational modelling of threat expectancies further revealed prediction error encoding in nucleus accumbens that was reduced when L-DOPA was administered. Our results thereby provide evidence that extinction learning is influenced by L-DOPA and provide a mechanistic perspective to augment extinction learning by dopaminergic enhancement in humans.
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Affiliation(s)
- Roland Esser
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christoph W Korn
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Section Social Neuroscience, Department of General Psychiatry, Heidelberg, Germany
| | - Florian Ganzer
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,German Center for Addiction Research in Childhood and Adolescence, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jan Haaker
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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7
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Bouton ME, Maren S, McNally GP. BEHAVIORAL AND NEUROBIOLOGICAL MECHANISMS OF PAVLOVIAN AND INSTRUMENTAL EXTINCTION LEARNING. Physiol Rev 2021; 101:611-681. [PMID: 32970967 PMCID: PMC8428921 DOI: 10.1152/physrev.00016.2020] [Citation(s) in RCA: 153] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
This article reviews the behavioral neuroscience of extinction, the phenomenon in which a behavior that has been acquired through Pavlovian or instrumental (operant) learning decreases in strength when the outcome that reinforced it is removed. Behavioral research indicates that neither Pavlovian nor operant extinction depends substantially on erasure of the original learning but instead depends on new inhibitory learning that is primarily expressed in the context in which it is learned, as exemplified by the renewal effect. Although the nature of the inhibition may differ in Pavlovian and operant extinction, in either case the decline in responding may depend on both generalization decrement and the correction of prediction error. At the neural level, Pavlovian extinction requires a tripartite neural circuit involving the amygdala, prefrontal cortex, and hippocampus. Synaptic plasticity in the amygdala is essential for extinction learning, and prefrontal cortical inhibition of amygdala neurons encoding fear memories is involved in extinction retrieval. Hippocampal-prefrontal circuits mediate fear relapse phenomena, including renewal. Instrumental extinction involves distinct ensembles in corticostriatal, striatopallidal, and striatohypothalamic circuits as well as their thalamic returns for inhibitory (extinction) and excitatory (renewal and other relapse phenomena) control over operant responding. The field has made significant progress in recent decades, although a fully integrated biobehavioral understanding still awaits.
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Affiliation(s)
- Mark E Bouton
- Department of Psychological Science, University of Vermont, Burlington, Vermont
| | - Stephen Maren
- Department of Psychological and Brain Sciences and Institute for Neuroscience, Texas A&M University, College Station, Texas
| | - Gavan P McNally
- School of Psychology, University of New South Wales, Sydney, Australia
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8
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Ney LJ, Akhurst J, Bruno R, Laing PAF, Matthews A, Felmingham KL. Dopamine, endocannabinoids and their interaction in fear extinction and negative affect in PTSD. Prog Neuropsychopharmacol Biol Psychiatry 2021; 105:110118. [PMID: 32991952 DOI: 10.1016/j.pnpbp.2020.110118] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 09/03/2020] [Accepted: 09/22/2020] [Indexed: 12/13/2022]
Abstract
There currently exist few frameworks for common neurobiology between reexperiencing and negative cognitions and mood symptoms of PTSD. Adopting a dopaminergic framework for PTSD unites many aspects of unique symptom clusters, and this approach also links PTSD symptomology to common comorbidities with a common neurobiological deficiency. Here we review the dopamine literature and incorporate it with a growing field of research that describes both the contribution of endocannabinoids to fear extinction and PTSD, as well as the interactions between dopaminergic and endocannabinoid systems underlying this disorder. Based on current evidence, we outline an early, preliminary model that links re-experiencing and negative cognitions and mood in PTSD by invoking the interaction between endocannabinoid and dopaminergic signalling in the brain. These interactions between PTSD, dopamine and endocannabinoids may have implications for future therapies for treatment-resistant and comorbid PTSD patients.
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Affiliation(s)
- Luke J Ney
- School of Psychology, University of Tasmania, Australia.
| | - Jane Akhurst
- School of Psychology, University of Tasmania, Australia
| | | | - Patrick A F Laing
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, University of Melbourne & Melbourne Health, Australia
| | | | - Kim L Felmingham
- School of Psychological Sciences, University of Melbourne, Australia
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9
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Vega-Torres JD, Azadian M, Rios-Orsini RA, Reyes-Rivera AL, Ontiveros-Angel P, Figueroa JD. Adolescent Vulnerability to Heightened Emotional Reactivity and Anxiety After Brief Exposure to an Obesogenic Diet. Front Neurosci 2020; 14:562. [PMID: 32694970 PMCID: PMC7338851 DOI: 10.3389/fnins.2020.00562] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 05/06/2020] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Emerging evidence demonstrates that diet-induced obesity disrupts corticolimbic circuits underlying emotional regulation. Studies directed at understanding how obesity alters brain and behavior are easily confounded by a myriad of complications related to obesity. This study investigated the early neurobiological stress response triggered by an obesogenic diet. Furthermore, this study directly determined the combined impact of a short-term obesogenic diet and adolescence on critical behavioral and molecular substrates implicated in emotion regulation and stress. METHODS Adolescent (postnatal day 31) or adult (postnatal day 81) Lewis rats were fed for 1 week with an experimental Western-like high-saturated fat diet (WD, 41% kcal from fat) or a matched control diet (CD, 13% kcal from fat). We used the acoustic fear-potentiated startle (FPS) paradigm to determine the effects of the WD on cued fear conditioning and fear extinction. We used c-Fos mapping to determine the functional influence of the diet and stress on corticolimbic circuits. RESULTS We report that 1-week WD consumption was sufficient to induce fear extinction deficits in adolescent rats, but not in adult rats. We identify fear-induced alterations in corticolimbic neuronal activation and demonstrate increased prefrontal cortex CRHR1 messenger RNA (mRNA) levels in the rats that consumed the WD. CONCLUSION Our findings demonstrate that short-term consumption of an obesogenic diet during adolescence heightens behavioral and molecular vulnerabilities associated with risk for anxiety and stress-related disorders. Given that fear extinction promotes resilience and that fear extinction principles are the foundation of psychological treatments for posttraumatic stress disorder (PTSD), understanding how obesogenic environments interact with the adolescent period to affect the acquisition and expression of fear extinction memories is of tremendous clinical relevance.
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Affiliation(s)
- Julio D. Vega-Torres
- Physiology Division, Department of Basic Sciences, Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Loma Linda, CA, United States
| | - Matine Azadian
- Stanford University School of Medicine, Stanford, CA, United States
| | | | | | - Perla Ontiveros-Angel
- Physiology Division, Department of Basic Sciences, Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Loma Linda, CA, United States
| | - Johnny D. Figueroa
- Physiology Division, Department of Basic Sciences, Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Loma Linda, CA, United States
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10
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Papalini S, Beckers T, Vervliet B. Dopamine: from prediction error to psychotherapy. Transl Psychiatry 2020; 10:164. [PMID: 32451377 PMCID: PMC7248121 DOI: 10.1038/s41398-020-0814-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 04/14/2020] [Accepted: 04/21/2020] [Indexed: 02/07/2023] Open
Abstract
Dopamine, one of the main neurotransmitters in the mammalian brain, has been implicated in the coding of prediction errors that govern reward learning as well as fear extinction learning. Psychotherapy too can be viewed as a form of error-based learning, because it challenges erroneous beliefs and behavioral patterns in order to induce long-term changes in emotions, cognitions, and behaviors. Exposure therapy, for example, relies in part on fear extinction principles to violate erroneous expectancies of danger and induce novel safety learning that inhibits and therefore reduces fear in the long term. As most forms of psychotherapy, however, exposure therapy suffers from non-response, dropout, and relapse. This narrative review focuses on the role of midbrain and prefrontal dopamine in novel safety learning and investigates possible pathways through which dopamine-based interventions could be used as an adjunct to improve both the response and the long-term effects of the therapy. Convincing evidence exists for an involvement of the midbrain dopamine system in the acquisition of new, safe memories. Additionally, prefrontal dopamine is emerging as a key ingredient for the consolidation of fear extinction. We propose that applying a dopamine prediction error perspective to psychotherapy can inspire both pharmacological and non-pharmacological studies aimed at discovering innovative ways to enhance the acquisition of safety memories. Additionally, we call for further empirical investigations on dopamine-oriented drugs that might be able to maximize consolidation of successful fear extinction and its long-term retention after therapy, and we propose to also include investigations on non-pharmacological interventions with putative prefrontal dopaminergic effects, like working memory training.
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Affiliation(s)
- Silvia Papalini
- Laboratory of Biological Psychology (LBP), Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium. .,Leuven Brain Institute, KU Leuven, Leuven, Belgium.
| | - Tom Beckers
- grid.5596.f0000 0001 0668 7884Leuven Brain Institute, KU Leuven, Leuven, Belgium ,grid.5596.f0000 0001 0668 7884Centre for the Psychology of Learning and Experimental Psychopathology (CLEP), Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium
| | - Bram Vervliet
- grid.5596.f0000 0001 0668 7884Laboratory of Biological Psychology (LBP), Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium ,grid.5596.f0000 0001 0668 7884Leuven Brain Institute, KU Leuven, Leuven, Belgium
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11
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Stubbendorff C, Stevenson CW. Dopamine regulation of contextual fear and associated neural circuit function. Eur J Neurosci 2020; 54:6933-6947. [DOI: 10.1111/ejn.14772] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 04/29/2020] [Accepted: 05/01/2020] [Indexed: 01/07/2023]
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12
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Abstract
Animal studies have demonstrated that catecholamines regulate several aspects of fear conditioning. In humans, however, pharmacological manipulations of the catecholaminergic system have been scarce, and their primary focus has been to interfering with catecholaminergic activity after fear acquisition or expression had taken place, using L-Dopa, primarily, as catecholaminergic precursor. Here, we sought to determine if putative increases in presynaptic dopamine and norepinephrine by tyrosine administered before conditioning could affect fear expression. Electrodermal activity (EDA) of 46 healthy participants (24 placebo, 22 tyrosine) was measured in an instructed fear task. Results showed that tyrosine abolished fear expression compared to placebo. Importantly, tyrosine did not affect EDA responses to the aversive stimulus (UCS) or alter participants’ mood. Therefore, the effect of tyrosine on fear expression cannot be attributed to these factors. Taken together, these findings provide evidence that the catecholaminergic system influences fear expression in humans.
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13
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Velasco ER, Florido A, Milad MR, Andero R. Sex differences in fear extinction. Neurosci Biobehav Rev 2019; 103:81-108. [PMID: 31129235 PMCID: PMC6692252 DOI: 10.1016/j.neubiorev.2019.05.020] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 03/08/2019] [Accepted: 05/19/2019] [Indexed: 12/18/2022]
Abstract
Despite the exponential increase in fear research during the last years, few studies have included female subjects in their design. The need to include females arises from the knowledge gap of mechanistic processes underlying the behavioral and neural differences observed in fear extinction. Moreover, the exact contribution of sex and hormones in relation to learning and behavior is still largely unknown. Insights from this field could be beneficial as fear-related disorders are twice as prevalent in women compared to men. Here, we review an up-to-date summary of animal and human studies in adulthood that report sex differences in fear extinction from a structural and functional approach. Furthermore, we describe how these factors could contribute to the observed sex differences in fear extinction during normal and pathological conditions.
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Affiliation(s)
- E R Velasco
- Institut de Neurociències, Universitat Autònoma de Barcelona, Spain
| | - A Florido
- Institut de Neurociències, Universitat Autònoma de Barcelona, Spain
| | - M R Milad
- Department of Psychiatry, University of Illinois at Chicago, USA
| | - R Andero
- Institut de Neurociències, Universitat Autònoma de Barcelona, Spain; CIBERSAM, Corporació Sanitaria Parc Taulí, Sabadell, Spain; Department of Psychobiology and Methodology of Health Sciences, Universitat Autònoma de Barcelona, Spain.
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14
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King G, Baker KD, Bisby MA, Chan D, Cowan CSM, Stylianakis AA, Zimmermann KS, Richardson R. A precision medicine approach to pharmacological adjuncts to extinction: a call to broaden research. Psychopharmacology (Berl) 2019; 236:143-161. [PMID: 30116858 DOI: 10.1007/s00213-018-4999-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 08/07/2018] [Indexed: 12/21/2022]
Abstract
There is a pressing need to improve treatments for anxiety. Although exposure-based therapy is currently the gold-standard treatment, many people either do not respond to this therapy or experience a relapse of symptoms after treatment has ceased. In recent years, there have been many novel pharmacological agents identified in preclinical research that have potential as adjuncts for exposure therapy, yet very few of these are regularly integrated into clinical practice. Unfortunately, the robust effects observed in the laboratory animal often do not translate to a clinical population. In this review, we discuss how age, sex, genetics, stress, medications, diet, alcohol, and the microbiome can vary across a clinical population and yet are rarely considered in drug development. While not an exhaustive list, we have focused on these factors because they have been shown to influence an individual's vulnerability to anxiety and alter the neurotransmitter systems often targeted by pharmacological adjuncts to therapy. We argue that for potential adjuncts to be successfully translated from the lab to the clinic empirical research must be broadened to consider how individual difference factors will influence drug efficacy.
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Affiliation(s)
- Gabrielle King
- School of Psychology, The University of New South Wales, Sydney, Australia.
| | - Kathryn D Baker
- School of Psychology, The University of New South Wales, Sydney, Australia
| | - Madelyne A Bisby
- School of Psychology, The University of New South Wales, Sydney, Australia
| | - Diana Chan
- School of Psychology, The University of New South Wales, Sydney, Australia
| | | | | | | | - Rick Richardson
- School of Psychology, The University of New South Wales, Sydney, Australia
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15
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Gerlicher AMV, Tüscher O, Kalisch R. L-DOPA improves extinction memory retrieval after successful fear extinction. Psychopharmacology (Berl) 2019; 236:3401-3412. [PMID: 31243481 PMCID: PMC6892771 DOI: 10.1007/s00213-019-05301-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 06/05/2019] [Indexed: 11/30/2022]
Abstract
RATIONALE A promising strategy to prevent a return of fear after exposure-based therapy in anxiety disorders is to pharmacologically enhance the extinction memory consolidation presumed to occur after exposure. Accumulating evidence suggests that the effect of a number of pharmacological consolidation enhancers depends on a successful fear reduction during exposure. Here, we employed the dopamine precursor L-DOPA to clarify whether its documented potential to enhance extinction memory consolidation is dependent on successful fear extinction. METHODS In two double-blind, randomized and placebo-controlled experiments (experiment 1: N = 79, experiment 2: N = 32) comprising fear conditioning (day 1), extinction followed by administration of 150 mg L-DOPA or placebo (day 2) and a memory test (day 3) in healthy male adults, conditioned responses were assessed as differential skin conductance responses. We tested whether the effect of L-DOPA on conditioned responses at test depended on conditioned responses at the end of extinction in an experiment with a short (10 trials, experiment 1) and long (25 trials, experiment 2) extinction session. RESULTS In both experiments, the effect of L-DOPA was dependent on conditioned responses at the end of extinction. That is, post-extinction L-DOPA compared to placebo administration reduced conditioned responses at test only in participants showing a complete reduction of conditioned fear at the end of extinction. CONCLUSION The results support the potential use of L-DOPA as a pharmacological adjunct to exposure treatment, but point towards a common boundary condition for pharmacological consolidation enhancers: a successful reduction of fear in the exposure session.
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Affiliation(s)
- A. M. V. Gerlicher
- Neuroimaging Center (NIC), Focus Program Translational Neuroscience (FTN), Johannes Gutenberg University Medical Center, Langenbeckstr. 1, 55131 Mainz, Germany ,Deutsches Resilienz Zentrum (DRZ), Johannes Gutenberg University Medical Center, Untere Zahlbacher Str. 8, 55131 Mainz, Germany ,Present Address: Department of Clinical Psychology, University of Amsterdam, Nieuwe Achtergracht 129B, 1018 WS Amsterdam, The Netherlands
| | - O. Tüscher
- Deutsches Resilienz Zentrum (DRZ), Johannes Gutenberg University Medical Center, Untere Zahlbacher Str. 8, 55131 Mainz, Germany ,Department of Psychiatry and Psychotherapy, Johannes Gutenberg University Medical Center, Untere Zahlbacher Str. 8, 55131 Mainz, Germany
| | - R. Kalisch
- Neuroimaging Center (NIC), Focus Program Translational Neuroscience (FTN), Johannes Gutenberg University Medical Center, Langenbeckstr. 1, 55131 Mainz, Germany ,Deutsches Resilienz Zentrum (DRZ), Johannes Gutenberg University Medical Center, Untere Zahlbacher Str. 8, 55131 Mainz, Germany
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16
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Goode TD, Maren S. Common neurocircuitry mediating drug and fear relapse in preclinical models. Psychopharmacology (Berl) 2019; 236:415-437. [PMID: 30255379 PMCID: PMC6373193 DOI: 10.1007/s00213-018-5024-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 09/03/2018] [Indexed: 12/21/2022]
Abstract
BACKGROUND Comorbidity of anxiety disorders, stressor- and trauma-related disorders, and substance use disorders is extremely common. Moreover, therapies that reduce pathological fear and anxiety on the one hand, and drug-seeking on the other, often prove short-lived and are susceptible to relapse. Considerable advances have been made in the study of the neurobiology of both aversive and appetitive extinction, and this work reveals shared neural circuits that contribute to both the suppression and relapse of conditioned responses associated with trauma or drug use. OBJECTIVES The goal of this review is to identify common neural circuits and mechanisms underlying relapse across domains of addiction biology and aversive learning in preclinical animal models. We focus primarily on neural circuits engaged during the expression of relapse. KEY FINDINGS After extinction, brain circuits involving the medial prefrontal cortex and hippocampus come to regulate the expression of conditioned responses by the amygdala, bed nucleus of the stria terminalis, and nucleus accumbens. During relapse, hippocampal projections to the prefrontal cortex inhibit the retrieval of extinction memories resulting in a loss of inhibitory control over fear- and drug-associated conditional responding. CONCLUSIONS The overlapping brain systems for both fear and drug memories may explain the co-occurrence of fear and drug-seeking behaviors.
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Affiliation(s)
- Travis D Goode
- Department of Psychological and Brain Sciences and Institute for Neuroscience, Texas A&M University, 301 Old Main Dr., College Station, TX, 77843-3474, USA
| | - Stephen Maren
- Department of Psychological and Brain Sciences and Institute for Neuroscience, Texas A&M University, 301 Old Main Dr., College Station, TX, 77843-3474, USA.
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17
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Abstract
Several studies have revealed that fear recovery is prevented when extinction training is conducted after retrieval of a fear memory. Postretrieval extinction training is related to modification of memory during reconsolidation. Providing new information during reconsolidation can modify the original memory. We propose that avoidance behavior is a relevant factor that prevents subjects from obtaining new safety information during reconsolidation. Postretrieval extinction training without avoidance behavior reduced the fear response to conditioned stimulus and prevented spontaneous recovery in the current study, which corresponded with previous studies. Under the condition of postretrieval extinction training with avoidance behavior, the fear response was not reduced as much as it was in the condition without avoidance. It is possible that avoidance behavior prevents receiving new safety information during postretrieval extinction training.
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18
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Sevenster D, Visser RM, D'Hooge R. A translational perspective on neural circuits of fear extinction: Current promises and challenges. Neurobiol Learn Mem 2018; 155:113-126. [PMID: 29981423 PMCID: PMC6805216 DOI: 10.1016/j.nlm.2018.07.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 06/20/2018] [Accepted: 07/03/2018] [Indexed: 02/07/2023]
Abstract
Fear extinction is the well-known process of fear reduction through repeated re-exposure to a feared stimulus without the aversive outcome. The last two decades have witnessed a surge of interest in extinction learning. First, extinction learning is observed across species, and especially research on rodents has made great strides in characterising the physical substrate underlying extinction learning. Second, extinction learning is considered of great clinical significance since it constitutes a crucial component of exposure treatment. While effective in reducing fear responding in the short term, extinction learning can lose its grip, resulting in a return of fear (i.e., laboratory model for relapse of anxiety symptoms in patients). Optimization of extinction learning is, therefore, the subject of intense investigation. It is thought that the success of extinction learning is, at least partly, determined by the mismatch between what is expected and what actually happens (prediction error). However, while much of our knowledge about the neural circuitry of extinction learning and factors that contribute to successful extinction learning comes from animal models, translating these findings to humans has been challenging for a number of reasons. Here, we present an overview of what is known about the animal circuitry underlying extinction of fear, and the role of prediction error. In addition, we conducted a systematic literature search to evaluate the degree to which state-of-the-art neuroimaging methods have contributed to translating these findings to humans. Results show substantial overlap between networks in animals and humans at a macroscale, but current imaging techniques preclude comparisons at a smaller scale, especially in sub-cortical areas that are functionally heterogeneous. Moreover, human neuroimaging shows the involvement of numerous areas that are not typically studied in animals. Results obtained in research aimed to map the extinction circuit are largely dependent on the methods employed, not only across species, but also across human neuroimaging studies. Directions for future research are discussed.
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Affiliation(s)
- Dieuwke Sevenster
- Laboratory of Biological Psychology, Department of Psychology, KU Leuven, Tiensestraat 102, B-3000 Leuven, Belgium; Clinical Psychology, Utrecht University, Heidelberglaan 1, 3584 CS Utrecht, The Netherlands.
| | - Renée M Visser
- Medical Research Council Cognition and Brain Sciences Unit, University of Cambridge, 15 Chaucer Road, Cambridge CB2 7EF, United Kingdom
| | - Rudi D'Hooge
- Laboratory of Biological Psychology, Department of Psychology, KU Leuven, Tiensestraat 102, B-3000 Leuven, Belgium
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19
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Panitz C, Sperl MF, Hennig J, Klucken T, Hermann C, Mueller EM. Fearfulness, neuroticism/anxiety, and COMT Val158Met in long-term fear conditioning and extinction. Neurobiol Learn Mem 2018; 155:7-20. [DOI: 10.1016/j.nlm.2018.06.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Revised: 05/16/2018] [Accepted: 06/04/2018] [Indexed: 10/14/2022]
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20
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Gerlicher AMV, Tüscher O, Kalisch R. Dopamine-dependent prefrontal reactivations explain long-term benefit of fear extinction. Nat Commun 2018; 9:4294. [PMID: 30327462 PMCID: PMC6191435 DOI: 10.1038/s41467-018-06785-y] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 09/26/2018] [Indexed: 12/11/2022] Open
Abstract
Fear extinction does not prevent post-traumatic stress or have long-term therapeutic benefits in fear-related disorders unless extinction memories are easily retrieved at later encounters with the once-threatening stimulus. Previous research in rodents has pointed towards a role for spontaneous prefrontal activity occurring after extinction learning in stabilizing and consolidating extinction memories. In other memory domains spontaneous post-learning activity has been linked to dopamine. Here, we show that a neural activation pattern - evoked in the ventromedial prefrontal cortex (vmPFC) by the unexpected omission of the feared outcome during extinction learning - spontaneously reappears during postextinction rest. The number of spontaneous vmPFC pattern reactivations predicts extinction memory retrieval and vmPFC activation at test 24 h later. Critically, pharmacologically enhancing dopaminergic activity during extinction consolidation amplifies spontaneous vmPFC reactivations and correspondingly improves extinction memory retrieval at test. Hence, a spontaneous dopamine-dependent memory consolidation-based mechanism may underlie the long-term behavioral effects of fear extinction.
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Affiliation(s)
- A M V Gerlicher
- Neuroimaging Center (NIC), Focus Program Translational Neuroscience (FTN), Johannes Gutenberg University Medical Center, Langenbeckstr. 1, 55131, Mainz, Germany.
- Deutsches Resilienz Zentrum (DRZ), Johannes Gutenberg University Medical Center, Untere Zahlbacher Str. 8, 55131, Mainz, Germany.
- Department of Clinical Psychology, University of Amsterdam, Nieuwe Achtergracht 129B, 1018 WS, Amsterdam, The Netherlands.
| | - O Tüscher
- Deutsches Resilienz Zentrum (DRZ), Johannes Gutenberg University Medical Center, Untere Zahlbacher Str. 8, 55131, Mainz, Germany
- Department of Psychiatry and Psychotherapy, Johannes Gutenberg University Medical Center, Untere Zahlbacher Str. 8, 55131, Mainz, Germany
| | - R Kalisch
- Neuroimaging Center (NIC), Focus Program Translational Neuroscience (FTN), Johannes Gutenberg University Medical Center, Langenbeckstr. 1, 55131, Mainz, Germany
- Deutsches Resilienz Zentrum (DRZ), Johannes Gutenberg University Medical Center, Untere Zahlbacher Str. 8, 55131, Mainz, Germany
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21
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Zbukvic IC, Hyun Kim J. Divergent prefrontal dopaminergic mechanisms mediate drug- and fear-associated cue extinction during adolescence versus adulthood. Eur Neuropsychopharmacol 2018; 28:1-12. [PMID: 29174948 DOI: 10.1016/j.euroneuro.2017.11.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 10/08/2017] [Accepted: 11/03/2017] [Indexed: 01/21/2023]
Abstract
Cue-associated learning is vital to guiding behaviour for survival. Adolescence represents a key developmental stage for perturbations in cue-related learning, including a characteristic deficit in cue extinction learning. The present review summarizes evidence from animal and human literature that cue extinction is critically mediated by prefrontal dopamine, a system that undergoes dramatic reorganization during adolescence. We propose that extinction learning and memory is governed by a developmentally dynamic balance of dopamine receptors in the prefrontal cortex, which changes across adolescence into adulthood. This is contrary to the previous idea that extinction deficits during adolescence reflect inefficiency in the same neural circuitry as adults. This leads to proposal of the novel theory that cue extinction involves divergent prefrontal dopaminergic mechanisms depending on the age of extinction.
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Affiliation(s)
- Isabel C Zbukvic
- Black Dog Institute, Randwick 2031, NSW, Australia; Behavioral Neuroscience Division, The Florey Institute of Neuroscience & Mental Health, Parkville 3051, VIC, Australia.
| | - Jee Hyun Kim
- Behavioral Neuroscience Division, The Florey Institute of Neuroscience & Mental Health, Parkville 3051, VIC, Australia; The Florey Department of Neuroscience & Mental Health, University of Melbourne, Parkville 3010, VIC, Australia
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22
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Where There is Smoke There is Fear-Impaired Contextual Inhibition of Conditioned Fear in Smokers. Neuropsychopharmacology 2017; 42:1640-1646. [PMID: 28120933 PMCID: PMC5518897 DOI: 10.1038/npp.2017.17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 11/29/2016] [Accepted: 01/10/2017] [Indexed: 01/19/2023]
Abstract
The odds-ratio of smoking is elevated in populations with neuropsychiatric diseases, in particular in the highly prevalent diagnoses of post-traumatic stress and anxiety disorders. Yet, the association between smoking and a key dimensional phenotype of these disorders-maladaptive deficits in fear learning and fear inhibition-is unclear. We therefore investigated acquisition and memory of fear and fear inhibition in healthy smoking and non-smoking participants (N=349, 22% smokers). We employed a well validated paradigm of context-dependent fear and safety learning (day 1) including a memory retrieval on day 2. During fear learning, a geometrical shape was associated with an aversive electrical stimulation (classical fear conditioning, in danger context) and fear responses were extinguished within another context (extinction learning, in safe context). On day 2, the conditioned stimuli were presented again in both contexts, without any aversive stimulation. Autonomic physiological measurements of skin conductance responses as well as subjective evaluations of fear and expectancy of the aversive stimulation were acquired. We found that impairment of fear inhibition (extinction) in the safe context during learning (day 1) was associated with the amount of pack-years in smokers. During retrieval of fear memories (day 2), smokers showed an impairment of contextual (safety context-related) fear inhibition as compared with non-smokers. These effects were found in physiological as well as subjective measures of fear. We provide initial evidence that smokers as compared with non-smokers show an impairment of fear inhibition. We propose that smokers have a deficit in integrating contextual signs of safety, which is a hallmark of post-traumatic stress and anxiety disorders.
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Abstract
Anxiety disorders are among the most prevalent and disabling psychiatric disorders. Patients and their families have a plethora of evidence-based treatment options to manage these potentially incapacitating and costly disorders. Nurses in various settings can assess symptoms of anxiety disorder and initiate or refer patients for treatment. Families play a critical role in treatment planning and must be part of the health care team. Primary nursing interventions must be person centered and recovery based to ensure accurate diagnosis, initiation of appropriate person-centered treatment, and facilitate an optimal level of functioning and quality of life.
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Affiliation(s)
- Deborah Antai-Otong
- Department of Veterans Affairs, Veterans Integrated Service Networks-(VISN-17), 2301 E. Lamar Boulevard, Arlington, TX 76006, USA.
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24
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Jung YP, Earnest CP, Koozehchian M, Galvan E, Dalton R, Walker D, Rasmussen C, Murano PS, Greenwood M, Kreider RB. Effects of acute ingestion of a pre-workout dietary supplement with and without p-synephrine on resting energy expenditure, cognitive function and exercise performance. J Int Soc Sports Nutr 2017; 14:3. [PMID: 28096758 PMCID: PMC5234109 DOI: 10.1186/s12970-016-0159-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 12/16/2016] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The purpose of this study was to examine the effects of acute ingestion of a pre-workout dietary supplement (PWS) with and without p-synephrine (S) on perceptions of readiness to perform, cognitive function, exercise performance, and markers of safety. METHODS In a randomized, double-blind, and counterbalanced manner; 25 healthy and recreationally active male and female participants ingested a flavored maltodextrin placebo (PLA), a PWS containing beta-alanine (3 g), creatine nitrate as a salt (2 g), arginine alpha-ketoglutarate (2 g), N-Acetyl-L-Tyrosine (300 mg), caffeine (284 mg), Mucuna pruiriens extract standardized for 15% L-Dopa (15 mg), Vitamin C as Ascorbic Acid (500 mg), niacin (60 mg), folate as folic acid (50 mg), and Vitamin B12 as Methylcobalamin (70 mg) with 2 g of maltodextrin and flavoring; or, the PWS with Citrus aurantium (PWS + S) extract standardized for 30% p-synephrine (20 mg). Participants had heart rate (HR), blood pressure, resting energy expenditure (REE), 12-lead electrocardiograms (ECG), perceptions about readiness to perform, cognitive function (Stroop Color-Word test), bench and leg press performance (2 sets of 10 repetitions at 70% of 1RM and 1 set to failure), and Wingate anaerobic capacity (WAC) sprint performance determined as well as donated blood samples prior to and/or following exercise/supplementation. Data were analyzed by MANOVA with repeated measures as well as mean changes from baseline with 95% confidence intervals (CI). RESULTS No clinically significant differences were observed among treatments in HR, blood pressure, ECG, or general clinical blood panels. There was evidence that PWS and PWS + S ingestion promoted greater changes in REE responses. Participants reported higher perception of optimism about performance and vigor and energy with PWS and PWS + S ingestion and there was evidence that PWS and PWS + S improved changes in cognitive function scores from baseline to a greater degree than PLA after 1 or 2 h. However, the scores in the PWS + S treatment did not exceed PLA or PWS responses at any data point. No statistically significant differences were observed among treatments in total bench press lifting volume, leg press lifting volume or WAC sprint performance. CONCLUSIONS Within the confines of this study, ingestion of PWS and/or PWS + S prior to exercise appears to be well-tolerated when consumed by young, healthy individuals. The primary effects appear to be to increase REE responses and improve perceptions about readiness to perform and cognitive function with limited to no effects on muscular endurance and WAC. The addition of 20 mg of p-synephrine to the PWS provided limited to no additive benefits. TRIAL REGISTRATION This trial (NCT02952014) was retrospectively registered on September 13th 2016.
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Affiliation(s)
- Y. Peter Jung
- Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA
| | - Conrad P. Earnest
- Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA
- Nutrabolt, Bryan, TX 77807 USA
| | - Majid Koozehchian
- Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA
| | - Elfego Galvan
- Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA
| | - Ryan Dalton
- Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA
| | - Dillon Walker
- Center for Translational Research in Aging and Longevity, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA
| | - Christopher Rasmussen
- Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA
| | - Peter S. Murano
- Institute for Obesity Research & Program Evaluation, Department of Nutrition and Food Sciences, Texas A&M University, College Station, TX 77843 USA
| | - Mike Greenwood
- Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA
| | - Richard B. Kreider
- Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA
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25
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Jung YP, Earnest CP, Koozehchian M, Cho M, Barringer N, Walker D, Rasmussen C, Greenwood M, Murano PS, Kreider RB. Effects of ingesting a pre-workout dietary supplement with and without synephrine for 8 weeks on training adaptations in resistance-trained males. J Int Soc Sports Nutr 2017; 14:1. [PMID: 28096757 PMCID: PMC5234097 DOI: 10.1186/s12970-016-0158-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Accepted: 12/12/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The purpose of this study was to examine whether ingesting a pre-workout dietary supplement (PWS) with and without synephrine (S) during training affects training responses in resistance-trained males. METHODS Resistance-trained males (N = 80) were randomly assigned to supplement their diet in a double-blind manner with either a flavored placebo (PLA); a PWS containing beta-alanine (3 g), creatine nitrate as a salt (2 g), arginine alpha-ketoglutarate (2 g), N-Acetyl-L-Tyrosine (300 mg), caffeine (284 mg), Mucuna pruiriens extract standardized for 15% L-Dopa (15 mg), Vitamin C as Ascorbic Acid (500 mg), niacin (60 mg), folate as folic acid (50 mg), and Vitamin B12 as Methylcobalamin (70 mg); or, the PWS supplement with Citrus aurantium extract containing 20 mg of synephrine (PWS + S) once per day for 8-weeks during training. Participants donated a fasting blood sample and had body composition (DXA), resting heart rate and blood pressure, cognitive function (Stroop Test), readiness to perform, bench and leg press 1 RM, and Wingate anaerobic capacity assessments determined a 0, 4, and 8-weeks of standardized training. Data were analyzed by MANOVA with repeated measures. Performance and cognitive function data were analyzed using baseline values as covariates as well as mean changes from baseline with 95% confidence intervals (CI). Blood chemistry data were also analyzed using Chi-square analysis. RESULTS Although significant time effects were seen, no statistically significant overall MANOVA Wilks' Lambda interactions were observed among groups for body composition, resting heart and blood pressure, readiness to perform questions, 1RM strength, anaerobic sprint capacity, or blood chemistry panels. MANOVA univariate analysis and analysis of changes from baseline with 95% CI revealed some evidence that cognitive function and 1RM strength were increased to a greater degree in the PWS and/or PWS + S groups after 4- and/or 8-weeks compared to PLA responses. However, there was no evidence that PWS + S promoted greater overall training adaptations compared to the PWS group. Dietary supplementation of PWS and PWS + S did not increase the incidence of reported side effects or significantly affect the number of blood values above clinical norms compared to PLA. CONCLUSION Results provide some evidence that 4-weeks of PWS and/or PWS + S supplementation can improve some indices of cognitive function and exercise performance during resistance-training without significant side effects in apparently health males. However, these effects were similar to PLA responses after 8-weeks of supplementation and inclusion of synephrine did not promote additive benefits. TRIAL REGISTRATION This trial (NCT02999581) was retrospectively registered on December 16th 2016.
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Affiliation(s)
- Y. Peter Jung
- Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA
| | - Conrad P. Earnest
- Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA
- Nutrabolt, Bryan, TX 77807 USA
| | - Majid Koozehchian
- Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA
| | - Minye Cho
- Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA
| | - Nick Barringer
- Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA
| | - Dillon Walker
- Department of Health & Kinesiology, Center for Translational Research in Aging and Longevity, Texas A&M University, College Station, TX 77843-4243 USA
| | - Christopher Rasmussen
- Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA
| | - Mike Greenwood
- Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA
| | - Peter S. Murano
- Department of Nutrition and Food Sciences, Institute for Obesity Research & Program Evaluation, Texas A&M University, College Station, TX 77843 USA
| | - Richard B. Kreider
- Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA
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Stockhorst U, Antov MI. Modulation of Fear Extinction by Stress, Stress Hormones and Estradiol: A Review. Front Behav Neurosci 2016; 9:359. [PMID: 26858616 PMCID: PMC4726806 DOI: 10.3389/fnbeh.2015.00359] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 12/14/2015] [Indexed: 12/25/2022] Open
Abstract
Fear acquisition and extinction are valid models for the etiology and treatment of anxiety, trauma- and stressor-related disorders. These disorders are assumed to involve aversive learning under acute and/or chronic stress. Importantly, fear conditioning and stress share common neuronal circuits. The stress response involves multiple changes interacting in a time-dependent manner: (a) the fast first-wave stress response [with central actions of noradrenaline, dopamine, serotonin, corticotropin-releasing hormone (CRH), plus increased sympathetic tone and peripheral catecholamine release] and (b) the second-wave stress response [with peripheral release of glucocorticoids (GCs) after activation of the hypothalamus-pituitary-adrenocortical (HPA) axis]. Control of fear during extinction is also sensitive to these stress-response mediators. In the present review, we will thus examine current animal and human data, addressing the role of stress and single stress-response mediators for successful acquisition, consolidation and recall of fear extinction. We report studies using pharmacological manipulations targeting a number of stress-related neurotransmitters and neuromodulators [monoamines, opioids, endocannabinoids (eCBs), neuropeptide Y, oxytocin, GCs] and behavioral stress induction. As anxiety, trauma- and stressor-related disorders are more common in women, recent research focuses on female sex hormones and identifies a potential role for estradiol in fear extinction. We will thus summarize animal and human data on the role of estradiol and explore possible interactions with stress or stress-response mediators in extinction. This also aims at identifying time-windows of enhanced (or reduced) sensitivity for fear extinction, and thus also for successful exposure therapy.
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Affiliation(s)
- Ursula Stockhorst
- Experimental Psychology II and Biological Psychology, Institute of Psychology, University of OsnabrückOsnabrück, Germany
| | - Martin I. Antov
- Experimental Psychology II and Biological Psychology, Institute of Psychology, University of OsnabrückOsnabrück, Germany
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