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Avgana H, Toledano RS, Akirav I. Examining the Role of Oxytocinergic Signaling and Neuroinflammatory Markers in the Therapeutic Effects of MDMA in a Rat Model for PTSD. Pharmaceuticals (Basel) 2024; 17:846. [PMID: 39065697 PMCID: PMC11279644 DOI: 10.3390/ph17070846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Revised: 06/20/2024] [Accepted: 06/25/2024] [Indexed: 07/28/2024] Open
Abstract
MDMA-assisted psychotherapy has shown potential as an effective treatment for post-traumatic stress disorder (PTSD). Preclinical studies involving rodents have demonstrated that MDMA can facilitate the extinction of fear memories. It has been noted that MDMA impacts oxytocin neurons and pro-inflammatory cytokines. Thus, the aim of this study was to explore the role of oxytocinergic signaling and neuroinflammatory markers in the therapeutic effects of MDMA. To achieve this, male rats were subjected to a model of PTSD involving exposure to shock and situational reminders. MDMA was microinjected into the medial prefrontal cortex (mPFC) before extinction training, followed by behavioral tests assessing activity levels, anxiety, and social function. Our findings indicate that MDMA treatment facilitated fear extinction and mitigated the shock-induced increase in freezing, as well as deficits in social behavior. Shock exposure led to altered expression of the gene coding for OXT-R and neuroinflammation in the mPFC and basolateral amygdala (BLA), which were restored by MDMA treatment. Importantly, the OXT-R antagonist L-368,899 prevented MDMA's therapeutic effects on extinction and freezing behavior. In conclusion, MDMA's therapeutic effects in the PTSD model are associated with alterations in OXT-R expression and neuroinflammation, and MDMA's effects on extinction and anxiety may be mediated by oxytocinergic signaling.
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Affiliation(s)
- Haron Avgana
- Department of Psychology, School of Psychological Sciences, University of Haifa, Haifa 3498838, Israel; (H.A.); (R.S.T.)
- The Integrated Brain and Behavior Research Center (IBBRC), University of Haifa, Haifa 3498838, Israel
| | - Roni Shira Toledano
- Department of Psychology, School of Psychological Sciences, University of Haifa, Haifa 3498838, Israel; (H.A.); (R.S.T.)
- The Integrated Brain and Behavior Research Center (IBBRC), University of Haifa, Haifa 3498838, Israel
| | - Irit Akirav
- Department of Psychology, School of Psychological Sciences, University of Haifa, Haifa 3498838, Israel; (H.A.); (R.S.T.)
- The Integrated Brain and Behavior Research Center (IBBRC), University of Haifa, Haifa 3498838, Israel
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2
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Sherman ER, Li J, Cahill EN. No impairment of contextual fear memory consolidation by oxytocin receptor antagonism in male rats. Physiol Behav 2024; 279:114545. [PMID: 38580203 DOI: 10.1016/j.physbeh.2024.114545] [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: 12/21/2023] [Revised: 03/11/2024] [Accepted: 04/02/2024] [Indexed: 04/07/2024]
Abstract
Oxytocin is a peptide released into brain regions associated with the processing of aversive memory and threat responses. Given the expression of oxytocin receptors across this vigilance surveillance system of the brain, we investigated whether pharmacological antagonism of the receptor would impact contextual aversive conditioning and memory. Adult male rats were conditioned to form an aversive contextual memory. The effects of peripheral administration of either the competitive antagonist Atosiban or noncompetitive antagonist L-368,899 were compared to saline controls. Oxytocin receptor antagonism treatment did not significantly impact the consolidation of aversive contextual memory in any of the groups. We conclude that peripheral antagonism of oxytocin signalling did not impact the formation of aversive memory.
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Affiliation(s)
- Emily R Sherman
- Department of Physiology, Development, and Neuroscience, University of Cambridge, CB2 3EB, UK
| | - Jialu Li
- Bristol Medical School, University of Bristol, BS8 1TH, UK
| | - Emma N Cahill
- Department of Physiology, Development, and Neuroscience, University of Cambridge, CB2 3EB, UK; School of Physiology, Pharmacology and Neuroscience, University of Bristol, BS8 1TD, UK.
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3
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Vörös D, Kiss O, Taigiszer M, László BR, Ollmann T, Péczely L, Zagorácz O, Kertes E, Kállai V, Berta B, Kovács A, Karádi Z, Lénárd L, László K. The role of intraamygdaloid oxytocin in spatial learning and avoidance learning. Peptides 2024; 175:171169. [PMID: 38340898 DOI: 10.1016/j.peptides.2024.171169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/26/2024] [Accepted: 02/06/2024] [Indexed: 02/12/2024]
Abstract
The goal of the present study is to investigate the role of intraamygdaloid oxytocin in learning-related mechanisms. Oxytocin is a neuropeptide which is involved in social bonding, trust, emotional responses and various social behaviors. By conducting passive avoidance and Morris water maze tests on male Wistar rats, the role of intraamygdaloid oxytocin in memory performance and learning was investigated. Oxytocin doses of 10 ng and 100 ng were injected into the central nucleus of the amygdala. Our results showed that 10 ng oxytocin significantly reduced the time required to locate the platform during the Morris water maze test while significantly increasing the latency time in the passive avoidance test. However, the 100 ng oxytocin experiment failed to produce a significant effect in either of the tests. Wistar rats pretreated with 20 ng oxytocin receptor antagonist (L-2540) were administered 10 ng of oxytocin into the central nucleus of the amygdala and were also subjected to the aforementioned tests to highlight the role of oxytocin receptors in spatial- and avoidance learning. Results suggest that oxytocin supports memory processing during both the passive avoidance and the Morris water maze tests. Oxytocin antagonists can however block the effects of oxytocin in both tests. The results substantiate that oxytocin uses oxytocin receptors to enhance memory and learning performance.
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Affiliation(s)
- Dávid Vörös
- Medical School, Institute of Physiology, University of Pécs, Szigeti Str. 12, P.O. Box 99, 7602 Pécs, Hungary; Neuropeptides, Cognition, Animal Models of Neuropsychiatric Disorders Research Group, Medical School, Institute of Physiology, University of Pécs, 7602 Pécs, Hungary
| | - Orsolya Kiss
- Medical School, Institute of Physiology, University of Pécs, Szigeti Str. 12, P.O. Box 99, 7602 Pécs, Hungary; Neuropeptides, Cognition, Animal Models of Neuropsychiatric Disorders Research Group, Medical School, Institute of Physiology, University of Pécs, 7602 Pécs, Hungary
| | - Márton Taigiszer
- Medical School, Institute of Physiology, University of Pécs, Szigeti Str. 12, P.O. Box 99, 7602 Pécs, Hungary; Neuropeptides, Cognition, Animal Models of Neuropsychiatric Disorders Research Group, Medical School, Institute of Physiology, University of Pécs, 7602 Pécs, Hungary
| | - Bettina Réka László
- Medical School, Institute of Physiology, University of Pécs, Szigeti Str. 12, P.O. Box 99, 7602 Pécs, Hungary; Neuroscience Center, University of Pécs, 7602 Pécs, Hungary
| | - Tamás Ollmann
- Medical School, Institute of Physiology, University of Pécs, Szigeti Str. 12, P.O. Box 99, 7602 Pécs, Hungary; Neuropeptides, Cognition, Animal Models of Neuropsychiatric Disorders Research Group, Medical School, Institute of Physiology, University of Pécs, 7602 Pécs, Hungary; Neuroscience Center, University of Pécs, 7602 Pécs, Hungary; Learning in Biological and Artificial Systems Research Group, Medical School, Institute of Physiology, University of Pécs, 7602 Pécs, Hungary
| | - László Péczely
- Medical School, Institute of Physiology, University of Pécs, Szigeti Str. 12, P.O. Box 99, 7602 Pécs, Hungary; Neuroscience Center, University of Pécs, 7602 Pécs, Hungary; Learning in Biological and Artificial Systems Research Group, Medical School, Institute of Physiology, University of Pécs, 7602 Pécs, Hungary
| | - Olga Zagorácz
- Medical School, Institute of Physiology, University of Pécs, Szigeti Str. 12, P.O. Box 99, 7602 Pécs, Hungary; Neuropeptides, Cognition, Animal Models of Neuropsychiatric Disorders Research Group, Medical School, Institute of Physiology, University of Pécs, 7602 Pécs, Hungary; Neuroscience Center, University of Pécs, 7602 Pécs, Hungary; Learning in Biological and Artificial Systems Research Group, Medical School, Institute of Physiology, University of Pécs, 7602 Pécs, Hungary
| | - Erika Kertes
- Medical School, Institute of Physiology, University of Pécs, Szigeti Str. 12, P.O. Box 99, 7602 Pécs, Hungary; Neuropeptides, Cognition, Animal Models of Neuropsychiatric Disorders Research Group, Medical School, Institute of Physiology, University of Pécs, 7602 Pécs, Hungary; Neuroscience Center, University of Pécs, 7602 Pécs, Hungary; Learning in Biological and Artificial Systems Research Group, Medical School, Institute of Physiology, University of Pécs, 7602 Pécs, Hungary
| | - Veronika Kállai
- Medical School, Institute of Physiology, University of Pécs, Szigeti Str. 12, P.O. Box 99, 7602 Pécs, Hungary; Neuropeptides, Cognition, Animal Models of Neuropsychiatric Disorders Research Group, Medical School, Institute of Physiology, University of Pécs, 7602 Pécs, Hungary; Neuroscience Center, University of Pécs, 7602 Pécs, Hungary; Learning in Biological and Artificial Systems Research Group, Medical School, Institute of Physiology, University of Pécs, 7602 Pécs, Hungary
| | - Beáta Berta
- Medical School, Institute of Physiology, University of Pécs, Szigeti Str. 12, P.O. Box 99, 7602 Pécs, Hungary; Neuropeptides, Cognition, Animal Models of Neuropsychiatric Disorders Research Group, Medical School, Institute of Physiology, University of Pécs, 7602 Pécs, Hungary; Neuroscience Center, University of Pécs, 7602 Pécs, Hungary; Learning in Biological and Artificial Systems Research Group, Medical School, Institute of Physiology, University of Pécs, 7602 Pécs, Hungary
| | - Anita Kovács
- Medical School, Institute of Physiology, University of Pécs, Szigeti Str. 12, P.O. Box 99, 7602 Pécs, Hungary; Neuropeptides, Cognition, Animal Models of Neuropsychiatric Disorders Research Group, Medical School, Institute of Physiology, University of Pécs, 7602 Pécs, Hungary; Neuroscience Center, University of Pécs, 7602 Pécs, Hungary
| | - Zoltán Karádi
- Medical School, Institute of Physiology, University of Pécs, Szigeti Str. 12, P.O. Box 99, 7602 Pécs, Hungary; Neuroscience Center, University of Pécs, 7602 Pécs, Hungary; Cellular Bioimpedance Research Group, Szentágothai Research Center, University of Pécs, 7602 Pécs, Hungary; Molecular Endocrinology and Neurophysiology Research Group, Szentágothai Center, University of Pécs, 7602 Pécs, Hungary
| | - László Lénárd
- Medical School, Institute of Physiology, University of Pécs, Szigeti Str. 12, P.O. Box 99, 7602 Pécs, Hungary; Neuropeptides, Cognition, Animal Models of Neuropsychiatric Disorders Research Group, Medical School, Institute of Physiology, University of Pécs, 7602 Pécs, Hungary; Neuroscience Center, University of Pécs, 7602 Pécs, Hungary; Molecular Endocrinology and Neurophysiology Research Group, Szentágothai Center, University of Pécs, 7602 Pécs, Hungary
| | - Kristóf László
- Medical School, Institute of Physiology, University of Pécs, Szigeti Str. 12, P.O. Box 99, 7602 Pécs, Hungary; Neuropeptides, Cognition, Animal Models of Neuropsychiatric Disorders Research Group, Medical School, Institute of Physiology, University of Pécs, 7602 Pécs, Hungary; Neuroscience Center, University of Pécs, 7602 Pécs, Hungary.
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4
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Fam J, Holmes N, Westbrook RF. Stimulating oxytocin receptors in the basolateral amygdala enhances stimulus processing: Differential and consistent effects for stimuli paired with fear versus sucrose in extinction and reversal learning. Psychoneuroendocrinology 2024; 160:106917. [PMID: 38071877 DOI: 10.1016/j.psyneuen.2023.106917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/24/2023] [Accepted: 11/28/2023] [Indexed: 01/02/2024]
Abstract
Oxytocin (OT) influences a range of social behaviors by enhancing the salience of social cues and regulating the expression of specific social behaviors (e.g., maternal care versus defensive aggression). We previously showed that stimulating OT receptors in the basolateral amygdala of rats also enhanced the salience of fear conditioned stimuli: relative to rats given vehicle infusions, rats infused with [Thr4,Gly7]-oxytocin (TGOT), a selective OT receptor agonist, showed greater discrimination between a cue predictive of danger, and one that signaled safety. In the present series of experiments using male rats, the effects of OT receptor activation in the basolateral amygdala on stimulus processing were examined further using conditioning protocols that consist of changes in stimulus-outcome contingencies (i.e., extinction and reversal), and with stimuli paired with aversive (i.e., foot shock) and appetitive (i.e., sucrose) outcomes. It was revealed that the effects of OTR stimulation diverge for aversive and appetitive learning - enhancing the former but not the latter. However, across both types of learning, OTR stimulation enhanced the detection of conditioned stimuli. Overall, these results are consistent with an emerging view of OT's effects on stimulus salience; facilitating the detection of meaningful stimuli while reducing responding to those that are irrelevant.
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Affiliation(s)
- Justine Fam
- School of Psychology, University of New South Wales, Australia.
| | - Nathan Holmes
- School of Psychology, University of New South Wales, Australia
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5
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Schimmer J, Patwell R, Küppers S, Grinevich V. The Relationship Between Oxytocin and Alcohol Dependence. Curr Top Behav Neurosci 2023. [PMID: 37697074 DOI: 10.1007/7854_2023_444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/13/2023]
Abstract
The hypothalamic neuropeptide oxytocin (OT) is well known for its prosocial, anxiolytic, and ameliorating effects on various psychiatric conditions, including alcohol use disorder (AUD). In this chapter, we will first introduce the basic neurophysiology of the OT system and its interaction with other neuromodulatory and neurotransmitter systems in the brain. Next, we provide an overview over the current state of research examining the effects of acute and chronic alcohol exposure on the OT system as well as the effects of OT system manipulation on alcohol-related behaviors in rodents and humans. In rodent models of AUD, OT has been repeatedly shown to reduce ethanol consumption, particularly in models of acute alcohol exposure. In humans however, the results of OT administration on alcohol-related behaviors are promising but not yet conclusive. Therefore, we further discuss several physiological and methodological limitations to the effective application of OT in the clinic and how they may be mitigated by the application of synthetic OT receptor (OTR) agonists. Finally, we discuss the potential efficacy of cutting-edge pharmacology and gene therapies designed to specifically enhance endogenous OT release and thereby rescue deficient expression of OT in the brains of patients with severe forms of AUD and other incurable mental disorders.
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Affiliation(s)
- Jonas Schimmer
- Department of Neuropeptide Research in Psychiatry, Medical Faculty Mannheim, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany
| | - Ryan Patwell
- Department of Neuropeptide Research in Psychiatry, Medical Faculty Mannheim, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany
| | - Stephanie Küppers
- Department of Neuropeptide Research in Psychiatry, Medical Faculty Mannheim, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany
| | - Valery Grinevich
- Department of Neuropeptide Research in Psychiatry, Medical Faculty Mannheim, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany.
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6
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Li Y, Zhi W, Qi B, Wang L, Hu X. Update on neurobiological mechanisms of fear: illuminating the direction of mechanism exploration and treatment development of trauma and fear-related disorders. Front Behav Neurosci 2023; 17:1216524. [PMID: 37600761 PMCID: PMC10433239 DOI: 10.3389/fnbeh.2023.1216524] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/18/2023] [Indexed: 08/22/2023] Open
Abstract
Fear refers to an adaptive response in the face of danger, and the formed fear memory acts as a warning when the individual faces a dangerous situation again, which is of great significance to the survival of humans and animals. Excessive fear response caused by abnormal fear memory can lead to neuropsychiatric disorders. Fear memory has been studied for a long time, which is of a certain guiding effect on the treatment of fear-related disorders. With continuous technological innovations, the study of fear has gradually shifted from the level of brain regions to deeper neural (micro) circuits between brain regions and even within single brain regions, as well as molecular mechanisms. This article briefly outlines the basic knowledge of fear memory and reviews the neurobiological mechanisms of fear extinction and relapse, which aims to provide new insights for future basic research on fear emotions and new ideas for treating trauma and fear-related disorders.
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Affiliation(s)
- Ying Li
- College of Education, Hebei University, Baoding, China
- Laboratory of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Weijia Zhi
- Laboratory of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Bing Qi
- College of Education, Hebei University, Baoding, China
| | - Lifeng Wang
- Laboratory of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Xiangjun Hu
- College of Education, Hebei University, Baoding, China
- Laboratory of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China
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7
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Neurobiology of Maternal Behavior in Nonhuman Mammals: Acceptance, Recognition, Motivation, and Rejection. Animals (Basel) 2022; 12:ani12243589. [PMID: 36552508 PMCID: PMC9774276 DOI: 10.3390/ani12243589] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/11/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022] Open
Abstract
Among the different species of mammals, the expression of maternal behavior varies considerably, although the end points of nurturance and protection are the same. Females may display passive or active responses of acceptance, recognition, rejection/fear, or motivation to care for the offspring. Each type of response may indicate different levels of neural activation. Different natural stimuli can trigger the expression of maternal and paternal behavior in both pregnant or virgin females and males, such as hormone priming during pregnancy, vagino-cervical stimulation during parturition, mating, exposure to pups, previous experience, or environmental enrichment. Herein, we discuss how the olfactory pathways and the interconnections of the medial preoptic area (mPOA) with structures such as nucleus accumbens, ventral tegmental area, amygdala, and bed nucleus of stria terminalis mediate maternal behavior. We also discuss how the triggering stimuli activate oxytocin, vasopressin, dopamine, galanin, and opioids in neurocircuitries that mediate acceptance, recognition, maternal motivation, and rejection/fear.
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8
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Rashidi M, Maier E, Dekel S, Sütterlin M, Wolf RC, Ditzen B, Grinevich V, Herpertz SC. Peripartum effects of synthetic oxytocin: The good, the bad, and the unknown. Neurosci Biobehav Rev 2022; 141:104859. [PMID: 36087759 DOI: 10.1016/j.neubiorev.2022.104859] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 08/23/2022] [Accepted: 09/03/2022] [Indexed: 11/30/2022]
Abstract
The first clinical applications of oxytocin (OT) were in obstetrics as a hormone to start and speed up labor and to control postpartum hemorrhage. Discoveries in the 1960s and 1970s revealed that the effects of OT are not limited to its peripheral actions around birth and milk ejection. Indeed, OT also acts as a neuromodulator in the brain affecting fear memory, social attachment, and other forms of social behaviors. The peripheral and central effects of OT have been separately subject to extensive scrutiny. However, the effects of peripheral OT-particularly in the form of administration of synthetic OT (synOT) around birth-on the central nervous system are surprisingly understudied. Here, we provide a narrative review of the current evidence, suggest putative mechanisms of synOT action, and provide new directions and hypotheses for future studies to bridge the gaps between neuroscience, obstetrics, and psychiatry.
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Affiliation(s)
- Mahmoud Rashidi
- Department of General Psychiatry, Heidelberg University, Heidelberg, Germany.
| | - Eduard Maier
- Department of Neuropeptide Research in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Sharon Dekel
- Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA; Department of Psychiatry, Harvard Medical School, Boston, MA, USA
| | - Marc Sütterlin
- Department of Gynecology and Obstetrics, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Robert C Wolf
- Department of General Psychiatry, Heidelberg University, Heidelberg, Germany
| | - Beate Ditzen
- Institute of Medical Psychology, Center for Psychosocial Medicine, Heidelberg University, Heidelberg, Germany
| | - Valery Grinevich
- Department of Neuropeptide Research in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Sabine C Herpertz
- Department of General Psychiatry, Heidelberg University, Heidelberg, Germany
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9
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Ryabinin AE, Zhang Y. Barriers and Breakthroughs in Targeting the Oxytocin System to Treat Alcohol Use Disorder. Front Psychiatry 2022; 13:842609. [PMID: 35295777 PMCID: PMC8919088 DOI: 10.3389/fpsyt.2022.842609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 02/04/2022] [Indexed: 11/13/2022] Open
Abstract
Development of better treatments for alcohol use disorder (AUD) is urgently needed. One promising opportunity for this development is the potential of targeting the oxytocin peptide system. Preclinical studies showed that administration of exogenous oxytocin or, more recently, stimulation of neurons expressing endogenous oxytocin lead to a decreased alcohol consumption across several rodent models. Initial clinical studies also showed that administration of oxytocin decreased craving for alcohol and heavy alcohol drinking. However, several more recent clinical studies were not able to replicate these effects. Thus, although targeting the oxytocin system holds promise for the treatment of AUD, more nuanced approaches toward development and application of these treatments are needed. In this mini-review we discuss potential caveats resulting in differential success of attempts to use oxytocin for modulating alcohol use disorder-related behaviors in clinical studies and evaluate three directions in which targeting the oxytocin system could be improved: (1) increasing potency of exogenously administered oxytocin, (2) developing oxytocin receptor agonists, and (3) stimulating components of the endogenous oxytocin system. Both advances and potential pitfalls of these directions are discussed.
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Affiliation(s)
- Andrey E. Ryabinin
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, United States
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10
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Glavonic E, Mitic M, Adzic M. Hallucinogenic drugs and their potential for treating fear-related disorders: Through the lens of fear extinction. J Neurosci Res 2022; 100:947-969. [PMID: 35165930 DOI: 10.1002/jnr.25017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 12/17/2021] [Accepted: 01/05/2022] [Indexed: 12/29/2022]
Abstract
Fear-related disorders, mainly phobias and post-traumatic stress disorder, are highly prevalent, debilitating disorders that pose a significant public health problem. They are characterized by aberrant processing of aversive experiences and dysregulated fear extinction, leading to excessive expression of fear and diminished quality of life. The gold standard for treating fear-related disorders is extinction-based exposure therapy (ET), shown to be ineffective for up to 35% of subjects. Moreover, ET combined with traditional pharmacological treatments for fear-related disorders, such as selective serotonin reuptake inhibitors, offers no further advantage to patients. This prompted the search for ways to improve ET outcomes, with current research focused on pharmacological agents that can augment ET by strengthening fear extinction learning. Hallucinogenic drugs promote reprocessing of fear-imbued memories and induce positive mood and openness, relieving anxiety and enabling the necessary emotional engagement during psychotherapeutic interventions. Mechanistically, hallucinogens induce dynamic structural and functional neuroplastic changes across the fear extinction circuitry and temper amygdala's hyperreactivity to threat-related stimuli, effectively mitigating one of the hallmarks of fear-related disorders. This paper provides the first comprehensive review of hallucinogens' potential to alleviate symptoms of fear-related disorders by focusing on their effects on fear extinction and the underlying molecular mechanisms. We overview both preclinical and clinical studies and emphasize the advantages of hallucinogenic drugs over current first-line treatments. We highlight 3,4-methylenedioxymethamphetamine and ketamine as the most effective therapeutics for fear-related disorders and discuss the potential molecular mechanisms responsible for their potency with implications for improving hallucinogen-assisted psychotherapy.
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Affiliation(s)
- Emilija Glavonic
- Department of Molecular Biology and Endocrinology, "VINČA" Institute of Nuclear Sciences-National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Milos Mitic
- Department of Molecular Biology and Endocrinology, "VINČA" Institute of Nuclear Sciences-National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Miroslav Adzic
- Department of Molecular Biology and Endocrinology, "VINČA" Institute of Nuclear Sciences-National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
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11
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Bazaz A, Ghanbari A, Vafaei AA, Khaleghian A, Rashidy-Pour A. Oxytocin in dorsal hippocampus facilitates auditory fear memory extinction in rats. Neuropharmacology 2022; 202:108844. [PMID: 34687711 DOI: 10.1016/j.neuropharm.2021.108844] [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: 06/08/2021] [Revised: 09/11/2021] [Accepted: 10/14/2021] [Indexed: 10/20/2022]
Abstract
Fear extinction is impaired in some psychiatric disorders. Any treatment that facilitates the extinction of fear is a way to advance the treatment of related psychiatric disorders. Recent studies have highlighted the role of oxytocin (OT) in fear extinction, but the endogenous release of OT during fear extinction in the dorsal hippocampal (dHPC) is not clear. We investigated the release of OT during fear extinction and the role of the HPC - medial prefrontal cortex (mPFC) circuit and BDNF in the effects of exogenous OT on auditory fear conditioning in male rats. We found that the release of endogenous OT in the dHPC is significantly increased during the fear extinction process as measured by the microdialysis method. Increased freezing response in the OT-treated rats compared to saline-treated rats showed that exogenous OT in the dHPC enhanced the fear extinction. Injection of BDNF antagonist (ANA-12) into the infralimbic (IL) blocked the effect of exogenous OT on the dHPC. Following OT injection, BDNF levels increased in the dHPC, ventral HPC, and IL cortex; but decreased in the prelimbic cortex (PL). Finally, OT microinjected into the dHPC significantly increased neural activity of pyramidal neurons of the CA1-vHPC and IL but decreased the neural activity in the PL cortex. Our findings strongly support that the dHPC endogenous OT plays a crucial role in enhancing fear extinction. It seems that the activation of the HPC-mPFC pathway, and consequently, the release of BDNF in the IL cortex mediates the enhancing effects of OT on fear extinction.
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Affiliation(s)
- Amir Bazaz
- Student Research Committee, Semnan University of Medical Sciences, Semnan, Iran
| | - Ali Ghanbari
- Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran
| | - Abbas Ali Vafaei
- Department of physiology, Semnan University of Medical Sciences, Semnan, Iran
| | - Ali Khaleghian
- Department of Biochemistry, Semnan University of Medical Sciences, Semnan, Iran
| | - Ali Rashidy-Pour
- Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran.
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12
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Takayanagi Y, Onaka T. Roles of Oxytocin in Stress Responses, Allostasis and Resilience. Int J Mol Sci 2021; 23:ijms23010150. [PMID: 35008574 PMCID: PMC8745417 DOI: 10.3390/ijms23010150] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 12/17/2021] [Accepted: 12/19/2021] [Indexed: 02/06/2023] Open
Abstract
Oxytocin has been revealed to work for anxiety suppression and anti-stress as well as for psychosocial behavior and reproductive functions. Oxytocin neurons are activated by various stressful stimuli. The oxytocin receptor is widely distributed within the brain, and oxytocin that is released or diffused affects behavioral and neuroendocrine stress responses. On the other hand, there has been an increasing number of reports on the role of oxytocin in allostasis and resilience. It has been shown that oxytocin maintains homeostasis, shifts the set point for adaptation to a changing environment (allostasis) and contributes to recovery from the shifted set point by inducing active coping responses to stressful stimuli (resilience). Recent studies have suggested that oxytocin is also involved in stress-related disorders, and it has been shown in clinical trials that oxytocin provides therapeutic benefits for patients diagnosed with stress-related disorders. This review includes the latest information on the role of oxytocin in stress responses and adaptation.
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Hale LH, Tickerhoof MC, Smith AS. Chronic intranasal oxytocin reverses stress-induced social avoidance in female prairie voles. Neuropharmacology 2021; 198:108770. [PMID: 34461067 DOI: 10.1016/j.neuropharm.2021.108770] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 12/14/2022]
Abstract
Social anxiety disorder (SAD) is a prevalent mental illness in both men and women, but current treatment approaches with selective serotonin reuptake inhibitors (SSRI) have limited success. The neuropeptide oxytocin (OXT) has become a therapeutic target due to its prosocial and anxiolytic effects. Nevertheless, no research has focused on the impact of chronic OXT treatment in animal models of SAD. Social defeat stress is an animal model of social conflict that reliably induces a social avoidance phenotype, reflecting symptoms observed in individuals suffering from SAD. Here, we used the socially monogamous prairie vole, which exhibits aggressive behavior in both sexes, to examine the effects of OXT and SSRI treatment following social defeat stress in males and females. Defeated voles became avoidant in unfamiliar social situations as early as one day after defeat experience, and this phenotype persisted for at least eight weeks. OXT receptor (OXTR) binding in mesocorticolimbic and paralimbic regions was reduced in defeated females during the eight-week recovery period. In males, serotonin 1A receptor binding was decreased in the basolateral amygdala and dorsal raphe nucleus starting at one week and four weeks post-defeat, respectively. Chronic intranasal treatment with OXT had a negative effect on sociability and mesolimbic OXTR binding in non-defeated females. However, chronic intranasal OXT promoted social engagement and increased mesolimbic OXTR binding in defeated females but not males. SSRI treatment led to only modest effects. This study identifies a sex-specific and stress-dependent function of intranasal OXT on mesolimbic OXTR and social behaviors.
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Affiliation(s)
- Luanne H Hale
- Department of Pharmacology and Toxicology, Pharmacy School, University of Kansas, Lawrence, KS, USA
| | - Maria C Tickerhoof
- Department of Pharmacology and Toxicology, Pharmacy School, University of Kansas, Lawrence, KS, USA
| | - Adam S Smith
- Department of Pharmacology and Toxicology, Pharmacy School, University of Kansas, Lawrence, KS, USA.
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Baldi E, Costa A, Rani B, Passani MB, Blandina P, Romano A, Provensi G. Oxytocin and Fear Memory Extinction: Possible Implications for the Therapy of Fear Disorders? Int J Mol Sci 2021; 22:10000. [PMID: 34576161 PMCID: PMC8467761 DOI: 10.3390/ijms221810000] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/07/2021] [Accepted: 09/10/2021] [Indexed: 02/07/2023] Open
Abstract
Several psychiatric conditions such as phobias, generalized anxiety, and post-traumatic stress disorder (PTSD) are characterized by pathological fear and anxiety. The main therapeutic approach used in the management of these disorders is exposure-based therapy, which is conceptually based upon fear extinction with the formation of a new safe memory association, allowing the reduction in behavioral conditioned fear responses. Nevertheless, this approach is only partially resolutive, since many patients have difficulty following the demanding and long process, and relapses are frequently observed over time. One strategy to improve the efficacy of the cognitive therapy is the combination with pharmacological agents. Therefore, the identification of compounds able to strengthen the formation and persistence of the inhibitory associations is a key goal. Recently, growing interest has been aroused by the neuropeptide oxytocin (OXT), which has been shown to have anxiolytic effects. Furthermore, OXT receptors and binding sites have been found in the critical brain structures involved in fear extinction. In this review, the recent literature addressing the complex effects of OXT on fear extinction at preclinical and clinical levels is discussed. These studies suggest that the OXT roles in fear behavior are due to its local effects in several brain regions, most notably, distinct amygdaloid regions.
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Affiliation(s)
- Elisabetta Baldi
- Section of Physiological Sciences, Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy;
| | - Alessia Costa
- Section of Clinical Pharmacology and Oncology, Department of Health Sciences (DSS), University of Florence, 50139 Florence, Italy; (A.C.); (B.R.); (M.B.P.)
| | - Barbara Rani
- Section of Clinical Pharmacology and Oncology, Department of Health Sciences (DSS), University of Florence, 50139 Florence, Italy; (A.C.); (B.R.); (M.B.P.)
| | - Maria Beatrice Passani
- Section of Clinical Pharmacology and Oncology, Department of Health Sciences (DSS), University of Florence, 50139 Florence, Italy; (A.C.); (B.R.); (M.B.P.)
| | - Patrizio Blandina
- Section of Pharmacology of Toxicology, Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, 50139 Florence, Italy;
| | - Adele Romano
- Department of Physiology and Pharmacology ‘V. Erspamer’, Sapienza University of Rome, 00185 Rome, Italy;
| | - Gustavo Provensi
- Section of Pharmacology of Toxicology, Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, 50139 Florence, Italy;
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Harshaw C, Lanzkowsky J, Tran AQD, Bradley AR, Jaime M. Oxytocin and 'social hyperthermia': Interaction with β 3-adrenergic receptor-mediated thermogenesis and significance for the expression of social behavior in male and female mice. Horm Behav 2021; 131:104981. [PMID: 33878523 DOI: 10.1016/j.yhbeh.2021.104981] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 04/02/2021] [Accepted: 04/03/2021] [Indexed: 02/07/2023]
Abstract
Oxytocin (OT) is a critical regulator of multiple facets of energy homeostasis, including brown adipose tissue (BAT) thermogenesis. Nevertheless, it is unclear what, if any, consequence the thermoregulatory and metabolic effects of OT have for the display of social behavior in adult rodents. Here, we examine the contribution of the OT receptor (OTR) and β3 adrenergic receptor (β3AR) to the increase in body temperature that typically accompanies social interaction (i.e., social hyperthermia; SH) and whether SH relates to the expression of social behavior in adult mice. Specifically, we examined how OTR antagonism via peripheral injection of L-368,899 (10 mg/kg) affects the expression of social behavior in C57BL/6J mice, in the presence of active/agonized versus antagonized β3AR, the receptor known to mediate stress-induced BAT thermogenesis. After drug treatment and a 30 min delay, mice were provided a 10 min social interaction test with an unfamiliar, same-sex conspecific. We hypothesized that OTR and β3AR/BAT interact to influence behavior during social interaction, with at least some effects of OT on social behavior dependent upon OT's thermal effects via β3AR/BAT. We found that OTR-mediated temperature elevation is largely responsible for SH during social interaction in mice-albeit not substantially via β3AR-dependent BAT thermogenesis. Further, our results reveal a complex relationship between OTR, β3AR, social hyperthermia and the display of specific social behaviors, with SH most closely associated with anxiety and/or vigilance-related behaviors-that is, behaviors that antagonize or interfere with the initiation of close, non-agonistic social behavior.
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Affiliation(s)
- Christopher Harshaw
- Department of Psychology, University of New Orleans, New Orleans, LA, United States of America.
| | - Jessica Lanzkowsky
- Department of Psychology, University of New Orleans, New Orleans, LA, United States of America
| | | | - Alana Rose Bradley
- Department of Psychology, University of New Orleans, New Orleans, LA, United States of America
| | - Mark Jaime
- Division of Science, Indiana University-Purdue University, Columbus, Columbus, IN, United States of America
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Baettig L, Baeumelt A, Ernst J, Boeker H, Grimm S, Richter A. The awareness of the scared - context dependent influence of oxytocin on brain function. Brain Imaging Behav 2021; 14:2073-2083. [PMID: 31317388 DOI: 10.1007/s11682-019-00143-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Oxytocin is both a hormone and a neurotransmitter and has been originally recognized for its role in childbirth and lactation. Later, it became widely known as a "cuddle hormone" that induces trusting behavior towards strangers and reduces social stress and anxiety. Several studies showed that oxytocin influences empathic behavior and has prosocial effects. The anterior cingulate cortex and the anterior insula are brain regions that are active when humans observe fear in others. Therefore, the aim of this study was to investigate whether oxytocin administration affects activity in these regions depending on whether a threat is directed at another person (empathy) compared to when the threat is directed at the subject itself (fear). Our findings demonstrate increased anterior cingulate cortex activation after oxytocin administration in the fear, but not in the empathy condition. Furthermore, oxytocin administration was associated with deceased anterior insula activity in the empathy condition. However, our findings do not support the idea that oxytocin generally augments activity in brain regions associated with empathy. Thereby this study supports current research questioning that oxytocin has exclusively prosocial effects on human behavior. Rather, the effect of oxytocin depends on various contextual (e.g. presence of a familiar person) and interindividual (e.g. sex, mental disorder) factors. Therefore, to consider oxytocin an empathy inducing hormone is an oversimplification and future research should focus on factors moderating oxytocin effects.
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Affiliation(s)
- Linda Baettig
- Department of Consultation-Liaison-Psychiatry and Psychosomatic Medicine, University Hospital Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland
| | - Andreas Baeumelt
- Department of Psychiatry, Psychotherapy, and Psychosomatics, University Hospital of Psychiatry Zurich, Zurich, Switzerland
| | - Jutta Ernst
- Department of Psychiatry, Psychotherapy, and Psychosomatics, University Hospital of Psychiatry Zurich, Zurich, Switzerland
| | - Heinz Boeker
- Department of Psychiatry, Psychotherapy, and Psychosomatics, University Hospital of Psychiatry Zurich, Zurich, Switzerland
| | - Simone Grimm
- Department of Psychiatry, Psychotherapy, and Psychosomatics, University Hospital of Psychiatry Zurich, Zurich, Switzerland
- Department of Psychiatry, Charité, Campus Benjamin Franklin, Berlin, Germany
- Medical School Berlin, Berlin, Germany
| | - Andre Richter
- Department of Consultation-Liaison-Psychiatry and Psychosomatic Medicine, University Hospital Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland.
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Intranasal oxytocin decreases fear generalization in males, but does not modulate discrimination threshold. Psychopharmacology (Berl) 2021; 238:677-689. [PMID: 33241482 DOI: 10.1007/s00213-020-05720-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 11/13/2020] [Indexed: 10/22/2022]
Abstract
BACKGROUND A previously acquired fear response often spreads to perceptually or conceptually close stimuli or contexts. This process, known as fear generalization, facilitates the avoidance of danger, and dysregulations in this process play an important role in anxiety disorders. Oxytocin (OT) has been shown to modulate fear learning, yet effects on fear generalization remain unknown. METHODS We employed a randomized, placebo-controlled, double-blind, between-subject design during which healthy male participants received either intranasal OT or placebo (PLC) following fear acquisition and before fear generalization with concomitant acquisition of skin conductance responses (SCRs). Twenty-four to 72 h before the fear learning and immediately after the fear generalization task, participants additionally complete a discrimination threshold task. RESULTS Relative to PLC, OT significantly reduced perceived risk and SCRs towards the CS+ and GS1 (the generalization stimulus that is most similar to CS+) during fear generalization, whereas the discrimination threshold was not affected. CONCLUSIONS Together, the results suggest that OT can attenuate fear generalization in the absence of effects on discrimination threshold. This study provides the first evidence for effects of OT on fear generalization in humans and suggests that OT may have therapeutic potential in anxiety disorders characterized by dysregulated fear generalization.
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Limbic Neuropeptidergic Modulators of Emotion and Their Therapeutic Potential for Anxiety and Post-Traumatic Stress Disorder. J Neurosci 2021; 41:901-910. [PMID: 33472824 DOI: 10.1523/jneurosci.1647-20.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 11/06/2020] [Accepted: 11/11/2020] [Indexed: 12/20/2022] Open
Abstract
Post-traumatic stress disorder (PTSD) is characterized by hypervigilance, increased reactivity to unpredictable versus predictable threat signals, deficits in fear extinction, and an inability to discriminate between threat and safety. First-line pharmacotherapies for psychiatric disorders have limited therapeutic efficacy in PTSD. However, recent studies have advanced our understanding of the roles of several limbic neuropeptides in the regulation of defensive behaviors and in the neural processes that are disrupted in PTSD. For example, preclinical studies have shown that blockers of tachykinin pathways, such as the Tac2 pathway, attenuate fear memory consolidation in mice and thus might have unique potential as early post-trauma interventions to prevent PTSD development. Targeting this pathway might also be beneficial in regulating other symptoms of PTSD, including trauma-induced aggressive behavior. In addition, preclinical and clinical studies have shown the important role of angiotensin receptors in fear extinction and the promise of using angiotensin II receptor blockade to reduce PTSD symptom severity. Additional preclinical studies have demonstrated that the oxytocin receptors foster accurate fear discrimination by facilitating fear responses to predictable versus unpredictable threats. Complementary human imaging studies demonstrate unique neural targets of intranasal oxytocin and compare its efficacy with well-established anxiolytic treatments. Finally, promising data from human subjects have demonstrated that a selective vasopressin 1A receptor antagonist reduces anxiety induced by unpredictable threats. This review highlights these novel promising targets for the treatment of unique core elements of PTSD pathophysiology.
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Inserra A, De Gregorio D, Gobbi G. Psychedelics in Psychiatry: Neuroplastic, Immunomodulatory, and Neurotransmitter Mechanisms. Pharmacol Rev 2020; 73:202-277. [PMID: 33328244 DOI: 10.1124/pharmrev.120.000056] [Citation(s) in RCA: 100] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Mounting evidence suggests safety and efficacy of psychedelic compounds as potential novel therapeutics in psychiatry. Ketamine has been approved by the Food and Drug Administration in a new class of antidepressants, and 3,4-methylenedioxymethamphetamine (MDMA) is undergoing phase III clinical trials for post-traumatic stress disorder. Psilocybin and lysergic acid diethylamide (LSD) are being investigated in several phase II and phase I clinical trials. Hence, the concept of psychedelics as therapeutics may be incorporated into modern society. Here, we discuss the main known neurobiological therapeutic mechanisms of psychedelics, which are thought to be mediated by the effects of these compounds on the serotonergic (via 5-HT2A and 5-HT1A receptors) and glutamatergic [via N-methyl-d-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors] systems. We focus on 1) neuroplasticity mediated by the modulation of mammalian target of rapamycin-, brain-derived neurotrophic factor-, and early growth response-related pathways; 2) immunomodulation via effects on the hypothalamic-pituitary-adrenal axis, nuclear factor ĸB, and cytokines such as tumor necrosis factor-α and interleukin 1, 6, and 10 production and release; and 3) modulation of serotonergic, dopaminergic, glutamatergic, GABAergic, and norepinephrinergic receptors, transporters, and turnover systems. We discuss arising concerns and ways to assess potential neurobiological changes, dependence, and immunosuppression. Although larger cohorts are required to corroborate preliminary findings, the results obtained so far are promising and represent a critical opportunity for improvement of pharmacotherapies in psychiatry, an area that has seen limited therapeutic advancement in the last 20 years. Studies are underway that are trying to decouple the psychedelic effects from the therapeutic effects of these compounds. SIGNIFICANCE STATEMENT: Psychedelic compounds are emerging as potential novel therapeutics in psychiatry. However, understanding of molecular mechanisms mediating improvement remains limited. This paper reviews the available evidence concerning the effects of psychedelic compounds on pathways that modulate neuroplasticity, immunity, and neurotransmitter systems. This work aims to be a reference for psychiatrists who may soon be faced with the possibility of prescribing psychedelic compounds as medications, helping them assess which compound(s) and regimen could be most useful for decreasing specific psychiatric symptoms.
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Affiliation(s)
- Antonio Inserra
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, Quebec, Canada
| | - Danilo De Gregorio
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, Quebec, Canada
| | - Gabriella Gobbi
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, Quebec, Canada
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20
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Lapp HE, Bartlett AA, Zup SL, Hunter RG, Moore CL. Early experience alters developmental trajectory of central oxytocin systems involved in hypothalamic-pituitary-adrenal axis regulation in Long-Evans rats. Horm Behav 2020; 126:104822. [PMID: 32730760 DOI: 10.1016/j.yhbeh.2020.104822] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 07/20/2020] [Accepted: 07/21/2020] [Indexed: 11/25/2022]
Abstract
Oxytocin is important for postnatal developmental experiences for mothers, infants, and transactions between them. Oxytocin is also implicated in adult affiliative behaviors, including social buffering of stress. There is evidence for connections between early life experience and adult oxytocin system functioning, but effects of early experience on behavioral, endocrine, and neurophysiological outcomes related to adult social buffering are not well explored. We use a limited bedding and nesting (LBN) material paradigm as an environmental disruption of early experiences and assessed central oxytocin systems in brain regions related to hypothalamic-pituitary-adrenal (HPA) axis regulation (paraventricular nucleus of the hypothalamus, amygdala, hippocampus). We also assessed developmentally-appropriate social behaviors and HPA reactivity during social buffering testing in adulthood. LBN litters had larger huddles and more pups visible compared to control litters during the first two weeks of life. LBN also altered the developmental trajectory of oxytocin-expressing cells and oxytocin receptor cells, with increases in oxytocin receptor cells at P15 in LBN pups. By adulthood, LBN females had more and LBN males had fewer oxytocin and oxytocin receptor cells in these areas compared to sex-matched controls. Adult LBN females, but not LBN males, had behavioral changes during social interaction and social buffering testing. The sex-specific effects of early experience on central oxytocin systems and social behavior may contribute to female resilience to early life adversity.
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Affiliation(s)
- Hannah E Lapp
- University of Massachusetts Boston, Department of Psychology, 100 Morrissey Rd., Boston, MA 02125, United States of America.
| | - Andrew A Bartlett
- University of Massachusetts Boston, Department of Psychology, 100 Morrissey Rd., Boston, MA 02125, United States of America
| | - Susan L Zup
- University of Massachusetts Boston, Department of Psychology, 100 Morrissey Rd., Boston, MA 02125, United States of America
| | - Richard G Hunter
- University of Massachusetts Boston, Department of Psychology, 100 Morrissey Rd., Boston, MA 02125, United States of America
| | - Celia L Moore
- University of Massachusetts Boston, Department of Psychology, 100 Morrissey Rd., Boston, MA 02125, United States of America
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21
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Sex-dimorphic role of prefrontal oxytocin receptors in social-induced facilitation of extinction in juvenile rats. Transl Psychiatry 2020; 10:356. [PMID: 33077706 PMCID: PMC7572379 DOI: 10.1038/s41398-020-01040-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 09/15/2020] [Accepted: 10/02/2020] [Indexed: 11/26/2022] Open
Abstract
We previously reported that in the adult animal extinction in pairs resulted in enhanced extinction, showing that social presence can reduce previously acquired fear responses. Based on our findings that juvenile and adult animals differ in the mechanisms of extinction, here we address whether the social presence of a conspecific affects extinction in juvenile animals similarly to adults. We further address whether such presence has a different impact on juvenile males and females. To that end, we examined in our established experimental setting whether conditioned male and female animals extinguish contextual fear memory better while in pairs. Taking advantage of the role of oxytocin (OT) in the mediation of extinction memory and social interaction, we also study the effect of antagonizing the OT receptors (OTR) either systemically or in the prefrontal cortex on social interaction-induced effects of fear extinction. The results show that social presence accelerates extinction in males and females as compared to the single condition. Yet, we show differential and opposing effects of an OTR antagonist in both sexes. Whereas in females, the systemic application of an OTR antagonist is associated with impaired extinction, it is associated with enhanced extinction in males. In contrast, prefrontal OT is not engaged in extinction in juvenile males, while is it is critical in females. Previously reported differences in the levels of prefrontal OT between males and females might explain the differences in OT action. These results suggest that even during the juvenile period, critical mechanisms are differently involved in the regulation of fear in males and females.
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Olivera-Pasilio V, Dabrowska J. Oxytocin Promotes Accurate Fear Discrimination and Adaptive Defensive Behaviors. Front Neurosci 2020; 14:583878. [PMID: 33071751 PMCID: PMC7538630 DOI: 10.3389/fnins.2020.583878] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 08/24/2020] [Indexed: 12/21/2022] Open
Abstract
The nonapeptide, oxytocin (OT), known for its role in social bonding and attachment formation, has demonstrated anxiolytic properties in animal models and human studies. However, its role in the regulation of fear responses appears more complex, brain site-specific, sex-specific, and dependent on a prior stress history. Studies have shown that OT neurons in the hypothalamus are activated during cued and contextual fear conditioning and during fear recall, highlighting the recruitment of endogenous oxytocin system in fear learning. OT is released into the extended amygdala, which contains the central nucleus of the amygdala (CeA) and the bed nucleus of the stria terminalis (BNST), both critical for the regulation of fear and anxiety-like behaviors. Behavioral studies report that OT in the CeA reduces contextual fear responses; whereas in the BNST, OT receptor (OTR) neurotransmission facilitates cued fear and reduces fear responses to un-signaled, diffuse threats. These ostensibly contrasting behavioral effects support growing evidence that OT works to promote fear discrimination by reducing contextual fear or fear of diffuse threats, yet strengthening fear responses to imminent and predictable threats. Recent studies from the basolateral nucleus of the amygdala (BLA) support this notion and show that activation of OTR in the BLA facilitates fear discrimination by increasing fear responses to discrete cues. Also, OTR transmission in the CeA has been shown to mediate a switch from passive freezing to active escape behaviors in confrontation with an imminent, yet escapable threat but reduce reactivity to distant threats. Therefore, OT appears to increase the salience of relevant threat-signaling cues yet reduce fear responses to un-signaled, distant, or diffuse threats. Lastly, OTR signaling has been shown to underlie emotional discrimination between conspecifics during time of distress, social transmission of fear, and social buffering of fear. As OT has been shown to enhance salience of both positive and negative social experiences, it can also serve as a warning system against potential threats in social networks. Here, we extend the social salience hypothesis by proposing that OT enhances the salience of relevant environmental cues also in non-social contexts, and as such promotes active defensive behaviors.
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Affiliation(s)
- Valentina Olivera-Pasilio
- Center for the Neurobiology of Stress Resilience and Psychiatric Disorders, Rosalind Franklin University of Medicine and Science, North Chicago, IL, United States.,Discipline of Cellular and Molecular Pharmacology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, United States.,School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science, North Chicago, IL, United States
| | - Joanna Dabrowska
- Center for the Neurobiology of Stress Resilience and Psychiatric Disorders, Rosalind Franklin University of Medicine and Science, North Chicago, IL, United States.,Discipline of Cellular and Molecular Pharmacology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, United States.,School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science, North Chicago, IL, United States
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23
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Yaseen A, Shrivastava K, Zuri Z, Hatoum OA, Maroun M. Prefrontal Oxytocin is Involved in Impairments in Prefrontal Plasticity and Social Memory Following Acute Exposure to High Fat Diet in Juvenile Animals. Cereb Cortex 2020; 29:1900-1909. [PMID: 29608644 DOI: 10.1093/cercor/bhy070] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 03/02/2018] [Accepted: 03/07/2018] [Indexed: 02/07/2023] Open
Abstract
Juvenility represents a critical developmental phase during which exposure to a high fat diet (HFD) can severely modify cognitive and emotional functioning. The purpose of this study was to address how short and acute exposure to a HFD during juvenility affects social memory recognition and prefrontal long-term potentiation (LTP). As LTP and social memory depend on the neuromodulator oxytocin (OXY) and due to its role in metabolism, we also examined the effects of OXY in mediating HFD-induced alterations in social memory and LTP. Our results show that short exposure to a HFD during juvenility impairs social preference memory and prefrontal LTP. Interestingly, whereas systemic injections of OXY reversed the impairments in HFD-fed animals and impaired LTP and memory in control animals; prefrontal injections of the OXY agonist TGOT reversed the effects in HFD animals without affecting control animals. Exposure to HFD was associated with a reduction in the levels of OXY in the prefrontal compared to control animals. Interestingly, the restoration of social memory by TGOT in HFD animals was also associated with normalization of OXY in the prefrontal. These results point to a role that prefrontal OXY has in mediating the effects of HFD on memory and plasticity.
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Affiliation(s)
- Aseel Yaseen
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Kuldeep Shrivastava
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Zohar Zuri
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Ossama A Hatoum
- Department of Surgery B-HaEmek Medical Center in Afula and Faculty of Medicine, Technion: Israel Institute of Technology, Haifa, Israel
| | - Mouna Maroun
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
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Selective sub-nucleus effects of intra-amygdala oxytocin on fear extinction. Behav Brain Res 2020; 393:112798. [PMID: 32653556 DOI: 10.1016/j.bbr.2020.112798] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 06/16/2020] [Accepted: 07/03/2020] [Indexed: 01/20/2023]
Abstract
There is growing evidence that the neuropeptide oxytocin (OT) modulates fear and extinction in humans and rodents through actions in corticolimbic circuits including the central amygdala (CeA). Prior studies have, however, been limited to subjects that exhibit intact basal extinction, rather than extinction-impaired populations that could potentially therapeutically benefit from viable OT-targeting treatments. Here, we assessed the effects of pre-extinction training infusion of OT into the CeA, or basolateral amygdala (BLA), on extinction in an inbred mouse strain (S1) model of impaired extinction. We found that intra-CeA OT, at a dose of 0.01 μg, enabled extinction memory formation, as evidenced by lesser freezing as compared to vehicle-infused controls on a drug-free retrieval test. Conversely, infusion of a higher, 1.0 μg OT dose, markedly reduced freezing and increased grooming during extinction training and produced elevated freezing on drug-free retrieval. Infusion of the 0.01 μg dose into the BLA was without behavioral effects. Together, our data show that OT acts in a dose-dependent manner within the CeA to promote extinction in otherwise extinction-deficient mice. These findings provide further support for the potential utility of OT as an adjunctive treatment to extinction-based therapies for trauma and anxiety disorders.
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van den Burg EH, Hegoburu C. Modulation of expression of fear by oxytocin signaling in the central amygdala: From reduction of fear to regulation of defensive behavior style. Neuropharmacology 2020; 173:108130. [PMID: 32389750 DOI: 10.1016/j.neuropharm.2020.108130] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 04/28/2020] [Accepted: 05/03/2020] [Indexed: 12/17/2022]
Abstract
Many studies in preclinical animal models have described fear-reducing effects of the neuropeptide oxytocin in the central nucleus of the amygdala. However, recent studies have refined the role of oxytocin in the central amygdala, which may extend to the selection of an active defensive coping style in the face of immediate threat, and also fear-enhancing effects have been reported. On top of this, oxytocin enables the discrimination of unfamiliar conspecifics on the basis of their emotional state, which could allow for the selection of an appropriate coping style. This is in line with many observations that support the hypothesis that the precise outcome of oxytocin signaling in the central amygdala or other brain regions depends on the emotional or physiological state of an animal. In this review, we highlight a number of studies to exemplify the diverse effects oxytocin exerts on fear in the central amygdala of rodents. These are discussed in the context of the organization of the neural network within the central amygdala and in relation to the oxytocin-synthesizing neurons in the hypothalamus.
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Affiliation(s)
- Erwin H van den Burg
- Center for Psychiatric Neurosciences, Lausanne University Hospital Center (CHUV), Prilly, Lausanne, Switzerland.
| | - Chloé Hegoburu
- Center for Psychiatric Neurosciences, Lausanne University Hospital Center (CHUV), Prilly, Lausanne, Switzerland.
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De Oliveira Sergio T, Frias AT, Vilela-Costa HH, De Oliveira DC, Zuardi AW, Zangrossi H. Serotonin mediates the panicolytic-like effect of oxytocin in the dorsal periaqueductal gray. J Psychopharmacol 2020; 34:383-390. [PMID: 32108540 DOI: 10.1177/0269881120907960] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
INTRODUCTION AND OBJECTIVES Oxytocin (OT) has been widely linked to positive social interactions, and there is great interest in OT as a therapy for a variety of neuropsychiatric conditions. Recent evidence also suggests that OT can play an important role in the mediation of anxiety-associated defensive responses, including a role for serotonin (5-HT) neurotransmission in this action. However, it is presently unknown whether OT additionally regulates the expression of panic-related behaviors, such as escape, by acting in the dorsal periaqueductal gray (dPAG), a key panic-regulating area. This study aimed to investigate the consequence of OT injection in the dPAG on escape expression and whether facilitation of 5-HT neurotransmission in this midbrain area is implicated in this action. METHODS Male Wistar rats were injected with OT in the dPAG and tested for escape expression in the elevated T-maze (ETM) and dPAG electrical stimulation tests. Using the latter test, OT's effect was also investigated after previous intra-dPAG injection of the OT receptor antagonist atosiban, the preferential antagonists of 5-HT1A and 5-HT2A receptors, WAY-100635 and ketanserin, respectively, or systemic pretreatment with the 5-HT synthesis inhibitor p-CPA. RESULTS OT impaired escape expression in the two tests used, suggesting a panicolytic-like effect. In the ETM, the peptide also facilitated inhibitory avoidance acquisition, indicating an anxiogenic effect. Previous administration of atosiban, WAY-100635, ketanserin, or p-CPA counteracted OT's anti-escape effect. CONCLUSIONS OT and 5-HT in the dPAG interact in the regulation of panic- and anxiety-related defensive responses. These findings open new perspectives for the development of novel therapeutic strategies for the treatment of anxiety disorders.
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Affiliation(s)
- Thatiane De Oliveira Sergio
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | - Alana Tercino Frias
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | - Heloisa Helena Vilela-Costa
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | - Danielle Cg De Oliveira
- Department of Neurosciences and Behavior, Division of Psychiatry, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil
| | - Antônio W Zuardi
- Department of Neurosciences and Behavior, Division of Psychiatry, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil
| | - Hélio Zangrossi
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
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Hirota Y, Arai A, Young LJ, Osako Y, Yuri K, Mitsui S. Oxytocin receptor antagonist reverses the blunting effect of pair bonding on fear learning in monogamous prairie voles. Horm Behav 2020; 120:104685. [PMID: 31935400 PMCID: PMC7117995 DOI: 10.1016/j.yhbeh.2020.104685] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 12/20/2019] [Accepted: 12/31/2019] [Indexed: 01/31/2023]
Abstract
Social relationships among spouses, family members, and friends are known to affect physical and mental health. In particular, long-lasting bonds between socio-sexual partners have profound effects on cognitive, social, emotional, and physical well-being. We have previously reported that pair bonding in monogamous prairie voles (Microtus ochrogaster) is prevented by a single prolonged stress (SPS) paradigm, which causes behavioral and endocrine symptoms resembling post-traumatic stress disorder (PTSD) patients in rats (Arai et al., 2016). Since fear memory function is crucial for anxiety-related disorders such as PTSD, we investigated the effects of pair bonding on fear learning in prairie voles. We applied an SPS paradigm to male prairie voles after the cohabitation with a male (cage-mate group) or female (pair-bonded group). The cage-mate group, but not the pair-bonded group, showed enhanced fear response in a contextual fear conditioning test following the SPS treatment. Immunohistochemical analyses revealed that cFos-positive cells in the central amygdala were increased in the pair-bonded group after the contextual fear conditioning test and that oxytocin immunoreactivity in the paraventricular nucleus of the hypothalamus was significantly higher in the pair-bonded group than the cage-mate group. This pair-bonding dependent blunting of fear memory response was confirmed by a passive avoidance test, another fear-based learning test. Interestingly, intracerebroventricular injection of an oxytocin receptor antagonist 30 min before the passive avoidance test blocked the blunting effect of pair bonding on fear learning. Thus, pair bonding between socio-sexual partners results in social buffering in the absence of the partner, blunting fear learning, which may be mediated by oxytocin signaling.
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Affiliation(s)
- Yu Hirota
- Department of Rehabilitation Sciences, Gunma University Graduate School of Health Sciences, 3-39-22 Showa, Maebashi, Gunma 371-8514, Japan
| | - Aki Arai
- Department of Rehabilitation Sciences, Gunma University Graduate School of Health Sciences, 3-39-22 Showa, Maebashi, Gunma 371-8514, Japan
| | - Larry J Young
- Silvio O. Conte Center for Oxytocin and Social Cognition, Center for Translational Social Neuroscience, Department of Psychiatry and Behavioral Sciences, Yerkes National Primate Center, Emory University School of Medicine, 954 Gatewood Rd., Atlanta, GA 30329, USA; Center for Social Neural Networks, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Japan
| | - Yoji Osako
- Department of Neurobiology and Anatomy, Kochi Medical School, Kochi University, Oko-cho, Nankoku, Kochi 783-8505, Japan
| | - Kazunari Yuri
- Department of Neurobiology and Anatomy, Kochi Medical School, Kochi University, Oko-cho, Nankoku, Kochi 783-8505, Japan
| | - Shinichi Mitsui
- Department of Rehabilitation Sciences, Gunma University Graduate School of Health Sciences, 3-39-22 Showa, Maebashi, Gunma 371-8514, Japan.
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The Role of the Oxytocin System in Anxiety Disorders. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1191:103-120. [PMID: 32002925 DOI: 10.1007/978-981-32-9705-0_7] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Oxytocin, a neuropeptide synthesized by the hypothalamus, plays a central role in human social behavior, social cognition, anxiety, mood, stress modulation, and fear learning and extinction. The relationships between oxytocin and psychiatric disorders including depression, anxiety, schizophrenia, and autism spectrum disorder have been extensively studied. In this chapter, we focus on the current knowledge about oxytocin and anxiety disorder. We discuss the anxiolytic effects of oxytocin in preclinical and clinical findings, possible related neurobehavioral mechanisms (social cognition, fear learning, and extinction), related neurotransmitter and neuroendocrine systems (hypothalamus-pituitary-adrenal axis, serotoninergic, and GABAergic systems), and studies regarding plasma levels of oxytocin, genetic and epigenetic findings, and effects of intranasal oxytocin in DSM-5 anxiety disorder (primarily social anxiety disorder and separation anxiety disorder) patients.
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Effects of intraperitoneal and intracerebroventricular injections of oxytocin on social and emotional behaviors in pubertal male mice. Physiol Behav 2019; 212:112701. [DOI: 10.1016/j.physbeh.2019.112701] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 09/27/2019] [Accepted: 10/04/2019] [Indexed: 12/20/2022]
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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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31
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Demographic, sampling- and assay-related confounders of endogenous oxytocin concentrations: A systematic review and meta-analysis. Front Neuroendocrinol 2019; 54:100775. [PMID: 31351080 DOI: 10.1016/j.yfrne.2019.100775] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 07/22/2019] [Accepted: 07/23/2019] [Indexed: 11/22/2022]
Abstract
Studies on endogenous oxytocin concentrations are often criticized for the debatable comparability between specimens and the variation in reported values. We performed meta-regressions on k = 229 studies (n = 12 741 participants), testing whether specimen, extraction, sex, age, time of day, or fasting instructions influenced oxytocin measurements. Predicted oxytocin concentrations differed depending on specimen and extraction: Measurements were extremely high in unextracted blood, compared to extracted blood and other specimens. Measurements were higher in samples with more female participants and higher age. Instructions not to smoke before sampling were correlated with higher oxytocin in unextracted samples. There was no impact of instructions to refrain from eating, drinking, consume caffeine, alcohol or exercising. Oxytocin concentrations increased from morning to afternoon. Our results showed that oxytocin is differentially reflected in blood, saliva, urine and cerebrospinal fluid. Extraction impacts oxytocin measurements, particularly in blood. Considering relevant confounders might increase comparability between studies.
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Farley D, Piszczek Ł, Bąbel P. Why is running a marathon like giving birth? The possible role of oxytocin in the underestimation of the memory of pain induced by labor and intense exercise. Med Hypotheses 2019; 128:86-90. [PMID: 31203917 DOI: 10.1016/j.mehy.2019.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 04/14/2019] [Accepted: 05/10/2019] [Indexed: 01/09/2023]
Abstract
Pain can be overestimated, underestimated or reported accurately at recall. The way pain is remembered seems to depend on certain factors, including the type of pain or, in other words, its cause, the context, and the meaning it has for the person suffering from it. For instance, episodes of chronic pain, as well as pain related to surgery, are often overestimated at recall. Interestingly, research shows that pain induced by parturition or marathon running is often underestimated at recall despite the fact that both are not only physically grueling but also emotionally intense experiences. However, both processes can likewise be considered positive events, as opposed to most that involve pain. On the neurophysiological level, one of the similarities between giving birth and running a marathon is the particular involvement of the oxytocin system. Oxytocin is involved both in parturition and intense exercise, for various reasons. During labor, oxytocin mediates uterine contractions, while in the case of extensive running it might be involved in the maintenance of fluid balance. It also has well-documented analgesic properties and plays an important role in memory formation and recall. It has been suggested that oxytocin modulates the output of the central nucleus of the amygdala (CeA) during the fear recall. Moreover, it has been demonstrated that oxytocin can impair fear learning and influence the memory of both positive and negative emotionally salient stimuli. We propose that the reason for pain to be remembered in a more favorable light is the central action of oxytocin in the central nucleus of the amygdala, first and foremost during the encoding phase.
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Affiliation(s)
- Dominika Farley
- Jagiellonian University, Institute of Psychology, Pain Research Group, Poland.
| | | | - Przemysław Bąbel
- Jagiellonian University, Institute of Psychology, Pain Research Group, Poland
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Martinon D, Lis P, Roman AN, Tornesi P, Applebey SV, Buechner G, Olivera V, Dabrowska J. Oxytocin receptors in the dorsolateral bed nucleus of the stria terminalis (BNST) bias fear learning toward temporally predictable cued fear. Transl Psychiatry 2019; 9:140. [PMID: 31000694 PMCID: PMC6472379 DOI: 10.1038/s41398-019-0474-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 03/19/2019] [Accepted: 04/01/2019] [Indexed: 11/18/2022] Open
Abstract
The inability to discriminate between threat and safety is a hallmark of stress-induced psychiatric disorders, including post-traumatic stress disorder. Dorsolateral bed nucleus of the stria terminalis (BNSTdl) is critically involved in the modulation of fear and anxiety, and has been proposed to regulate discrimination between signaled (cued, predictable) and unsignaled (unpredictable) threats. We recently showed that oxytocin receptors (OTRs) in the BNSTdl facilitate acquisition of cued fear measured in a fear-potentiated startle (FPS). In the current study, using in vivo microdialysis in awake male Sprague-Dawley rats, a double immunofluorescence approach with confocal microscopy, as well as retrograde tracing of hypothalamic BNST-projecting OT neurons, we investigated whether fear conditioning activates OT system and modulates OT release. To determine the role of OTR in fear memory formation, we also infused OTR antagonist or OT into the BNSTdl before fear conditioning and measured rats' ability to discriminate between cued (signaled) and non-cued (unsignaled) fear using FPS. In contrast to acute stress (exposure to forced swim stress or foot shocks alone), cued fear conditioning increases OT content in BNSTdl microdialysates. In addition, fear conditioning induces moderate activation of OT neurons in the paraventricular nucleus of the hypothalamus and robust activation in the supraoptic and accessory nuclei of the hypothalamus. Application of OT into the BNSTdl facilitates fear learning toward signaled, predictable threats, whereas blocking OTR attenuates this effect. We conclude that OTR neurotransmission in the BNSTdl plays a pivotal role in strengthening fear learning of temporally predictable, signaled threats.
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Affiliation(s)
- Daisy Martinon
- 0000 0004 0388 7807grid.262641.5Department of Cellular and Molecular Pharmacology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064 USA
| | - Paulina Lis
- 0000 0004 0388 7807grid.262641.5Department of Cellular and Molecular Pharmacology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064 USA
| | - Alexandra N. Roman
- 0000 0004 0388 7807grid.262641.5Department of Cellular and Molecular Pharmacology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064 USA
| | - Patricio Tornesi
- 0000 0004 0388 7807grid.262641.5Department of Cellular and Molecular Pharmacology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064 USA
| | - Sarah V. Applebey
- 0000 0004 0388 7807grid.262641.5Department of Cellular and Molecular Pharmacology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064 USA
| | - Garrett Buechner
- 0000 0004 0388 7807grid.262641.5Department of Cellular and Molecular Pharmacology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064 USA
| | - Valentina Olivera
- 0000 0004 0388 7807grid.262641.5Department of Cellular and Molecular Pharmacology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064 USA ,0000 0004 0388 7807grid.262641.5Center for the Neurobiology of Stress Resilience and Psychiatric Disorders, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064 USA ,0000 0004 0388 7807grid.262641.5School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064 USA
| | - Joanna Dabrowska
- Department of Cellular and Molecular Pharmacology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, 60064, USA. .,Center for the Neurobiology of Stress Resilience and Psychiatric Disorders, Rosalind Franklin University of Medicine and Science, North Chicago, IL, 60064, USA. .,School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science, North Chicago, IL, 60064, USA.
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Onaka T, Takayanagi Y. Role of oxytocin in the control of stress and food intake. J Neuroendocrinol 2019; 31:e12700. [PMID: 30786104 PMCID: PMC7217012 DOI: 10.1111/jne.12700] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 02/12/2019] [Accepted: 02/15/2019] [Indexed: 12/20/2022]
Abstract
Oxytocin neurones in the hypothalamus are activated by stressful stimuli and food intake. The oxytocin receptor is located in various brain regions, including the sensory information-processing cerebral cortex; the cognitive information-processing prefrontal cortex; reward-related regions such as the ventral tegmental areas, nucleus accumbens and raphe nucleus; stress-related areas such as the amygdala, hippocampus, ventrolateral part of the ventromedial hypothalamus and ventrolateral periaqueductal gray; homeostasis-controlling hypothalamus; and the dorsal motor complex controlling intestinal functions. Oxytocin affects behavioural and neuroendocrine stress responses and terminates food intake by acting on the metabolic or nutritional homeostasis system, modulating emotional processing, reducing reward values of food intake, and facilitating sensory and cognitive processing via multiple brain regions. Oxytocin also plays a role in interactive actions between stress and food intake and contributes to adaptive active coping behaviours.
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Affiliation(s)
- Tatsushi Onaka
- Division of Brain and NeurophysiologyDepartment of PhysiologyJichi Medical UniversityShimotsuke‐shiJapan
| | - Yuki Takayanagi
- Division of Brain and NeurophysiologyDepartment of PhysiologyJichi Medical UniversityShimotsuke‐shiJapan
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35
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Freeman AR, Hare JF, Caldwell HK. Central distribution of oxytocin and vasopressin 1a receptors in juvenile Richardson's ground squirrels. J Neurosci Res 2019; 97:772-789. [PMID: 30802986 DOI: 10.1002/jnr.24400] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 01/15/2019] [Accepted: 01/31/2019] [Indexed: 12/30/2022]
Abstract
Oxytocin and vasopressin are well-conserved peptides important to the regulation of numerous aspects of social behavior, including sociality. Research exploring the distribution of the receptors for oxytocin (Oxtr) and for vasopressin (Avpr1a) in mammals has revealed associations between receptor distribution, sociality, and species' mating systems. Given that sociality and gregariousness can be tightly linked to reproduction, these nonapeptides unsurprisingly support affiliative behaviors that are important for mating and offspring care. We localized these receptors in juvenile Richardson's ground squirrel brains to determine whether distribution patterns of Oxtr and Avpr1a that are associated with promiscuous mating systems differ in rodents that also exhibit non-reproductive affiliation. These squirrels are social, colonial, and engage in nepotistic alarm calling behavior and affiliation outside of a reproductive context. Juveniles are the most affiliative age-class and are non-reproductive; making them ideal for examining these associations. We found that juveniles had dense Oxtr binding in the dentate gyrus of the hippocampus, amygdala, lateral septum, bed nucleus of the stria terminalis and medial geniculate nucleus. Juveniles had low to modest levels of Avpr1a binding in the medial preoptic area, olfactory bulbs, nucleus accumbens, superior colliculus, and inferior colliculus. We noted Oxtr and Avpr1a binding in the social behavior neural network (SBNN), further supporting a role of these nonapeptides in modulating social behavior across taxa. Oxtr and Avpr1a binding was also present in brain regions important to auditory processing that have known projections to the SBNN. We speculate that these neural substrates may be where these nonapeptides regulate communication.
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Affiliation(s)
- Angela R Freeman
- Laboratory of Neuroendocrinology and Behavior, Department of Biological Sciences, Kent State University, Kent, Ohio
| | - James F Hare
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Heather K Caldwell
- Laboratory of Neuroendocrinology and Behavior, Department of Biological Sciences, Kent State University, Kent, Ohio.,School of Biomedical Sciences, Kent State University, Kent, Ohio
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36
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Oxytocin for learning calm and safety. Int J Psychophysiol 2019; 136:5-14. [DOI: 10.1016/j.ijpsycho.2018.06.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 06/21/2018] [Accepted: 06/26/2018] [Indexed: 12/22/2022]
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Acute and long-lasting effects of oxytocin in cortico-limbic circuits: consequences for fear recall and extinction. Psychopharmacology (Berl) 2019; 236:339-354. [PMID: 30302511 DOI: 10.1007/s00213-018-5030-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 09/05/2018] [Indexed: 12/11/2022]
Abstract
The extinction of conditioned fear responses entrains the formation of safe new memories to decrease those behavioral responses. The knowledge in neuronal mechanisms of extinction is fundamental in the treatment of anxiety and fear disorders. Interestingly, the use of pharmacological compounds that reduce anxiety and fear has been shown as a potent co-adjuvant in extinction therapy. However, the efficiency and mechanisms by which pharmacological compounds promote extinction of fear memories remains still largely unknown and would benefit from a validation based on functional neuronal circuits, and the neurotransmitters that modulate them. From this perspective, oxytocin receptor signaling, which has been shown in cortical and limbic areas to modulate numerous functions (Eliava et al. Neuron 89(6):1291-1304, 2016), among them fear and anxiety circuits, and to enhance the salience of social stimuli (Stoop Neuron 76(1):142-59, 2012), may offer an interesting perspective. Experiments in animals and humans suggest that oxytocin could be a promising pharmacological agent at adjusting memory consolidation to boost fear extinction. Additionally, it is possible that long-term changes in endogenous oxytocin signaling can also play a role in reducing expression of fear at different brain targets. In this review, we summarize the effects reported for oxytocin in cortico-limbic circuits and on fear behavior that are of relevance for the modulation and potential extinction of fear memories.
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Hu J, Wang Z, Feng X, Long C, Schiller D. Post-retrieval oxytocin facilitates next day extinction of threat memory in humans. Psychopharmacology (Berl) 2019; 236:293-301. [PMID: 30370450 PMCID: PMC6374199 DOI: 10.1007/s00213-018-5074-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 10/10/2018] [Indexed: 01/28/2023]
Abstract
RATIONALE Memories can return to a labile state and become amenable to modification by pharmacological and behavioral manipulations after retrieval. This process may reduce the impact of aversive memories and provide a promising therapeutic technique for the treatment of anxiety disorders. A growing body of evidence suggests that the mammalian neuropeptide oxytocin (OT) plays a role in the regulation of emotional memories in animals. However, the effects of OT on threat memory in humans remain largely unknown. OBJECTIVES This study aimed to investigate the effects of OT administration following threat memory retrieval on subsequent memory expression in human participants. METHODS In a double-blind, randomized, placebo-controlled, between-subject design, 61 healthy human individuals completed a 3-day experiment. All the participants underwent threat conditioning on day 1. On day 2, the participants were randomized to receive an intranasal dose of OT (40 IU) or placebo after memory retrieval, or an intranasal dose of OT (40 IU) without retrieval. On day 3, the participants were tested for extinction and reinstatement. RESULTS On day 3, all groups showed equivalent stimulus discrimination during the early phase of extinction. However, the group that received OT following a memory reminder showed a greater decline in stimulus discrimination by the late phase of extinction relative to the two other groups. CONCLUSIONS The results indicate that OT did not block reconsolidation to prevent the return of threat memory but rather interacted with post-retrieval processes to facilitate next day extinction. The study provides novel preliminary evidence for the role of OT in human threat memory.
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Affiliation(s)
- Jingchu Hu
- School of Life Sciences, South China Normal University, Guangzhou, China,School of Psychology and Center for Studies of Psychological Application, South China Normal University, Guangzhou, China
| | - Zijie Wang
- School of Psychology and Center for Studies of Psychological Application, South China Normal University, Guangzhou, China
| | - Xiaoyi Feng
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Cheng Long
- School of Life Sciences, South China Normal University, Guangzhou, China.
| | - Daniela Schiller
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA. .,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA. .,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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39
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D'Souza MS. Brain and Cognition for Addiction Medicine: From Prevention to Recovery Neural Substrates for Treatment of Psychostimulant-Induced Cognitive Deficits. Front Psychiatry 2019; 10:509. [PMID: 31396113 PMCID: PMC6667748 DOI: 10.3389/fpsyt.2019.00509] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 06/28/2019] [Indexed: 01/10/2023] Open
Abstract
Addiction to psychostimulants like cocaine, methamphetamine, and nicotine poses a continuing medical and social challenge both in the United States and all over the world. Despite a desire to quit drug use, return to drug use after a period of abstinence is a common problem among individuals dependent on psychostimulants. Recovery for psychostimulant drug-dependent individuals is particularly challenging because psychostimulant drugs induce significant changes in brain regions associated with cognitive functions leading to cognitive deficits. These cognitive deficits include impairments in learning/memory, poor decision making, and impaired control of behavioral output. Importantly, these drug-induced cognitive deficits often impact adherence to addiction treatment programs and predispose abstinent addicts to drug use relapse. Additionally, these cognitive deficits impact effective social and professional rehabilitation of abstinent addicts. The goal of this paper is to review neural substrates based on animal studies that could be pharmacologically targeted to reverse psychostimulant-induced cognitive deficits such as impulsivity and impairment in learning and memory. Further, the review will discuss neural substrates that could be used to facilitate extinction learning and thus reduce emotional and behavioral responses to drug-associated cues. Moreover, the review will discuss some non-pharmacological approaches that could be used either alone or in combination with pharmacological compounds to treat the above-mentioned cognitive deficits. Psychostimulant addiction treatment, which includes treatment for cognitive deficits, will help promote abstinence and allow for better rehabilitation and integration of abstinent individuals into society.
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Affiliation(s)
- Manoranjan S D'Souza
- Department of Pharmaceutical and Biomedical Sciences, The Raabe College of Pharmacy, Ohio Northern University, Ada, OH, United States
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Intranasal oxytocin administration promotes emotional contagion and reduces aggression in a mouse model of callousness. Neuropharmacology 2018; 143:250-267. [DOI: 10.1016/j.neuropharm.2018.09.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 09/06/2018] [Accepted: 09/08/2018] [Indexed: 12/30/2022]
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Janeček M, Dabrowska J. Oxytocin facilitates adaptive fear and attenuates anxiety responses in animal models and human studies-potential interaction with the corticotropin-releasing factor (CRF) system in the bed nucleus of the stria terminalis (BNST). Cell Tissue Res 2018; 375:143-172. [PMID: 30054732 DOI: 10.1007/s00441-018-2889-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 07/04/2018] [Indexed: 01/28/2023]
Abstract
Despite its relatively well-understood role as a reproductive and pro-social peptide, oxytocin (OT) tells a more convoluted story in terms of its modulation of fear and anxiety. This nuanced story has been obscured by a great deal of research into the therapeutic applications of exogenous OT, driving more than 400 ongoing clinical trials. Drawing from animal models and human studies, we review the complex evidence concerning OT's role in fear learning and anxiety, clarifying the existing confusion about modulation of fear versus anxiety. We discuss animal models and human studies demonstrating the prevailing role of OT in strengthening fear memory to a discrete signal or cue, which allows accurate and rapid threat detection that facilitates survival. We also review ostensibly contrasting behavioral studies that nonetheless provide compelling evidence of OT attenuating sustained contextual fear and anxiety-like behavior, arguing that these OT effects on the modulation of fear vs. anxiety are not mutually exclusive. To disambiguate how endogenous OT modulates fear and anxiety, an understudied area compared to exogenous OT, we survey behavioral studies utilizing OT receptor (OTR) antagonists. Based on emerging evidence about the role of OTR in rat dorsolateral bed nucleus of stria terminalis (BNST) and elsewhere, we postulate that OT plays a critical role in facilitating accurate discrimination between stimuli representing threat and safety. Supported by human studies, we demonstrate that OT uniquely facilitates adaptive fear but reduces maladaptive anxiety. Last, we explore the limited literature on endogenous OT and its interaction with corticotropin-releasing factor (CRF) with a special emphasis on the dorsolateral BNST, which may hold the key to the neurobiology of phasic fear and sustained anxiety.
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Affiliation(s)
- Michael Janeček
- Department of Cellular and Molecular Pharmacology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, 60064, USA
| | - Joanna Dabrowska
- Department of Cellular and Molecular Pharmacology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, 60064, USA. .,Department of Neuroscience, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, 60064, USA.
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42
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Jurek B, Neumann ID. The Oxytocin Receptor: From Intracellular Signaling to Behavior. Physiol Rev 2018; 98:1805-1908. [DOI: 10.1152/physrev.00031.2017] [Citation(s) in RCA: 408] [Impact Index Per Article: 68.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The many facets of the oxytocin (OXT) system of the brain and periphery elicited nearly 25,000 publications since 1930 (see FIGURE 1 , as listed in PubMed), which revealed central roles for OXT and its receptor (OXTR) in reproduction, and social and emotional behaviors in animal and human studies focusing on mental and physical health and disease. In this review, we discuss the mechanisms of OXT expression and release, expression and binding of the OXTR in brain and periphery, OXTR-coupled signaling cascades, and their involvement in behavioral outcomes to assemble a comprehensive picture of the central and peripheral OXT system. Traditionally known for its role in milk let-down and uterine contraction during labor, OXT also has implications in physiological, and also behavioral, aspects of reproduction, such as sexual and maternal behaviors and pair bonding, but also anxiety, trust, sociability, food intake, or even drug abuse. The many facets of OXT are, on a molecular basis, brought about by a single receptor. The OXTR, a 7-transmembrane G protein-coupled receptor capable of binding to either Gαior Gαqproteins, activates a set of signaling cascades, such as the MAPK, PKC, PLC, or CaMK pathways, which converge on transcription factors like CREB or MEF-2. The cellular response to OXT includes regulation of neurite outgrowth, cellular viability, and increased survival. OXTergic projections in the brain represent anxiety and stress-regulating circuits connecting the paraventricular nucleus of the hypothalamus, amygdala, bed nucleus of the stria terminalis, or the medial prefrontal cortex. Which OXT-induced patterns finally alter the behavior of an animal or a human being is still poorly understood, and studying those OXTR-coupled signaling cascades is one initial step toward a better understanding of the molecular background of those behavioral effects.
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Affiliation(s)
- Benjamin Jurek
- Department of Behavioural and Molecular Neurobiology, Institute of Zoology, University of Regensburg, Regensburg, Germany
| | - Inga D. Neumann
- Department of Behavioural and Molecular Neurobiology, Institute of Zoology, University of Regensburg, Regensburg, Germany
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Beneficial effects of chronic oxytocin administration and social co-housing in a rodent model of post-traumatic stress disorder. Behav Pharmacol 2018; 27:704-717. [PMID: 27740964 DOI: 10.1097/fbp.0000000000000270] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Post-traumatic stress disorder (PTSD) is in part due to a deficit in memory consolidation and extinction. Oxytocin (OXT) has anxiolytic effects and promotes prosocial behaviors in both rodents and humans, and evidence suggests that it plays a role in memory consolidation. We studied the effects of administered OXT and social co-housing in a rodent model of PTSD. Acute OXT yielded a short-term increase in the recall of the traumatic memory if administered immediately after trauma. Low doses of OXT delivered chronically had a cumulating anxiolytic effect that became apparent after 4 days and persisted. Repeated injections of OXT after short re-exposures to the trauma apparatus yielded a long-term reduction in anxiety. Co-housing with naive nonshocked animals decreased the memory of the traumatic context compared with single-housed animals. In the long term, these animals showed less thigmotaxis and increased interest in novel objects, and a low OXT plasma level. Co-housed PTSD animals showed an increase in risk-taking behavior. These results suggest beneficial effects of OXT if administered chronically through increases in memory consolidation after re-exposure to a safe trauma context. We also show differences between the benefits of social co-housing with naive rats and co-housing with other shocked animals on trauma-induced long-term anxiety.
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Kritman M, Maroun M. Toward Comprehensive Understanding of the Effects of Intranasal Oxytocin on the Human Amygdala. Biol Psychiatry 2017; 82:864-865. [PMID: 29129200 DOI: 10.1016/j.biopsych.2017.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 09/30/2017] [Indexed: 11/26/2022]
Affiliation(s)
- Milly Kritman
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel
| | - Mouna Maroun
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel.
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Abstract
Empathy is fundamental to human relations, but its neural substrates remain largely unknown. Here we characterize the involvement of oxytocin in the capacity of mice to display emotional state-matching, an empathy-like behavior. When exposed to a familiar conspecific demonstrator in distress, an observer mouse becomes fearful, as indicated by a tendency to freeze and subsequent efforts to escape. Both intranasal oxytocin administration and chemogenetic stimulation of oxytocin neurons render males sensitive to the distress of an unfamiliar mouse. Acute intranasal oxytocin penetrates the brain and enhances cellular activity within the anterior cingulate cortex, whereas chronic administration produces long-term facilitation of observational fear and downregulates oxytocin receptor expression in the amygdala. None of these manipulations affect fear acquired as a result of direct experience with the stressor. Hence, these results implicate oxytocin in observational fear in mice (rather than fear itself) and provide new avenues for examining the neural substrates of empathy. Oxytocin modulates social behaviours in mammals. Here the authors demonstrate that observational fear, a measure of empathy-like behaviour in rodents, is modulated by oxytocin.
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Abstract
PURPOSE OF REVIEW This review aims to evaluate the most recent literature examining the oxytocin (OXT) system's role in human anxiety by surveying various fields of preclinical and clinical research supporting this role, and queries whether the OXT system might be a target for novel anxiolytics. RECENT FINDINGS Evidence from the diverse body of literature presented here, from translational research, genetic and neuroimaging studies, to clinical trials of intranasal (IN) OXT reveals a positive association. In addition, some moderators (e.g., sex, specificities to cues) of OXT's anxiolytic effects can have an important influence on its outcomes, awaiting further research. Evidence for the role of OXT in regulating anxiety is undeniable. We expect that the diverse particularities of the OXT system will help broaden our understanding of anxiety and stress-related disorders. We conclude that OXT promises an enticing treatment option for human anxiety disorders especially those associated with socio-emotional dysfunctions.
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Affiliation(s)
- Wadih Jean Naja
- Department of Psychiatry, Lebanese University, Beirut, Lebanon. .,Gharios Medical Center, Mount Lebanon Hospital, Hazmieh, Beirut, Lebanon.
| | - Michaelangelo Pietro Aoun
- Department of Psychiatry, Lebanese University, Beirut, Lebanon.,Gharios Medical Center, Mount Lebanon Hospital, Hazmieh, Beirut, Lebanon
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Moaddab M, Dabrowska J. Oxytocin receptor neurotransmission in the dorsolateral bed nucleus of the stria terminalis facilitates the acquisition of cued fear in the fear-potentiated startle paradigm in rats. Neuropharmacology 2017; 121:130-139. [PMID: 28456687 PMCID: PMC5553312 DOI: 10.1016/j.neuropharm.2017.04.039] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 04/04/2017] [Accepted: 04/25/2017] [Indexed: 01/25/2023]
Abstract
Oxytocin (OT) is a hypothalamic neuropeptide that modulates fear and anxiety-like behaviors. Dorsolateral bed nucleus of the stria terminalis (BNSTdl) plays a critical role in the regulation of fear and anxiety, and expresses high levels of OT receptor (OTR). However, the role of OTR neurotransmission within the BNSTdl in mediating these behaviors is unknown. Here, we used adult male Sprague-Dawley rats to investigate the role of OTR neurotransmission in the BNSTdl in the modulation of the acoustic startle response, as well as in the acquisition and consolidation of conditioned fear using fear potentiated startle (FPS) paradigm. Bilateral intra-BNSTdl administration of OT (100 ng) did not affect the acquisition of conditioned fear response. However, intra-BNSTdl administration of specific OTR antagonist (OTA), (d(CH2)51, Tyr(Me)2, Thr4, Orn8, des-Gly-NH29)-vasotocin, (200 ng), prior to the fear conditioning session, impaired the acquisition of cued fear, without affecting a non-cued fear component of FPS. Neither OTA, nor OT affected baseline startle or shock reactivity during fear conditioning. Therefore, the observed impairment of cued fear after OTA infusion resulted from the specific effect on the formation of cued fear. In contrast to the acquisition, neither OTA nor OT affected the consolidation of FPS, when administered after the completion of fear conditioning session. Taken together, these results reveal the important role of OTR neurotransmission in the BNSTdl in the formation of conditioned fear to a discrete cue. This study also highlights the role of the BNSTdl in learning to discriminate between threatening and safe stimuli.
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Affiliation(s)
- Mahsa Moaddab
- Department of Cellular and Molecular Pharmacology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Joanna Dabrowska
- Department of Cellular and Molecular Pharmacology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA; Department of Neuroscience, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA.
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Sabihi S, Dong SM, Maurer SD, Post C, Leuner B. Oxytocin in the medial prefrontal cortex attenuates anxiety: Anatomical and receptor specificity and mechanism of action. Neuropharmacology 2017; 125:1-12. [PMID: 28655609 DOI: 10.1016/j.neuropharm.2017.06.024] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 06/21/2017] [Accepted: 06/23/2017] [Indexed: 01/12/2023]
Abstract
Numerous studies in animals and humans have established that oxytocin (OT) reduces anxiety. In rats, the prelimbic (PL) subregion of the medial prefrontal cortex (mPFC) is among the brain areas implicated in the anxiolytic actions of OT. However, questions remain about the anatomical and receptor specificity of OT and its mechanism of action. Here we assessed whether the regulation of anxiety by mPFC OT is restricted to the PL subregion and evaluated whether oxytocin receptor (OTR) activation is required for OT to have an anxiolytic effect. We also examined whether OT interacts with GABA in the mPFC to reduce anxiety and investigated the extent to which OT in the mPFC affects activation of mPFC GABA neurons as well as neuronal activation in the amygdala, a primary target of the mPFC which is part of the neural network regulating anxiety. We found that OT reduced anxiety-like behavior when delivered to the PL, but not infralimbic or anterior cingulate subregions of the mPFC. The anxiolytic effect of OT in the PL mPFC was blocked by pretreatment with an OTR, but not a vasopressin receptor, antagonist as well as with a GABAA receptor antagonist. Lastly, administration of OT to the PL mPFC was accompanied by increased activation of GABA neurons in the PL mPFC and altered neuronal activation of the amygdala following anxiety testing. These results demonstrate that OT in the PL mPFC attenuates anxiety-related behavior and may do so by engaging GABAergic neurons which ultimately modulate downstream brain regions implicated in anxiety.
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Affiliation(s)
- Sara Sabihi
- The Ohio State University, Department of Psychology, Columbus, OH 43210, United States
| | - Shirley M Dong
- The Ohio State University, Department of Psychology, Columbus, OH 43210, United States
| | - Skyler D Maurer
- The Ohio State University, Department of Psychology, Columbus, OH 43210, United States
| | - Caitlin Post
- The Ohio State University, Department of Psychology, Columbus, OH 43210, United States
| | - Benedetta Leuner
- The Ohio State University, Department of Psychology, Columbus, OH 43210, United States; The Ohio State University, Department of Neuroscience, Columbus, OH 43210, United States; The Ohio State University, Behavioral Neuroendocrinology Group, Columbus, OH 43210, United States.
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Oxytocin in the amygdala and not the prefrontal cortex enhances fear and impairs extinction in the juvenile rat. Neurobiol Learn Mem 2017; 141:179-188. [DOI: 10.1016/j.nlm.2017.04.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 03/31/2017] [Accepted: 04/03/2017] [Indexed: 01/06/2023]
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Martin S. Journal Watch review of Oxytocin and memory of emotional stimuli: Some dance to remember, some dance to forget. J Am Psychoanal Assoc 2016; 64:822-6. [PMID: 27609079 DOI: 10.1177/0003065116667292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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