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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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2
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Abstract
Twenty-two years after their discovery, the hypocretins (Hcrts), also known as orexins, are two of the most studied peptidergic systems, involved in myriad physiological systems that range from sleep, arousal, motivation, homeostatic regulation, fear, anxiety and learning. A causal relationship between activity of Hcrt and arousal stability was established shortly after their discovery and have led to the development of a new class of drugs to treat insomnia. In this review we discuss the many faces of the Hcrt system and examine recent findings that implicate decreased Hcrt function in the pathogenesis of a number of neuropsychiatric conditions. We also discuss future therapeutic strategies to replace or enhance Hcrt function as a treatment option for these neuropsychiatric conditions.
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Affiliation(s)
- Erica Seigneur
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA
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3
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Stone LA, Girgenti MJ, Wang J, Ji D, Zhao H, Krystal JH, Duman RS. Cortical Transcriptomic Alterations in Association With Appetitive Neuropeptides and Body Mass Index in Posttraumatic Stress Disorder. Int J Neuropsychopharmacol 2020; 24:118-129. [PMID: 32951025 PMCID: PMC8611677 DOI: 10.1093/ijnp/pyaa072] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 08/10/2020] [Accepted: 09/17/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The molecular pathology underlying posttraumatic stress disorder (PTSD) remains unclear mainly due to a lack of human PTSD postmortem brain tissue. The orexigenic neuropeptides ghrelin, neuropeptide Y, and hypocretin were recently implicated in modulating negative affect. Drawing from the largest functional genomics study of human PTSD postmortem tissue, we investigated whether there were molecular changes of these and other appetitive molecules. Further, we explored the interaction between PTSD and body mass index (BMI) on gene expression. METHODS We analyzed previously reported transcriptomic data from 4 prefrontal cortex regions from 52 individuals with PTSD and 46 matched neurotypical controls. We employed gene co-expression network analysis across the transcriptomes of these regions to uncover PTSD-specific networks containing orexigenic genes. We utilized Ingenuity Pathway Analysis software for pathway annotation. We identified differentially expressed genes (DEGs) among individuals with and without PTSD, stratified by sex and BMI. RESULTS Three PTSD-associated networks (P < .01) contained genes in signaling families of appetitive molecules: 2 in females and 1 in all subjects. We uncovered DEGs (P < .05) between PTSD and control subjects stratified by sex and BMI with especially robust changes in males with PTSD with elevated vs normal BMI. Further, we identified putative upstream regulators (P < .05) driving these changes, many of which were enriched for involvement in inflammation. CONCLUSIONS PTSD-associated cortical transcriptomic modules contain transcripts of appetitive genes, and BMI further interacts with PTSD to impact expression. DEGs and inferred upstream regulators of these modules could represent targets for future pharmacotherapies for obesity in PTSD.
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Affiliation(s)
- Lauren A Stone
- Department of Psychiatry, Yale School of Medicine, New Haven,
CT,Clinical Neuroscience Division, National Center for PTSD and National PTSD
Brain Bank VA Connecticut Healthcare System, West Haven, CT
| | - Matthew J Girgenti
- Department of Psychiatry, Yale School of Medicine, New Haven,
CT,Clinical Neuroscience Division, National Center for PTSD and National PTSD
Brain Bank VA Connecticut Healthcare System, West Haven, CT,Correspondence: Matthew J. Girgenti, PhD, Abraham Ribicoff Research
Laboratories, Connecticut Mental Health Center, 34 Park St, New Haven, CT 06510 ()
| | - Jiawei Wang
- Program of Computational Biology and Bioinformatics, Yale
University, New Haven, CT
| | - Dingjue Ji
- Program of Computational Biology and Bioinformatics, Yale
University, New Haven, CT
| | - Hongyu Zhao
- Program of Computational Biology and Bioinformatics, Yale
University, New Haven, CT,Department of Biostatistics, Yale School of Public Health, New
Haven, CT
| | - John H Krystal
- Department of Psychiatry, Yale School of Medicine, New Haven,
CT,Clinical Neuroscience Division, National Center for PTSD and National PTSD
Brain Bank VA Connecticut Healthcare System, West Haven, CT,Departments of Neuroscience and Psychology, and the Yale Center for Clinical
Investigation, Yale University, New Haven, CT,Department of Psychiatry, Yale New Haven Health System, New
Haven, CT
| | - Ronald S Duman
- Department of Psychiatry, Yale School of Medicine, New Haven,
CT,Clinical Neuroscience Division, National Center for PTSD and National PTSD
Brain Bank VA Connecticut Healthcare System, West Haven, CT
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Significance of the orexinergic system in modulating stress-related responses in an animal model of post-traumatic stress disorder. Transl Psychiatry 2020; 10:10. [PMID: 32066707 PMCID: PMC7026175 DOI: 10.1038/s41398-020-0698-9] [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: 02/07/2019] [Revised: 10/02/2019] [Accepted: 10/20/2019] [Indexed: 01/23/2023] Open
Abstract
Converging evidence indicates that orexins (ORXs), the regulatory neuropeptides, are implicated in anxiety- and depression-related behaviors via the modulation of neuroendocrine, serotonergic, and noradrenergic systems. This study evaluated the role of the orexinergic system in stress-associated physiological responses in a controlled prospective animal model. The pattern and time course of activation of hypothalamic ORX neurons in response to predator-scent stress (PSS) were examined using c-Fos as a marker for neuronal activity. The relationship between the behavioral response pattern 7 days post-exposure and expressions of ORXs was evaluated. We also investigated the effects of intracerebroventricular microinfusion of ORX-A or almorexant (ORX-A/B receptor antagonist) on behavioral responses 7 days following PSS exposure. Hypothalamic levels of ORX-A, neuropeptide Y (NPY), and brain-derived neurotrophic factor (BDNF) were assessed. Compared with rats whose behaviors were extremely disrupted (post-traumatic stress disorder [PTSD]-phenotype), those whose behaviors were minimally selectively disrupted displayed significantly upregulated ORX-A and ORX-B levels in the hypothalamic nuclei. Intracerebroventricular microinfusion of ORX-A before PSS reduced the prevalence of the PTSD phenotype compared with that of artificial cerebrospinal fluid or almorexant, and rats treated with almorexant displayed a higher prevalence of the PTSD phenotype than did untreated rats. Activated ORX neurons led to upregulated expressions of BDNF and NPY, which might provide an additional regulatory mechanism for the modulation of adaptive stress responses. The study indicates that the activated ORX system might promote adaptive responses to PSS probably via stimulation of BDNF and NPY secretion, and early intervention with ORX-A reduces the prevalence of the PTSD phenotype and increases the prevalence of adaptive phenotypes. The findings provide some insights into the mechanisms underlying the involvement of the ORX system in stress-related disorders.
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Wilson MA, Liberzon I, Lindsey ML, Lokshina Y, Risbrough VB, Sah R, Wood SK, Williamson JB, Spinale FG. Common pathways and communication between the brain and heart: connecting post-traumatic stress disorder and heart failure. Stress 2019; 22:530-547. [PMID: 31161843 PMCID: PMC6690762 DOI: 10.1080/10253890.2019.1621283] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Psychiatric illnesses and cardiovascular disease (CVD) contribute to significant overall morbidity, mortality, and health care costs, and are predicted to reach epidemic proportions with the aging population. Within the Veterans Administration (VA) health care system, psychiatric illnesses such as post-traumatic stress disorder (PTSD) and CVD such as heart failure (HF), are leading causes of hospital admissions, prolonged hospital stays, and resource utilization. Numerous studies have demonstrated associations between PTSD symptoms and CVD endpoints, particularly in the Veteran population. Not only does PTSD increase the risk of HF, but this relationship is bi-directional. Accordingly, a VA-sponsored conference entitled "Cardiovascular Comorbidities in PTSD: The Brain-Heart Consortium" was convened to explore potential relationships and common biological pathways between PTSD and HF. The conference was framed around the hypothesis that specific common systems are dysregulated in both PTSD and HF, resulting in a synergistic acceleration and amplification of both disease processes. The conference was not intended to identify all independent pathways that give rise to PTSD and HF, but rather identify shared systems, pathways, and biological mediators that would be modifiable in both disease processes. The results from this conference identified specific endocrine, autonomic, immune, structural, genetic, and physiological changes that may contribute to shared PTSD-CVD pathophysiology and could represent unique opportunities to develop therapies for both PTSD and HF. Some recommendations from the group for future research opportunities are provided.
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Affiliation(s)
- Marlene A. Wilson
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine and Research Service, Columbia VA Health Care System, Columbia SC
- Corresponding author information: Marlene A. Wilson, Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia SC 29208, Research Service, Columbia VA Health Care System, Columbia SC 29209, ; 803-216-3507
| | - Israel Liberzon
- Department of Psychiatry, Texas A&M College of Medicine, Bryan, TX
| | - Merry L. Lindsey
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, and Research Service, Omaha VA Medical Center, Omaha NE
| | - Yana Lokshina
- Department of Psychiatry, Texas A&M College of Medicine, Bryan, TX
| | - Victoria B. Risbrough
- VA Center of Excellence for Stress and Mental Health, La Jolla CA, Dept. of Psychiatry, University of California San Diego
| | - Renu Sah
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH
| | - Susan K. Wood
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine and Research Service, Columbia VA Health Care System, Columbia SC
| | - John B. Williamson
- Department of Neurology, University of Florida College of Medicine, Gainesville FL
| | - Francis G. Spinale
- Department of Cell Biology and Anatomy, University of South Carolina School of Medicine and Research Service, Columbia VA Health Care System., Columbia SC
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Nwokafor C, Serova LI, Sabban EL. Preclinical findings on the potential of intranasal neuropeptide Y for treating hyperarousal features of PTSD. Ann N Y Acad Sci 2019; 1455:149-159. [PMID: 31250475 DOI: 10.1111/nyas.14172] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 05/20/2019] [Accepted: 05/29/2019] [Indexed: 01/10/2023]
Abstract
Acoustic startle response (ASR) assesses hyperarousal, a core symptom of posttraumatic stress disorder (PTSD). Intranasal neuropeptide Y (NPY) administration was shown to prevent hyperarousal in single prolonged stress (SPS) rodent PTSD model. However, it is unclear how ASR itself alters responses to stress. Rats (A-S-A) were exposed to acoustic startle (AS) 1 day before SPS (ASR1) and 2 weeks afterward (ASR2). Other groups were exposed in parallel to either AS (A-A) or SPS or neither. SPS enhanced ASR2. In relevant brain areas, mRNA levels were determined by qRT-PCR. In mediobasal hypothalamus, AS or SPS each increased CRH mRNA levels without an additive effect. Exposure to AS appeared to dampen some responses to SPS. The SPS-triggered reduction of GR and FKBP5 gene expression was not observed in A-S-A group. In locus coeruleus, SPS increased CRHR1 and reduced Y2R mRNAs, but not in A-S-A group. In both regions, AS altered NPY receptor gene expression, which may mediate dampening responses to SPS. In second experiment, intranasal NPY administered 2 weeks after SPS reversed hyperarousal symptoms for at least 7 days. This study reveals important effects of AS on the NPY system and demonstrates that intranasal NPY elicits long-lasting reversal of traumatic stress-triggered hyperarousal.
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Affiliation(s)
- Chiso Nwokafor
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York
| | - Lidia I Serova
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York
| | - Esther L Sabban
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York
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Malikowska-Racia N, Sałat K, Nowaczyk A, Fijałkowski Ł, Popik P. Dopamine D2/D3 receptor agonists attenuate PTSD-like symptoms in mice exposed to single prolonged stress. Neuropharmacology 2019; 155:1-9. [PMID: 31085186 DOI: 10.1016/j.neuropharm.2019.05.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 04/28/2019] [Accepted: 05/09/2019] [Indexed: 01/19/2023]
Abstract
Medications that enhance dopaminergic neurotransmission can be useful in the pharmacotherapy of posttraumatic stress disorder (PTSD), which manifests as fearful memory retrieval, anxiety and depression. We examined the effects of subchronic (15 days) treatment with select dopaminergic medications, including bromocriptine, modafinil, dihydrexidine, rotigotine and pramipexole, in a mouse model of PTSD induced by single prolonged stress (mSPS). The potential antidepressant-like and anxiolytic effects of the medications were measured by the forced swim test (FST) and the elevated plus maze (EPM) test, respectively. In addition, we studied the effects of these medications on memory retrieval in an auditory fear conditioning (FC) test, on ultrasonic vocalizations (USVs) induced by restraint stress, and on spontaneous locomotor activity (SLA). We report that a single exposure to a severe and complex set of stressors several days before testing increased immobility time in the FST and freezing in the FC paradigm and reduced the time spent in the open arms of the EPM. The stressed mice also displayed increased USVs, especially the short type. While none of the tested dopamine-mimetics exhibited anxiolytic-like effects, rotigotine produced antidepressant-like activity specifically in the mSPS-exposed animals. Moreover, both rotigotine and pramipexole shortened the duration of freezing in the fear conditioning test, but only in the mSPS-exposed mice. This study supports the hypothesis that the activation of dopaminergic D2/D3 receptors may be a promising pharmacotherapy for PTSD.
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Affiliation(s)
- Natalia Malikowska-Racia
- Department of Pharmacodynamics, Chair of Pharmacodynamics, Jagiellonian University Medical College, 9 Medyczna St., 30-688, Krakow, Poland.
| | - Kinga Sałat
- Department of Pharmacodynamics, Chair of Pharmacodynamics, Jagiellonian University Medical College, 9 Medyczna St., 30-688, Krakow, Poland
| | - Alicja Nowaczyk
- Department of Organic Chemistry, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, 2 dr. A. Jurasza St., 85-094, Bydgoszcz, Poland
| | - Łukasz Fijałkowski
- Department of Organic Chemistry, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, 2 dr. A. Jurasza St., 85-094, Bydgoszcz, Poland
| | - Piotr Popik
- Faculty of Health Sciences, Jagiellonian University Medical College, 12 Michalowskiego St., 31-126, Krakow, Poland; Behavioral Neuroscience and Drug Development, Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna St., 31-343, Krakow, Poland
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Nevárez N, de Lecea L. Recent advances in understanding the roles of hypocretin/orexin in arousal, affect, and motivation. F1000Res 2018; 7. [PMID: 30254737 PMCID: PMC6127742 DOI: 10.12688/f1000research.15097.1] [Citation(s) in RCA: 33] [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] [Accepted: 08/24/2018] [Indexed: 12/11/2022] Open
Abstract
The hypocretins (Hcrts) are two alternatively spliced neuropeptides (Hcrt1/Ox-A and Hcrt2/Ox-B) that are synthesized exclusively in the hypothalamus. Data collected in the 20 years since their discovery have supported the view that the Hcrts play a broad role in the control of arousal with a particularly important role in the maintenance of wakefulness and sleep-to-wake transitions. While this latter point has received an overwhelming amount of research attention, a growing literature has begun to broaden our understanding of the many diverse roles that the Hcrts play in physiology and behavior. Here, we review recent advances in the neurobiology of Hcrt in three sections. We begin by surveying findings on Hcrt function within normal sleep/wake states as well as situations of aberrant sleep (that is, narcolepsy). In the second section, we discuss research establishing a role for Hcrt in mood and affect (that is, anxiety, stress, and motivation). Finally, in the third section, we briefly discuss future directions for the field and place an emphasis on analytical modeling of Hcrt neural activity. We hope that the data discussed here provide a broad overview of recent progress in the field and make clear the diversity of roles played by these neuromodulators.
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Affiliation(s)
- Natalie Nevárez
- Department of Psychiatry & Behavioral Sciences, Stanford University, Stanford, California, USA
| | - Luis de Lecea
- Department of Psychiatry & Behavioral Sciences, Stanford University, Stanford, California, USA
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Cohen H, Zohar J, Kaplan Z, Arnt J. Adjunctive treatment with brexpiprazole and escitalopram reduces behavioral stress responses and increase hypothalamic NPY immunoreactivity in a rat model of PTSD-like symptoms. Eur Neuropsychopharmacol 2018; 28:63-74. [PMID: 29224968 DOI: 10.1016/j.euroneuro.2017.11.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Revised: 10/19/2017] [Accepted: 11/23/2017] [Indexed: 10/18/2022]
Abstract
The study explored effects of brexpiprazole (partial D2/5-HT1A agonist, 5-HT2A and α1B/2C-adrenoceptor antagonist) in rats exposed to predator scent stress (PSS), a proposed model of PTSD-like phenotype. Brexpiprazole (3.0mg/kg, PO), escitalopram (5.0mg/kg, IP) and their combination were administered twice daily for 14 days, starting 14 days after exposure to PSS or sham-PSS, shortly after a situational stress reminder. One day after last treatment behavioral responsivity was assessed. Brexpiprazole+escitalopram-treated rats spent more time in open arms, entered open arms more often and exhibited a lower anxiety index in the elevated plus maze than vehicle-treated, PSS-exposed rats. Adjunct brexpiprazole+escitalopram treatment reduced startle amplitude, compared with vehicle-treated, PSS-exposed rats. Treatment with either drug alone did not attenuate anxiety-like behaviors following PSS exposure. Use of cut-off behavioral criteria confirmed that adjunct treatment shifted prevalence of PSS-exposed rats from extreme towards minimal behavioral responders. One day following behavioral tests, brains were prepared for immunohistochemical analysis of number of BDNF-positive cells and of NPY-positive cells/fibers. PSS exposure decreased BDNF levels in hippocampus, but this was not affected by drug treatments. PSS exposure decreased number of NPY positive cells/fibers in paraventricular and arcuate nuclei of hypothalamus. Adjunct treatment with brexpiprazole+escitalopram increased NPY in PSS- and sham-exposed rats. Treatment with brexpiprazole alone had no effects, while treatment with escitalopram alone increased NPY in the arcuate nucleus of PSS-exposed rats. In conclusion, treatment with brexpiprazole+escitalopram may be an effective intervention for the attenuation of PTSD-like stress responses, which in part may be mediated by activating NPY function.
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Affiliation(s)
- Hagit Cohen
- Anxiety and Stress Research Unit, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Joseph Zohar
- The Chaim Sheba Medical Center, Sackler Medical School, Tel-Aviv University, Tel Hashomer, Israel
| | - Zeev Kaplan
- Anxiety and Stress Research Unit, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Jørn Arnt
- Synaptic Transmission, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Valby, Denmark; Sunred Pharma Consulting ApS, Svend Gonges Vej 11A, DK-2680 Solrod Strand, Denmark.
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