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Lauretani F, Giallauria F, Testa C, Zinni C, Lorenzi B, Zucchini I, Salvi M, Napoli R, Maggio MG. Dopamine Pharmacodynamics: New Insights. Int J Mol Sci 2024; 25:5293. [PMID: 38791331 PMCID: PMC11121567 DOI: 10.3390/ijms25105293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2024] [Revised: 05/04/2024] [Accepted: 05/07/2024] [Indexed: 05/26/2024] Open
Abstract
Dopamine is a key neurotransmitter involved in physiological processes such as motor control, motivation, reward, cognitive function, and maternal and reproductive behaviors. Therefore, dysfunctions of the dopaminergic system are related to a plethora of human diseases. Dopamine, via different circuitries implicated in compulsive behavior, reward, and habit formation, also represents a key player in substance use disorder and the formation and perpetuation of mechanisms leading to addiction. Here, we propose dopamine as a model not only of neurotransmission but also of neuromodulation capable of modifying neuronal architecture. Abuse of substances like methamphetamine, cocaine, and alcohol and their consumption over time can induce changes in neuronal activities. These modifications lead to synaptic plasticity and finally to morphological and functional changes, starting from maladaptive neuro-modulation and ending in neurodegeneration.
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Affiliation(s)
- Fulvio Lauretani
- Geriatric Clinic Unit, Geriatric-Rehabilitation Department, University Hospital, 43126 Parma, Italy; (C.T.); (C.Z.); (B.L.); (I.Z.); (M.S.); (M.G.M.)
- Cognitive and Motor Center, Medicine and Geriatric-Rehabilitation Department of Parma, University-Hospital of Parma, 43126 Parma, Italy
| | - Francesco Giallauria
- Department of Translational Medical Sciences, “Federico II” University of Naples, via S. Pansini 5, 80131 Naples, Italy; (F.G.); (R.N.)
| | - Crescenzo Testa
- Geriatric Clinic Unit, Geriatric-Rehabilitation Department, University Hospital, 43126 Parma, Italy; (C.T.); (C.Z.); (B.L.); (I.Z.); (M.S.); (M.G.M.)
| | - Claudia Zinni
- Geriatric Clinic Unit, Geriatric-Rehabilitation Department, University Hospital, 43126 Parma, Italy; (C.T.); (C.Z.); (B.L.); (I.Z.); (M.S.); (M.G.M.)
| | - Beatrice Lorenzi
- Geriatric Clinic Unit, Geriatric-Rehabilitation Department, University Hospital, 43126 Parma, Italy; (C.T.); (C.Z.); (B.L.); (I.Z.); (M.S.); (M.G.M.)
| | - Irene Zucchini
- Geriatric Clinic Unit, Geriatric-Rehabilitation Department, University Hospital, 43126 Parma, Italy; (C.T.); (C.Z.); (B.L.); (I.Z.); (M.S.); (M.G.M.)
| | - Marco Salvi
- Geriatric Clinic Unit, Geriatric-Rehabilitation Department, University Hospital, 43126 Parma, Italy; (C.T.); (C.Z.); (B.L.); (I.Z.); (M.S.); (M.G.M.)
| | - Raffaele Napoli
- Department of Translational Medical Sciences, “Federico II” University of Naples, via S. Pansini 5, 80131 Naples, Italy; (F.G.); (R.N.)
| | - Marcello Giuseppe Maggio
- Geriatric Clinic Unit, Geriatric-Rehabilitation Department, University Hospital, 43126 Parma, Italy; (C.T.); (C.Z.); (B.L.); (I.Z.); (M.S.); (M.G.M.)
- Cognitive and Motor Center, Medicine and Geriatric-Rehabilitation Department of Parma, University-Hospital of Parma, 43126 Parma, Italy
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Barenz J, O'Donnell M, Smith J. The Endogenous Opioid System as a Pathway of Positive Emotions. ADVANCES IN NEUROBIOLOGY 2024; 35:241-250. [PMID: 38874726 DOI: 10.1007/978-3-031-45493-6_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2024]
Abstract
Pleasant emotions take a variety of forms and are a key part of the human experience. Although negative emotions have often been a focus of research, positive emotions, e.g., joy, pleasure, and love, have recently gained more attention. Each of these emotions is rich and complex in its own right. However, positive emotions appear to serve key evolutionary functions, which are mediated by complex biological substrates. This chapter summarizes key research and explores the biological underpinnings of positive emotions, with an emphasis on the roles that endogenous opioids play in the experience, expression, and development of positive emotions. The necessity of emphasizing positive emotions in research is also discussed.
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Affiliation(s)
| | - Maeve O'Donnell
- Seattle Children's & University of Washington School of Medicine, Seattle, WA, USA
| | - Joey Smith
- Colorado State University, Fort Collins, CO, USA
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3
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Al‐Alsheikh AS, Alabdulkader S, Miras AD, Goldstone AP. Effects of bariatric surgery and dietary interventions for obesity on brain neurotransmitter systems and metabolism: A systematic review of positron emission tomography (PET) and single-photon emission computed tomography (SPECT) studies. Obes Rev 2023; 24:e13620. [PMID: 37699864 PMCID: PMC10909448 DOI: 10.1111/obr.13620] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 04/05/2023] [Accepted: 07/10/2023] [Indexed: 09/14/2023]
Abstract
This systematic review collates studies of dietary or bariatric surgery interventions for obesity using positron emission tomography and single-photon emission computed tomography. Of 604 publications identified, 22 met inclusion criteria. Twelve studies assessed bariatric surgery (seven gastric bypass, five gastric bypass/sleeve gastrectomy), and ten dietary interventions (six low-calorie diet, three very low-calorie diet, one prolonged fasting). Thirteen studies examined neurotransmitter systems (six used tracers for dopamine DRD2/3 receptors: two each for 11 C-raclopride, 18 F-fallypride, 123 I-IBZM; one for dopamine transporter, 123 I-FP-CIT; one used tracer for serotonin 5-HT2A receptor, 18 F-altanserin; two used tracers for serotonin transporter, 11 C-DASB or 123 I-FP-CIT; two used tracer for μ-opioid receptor, 11 C-carfentanil; one used tracer for noradrenaline transporter, 11 C-MRB); seven studies assessed glucose uptake using 18 F-fluorodeoxyglucose; four studies assessed regional cerebral blood flow using 15 O-H2 O (one study also used arterial spin labeling); and two studies measured fatty acid uptake using 18 F-FTHA and one using 11 C-palmitate. The review summarizes findings and correlations with clinical outcomes, eating behavior, and mechanistic mediators. The small number of studies using each tracer and intervention, lack of dietary intervention control groups in any surgical studies, heterogeneity in time since intervention and degree of weight loss, and small sample sizes hindered the drawing of robust conclusions across studies.
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Affiliation(s)
- Alhanouf S. Al‐Alsheikh
- Department of Metabolism, Digestion and Reproduction, Imperial College LondonHammersmith HospitalLondonUK
- Department of Community Health Sciences, College of Applied Medical SciencesKing Saud UniversityRiyadhSaudi Arabia
| | - Shahd Alabdulkader
- Department of Metabolism, Digestion and Reproduction, Imperial College LondonHammersmith HospitalLondonUK
- Department of Health Sciences, College of Health and Rehabilitation SciencesPrincess Nourah Bint Abdulrahman UniversityRiyadhSaudi Arabia
| | - Alexander D. Miras
- Department of Metabolism, Digestion and Reproduction, Imperial College LondonHammersmith HospitalLondonUK
- School of Medicine, Faculty of Life and Health SciencesUlster UniversityLondonderryUK
| | - Anthony P. Goldstone
- PsychoNeuroEndocrinology Research Group, Division of Psychiatry, Department of Brain Sciences, Imperial College LondonHammersmith HospitalLondonUK
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Dharavath RN, Pina-Leblanc C, Tang VM, Sloan ME, Nikolova YS, Pangarov P, Ruocco AC, Shield K, Voineskos D, Blumberger DM, Boileau I, Bozinoff N, Gerretsen P, Vieira E, Melamed OC, Sibille E, Quilty LC, Prevot TD. GABAergic signaling in alcohol use disorder and withdrawal: pathological involvement and therapeutic potential. Front Neural Circuits 2023; 17:1218737. [PMID: 37929054 PMCID: PMC10623140 DOI: 10.3389/fncir.2023.1218737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 09/04/2023] [Indexed: 11/07/2023] Open
Abstract
Alcohol is one of the most widely used substances. Alcohol use accounts for 5.1% of the global disease burden, contributes substantially to societal and economic costs, and leads to approximately 3 million global deaths yearly. Alcohol use disorder (AUD) includes various drinking behavior patterns that lead to short-term or long-lasting effects on health. Ethanol, the main psychoactive molecule acting in alcoholic beverages, directly impacts the GABAergic system, contributing to GABAergic dysregulations that vary depending on the intensity and duration of alcohol consumption. A small number of interventions have been developed that target the GABAergic system, but there are promising future therapeutic avenues to explore. This review provides an overview of the impact of alcohol on the GABAergic system, the current interventions available for AUD that target the GABAergic system, and the novel interventions being explored that in the future could be included among first-line therapies for the treatment of AUD.
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Affiliation(s)
| | - Celeste Pina-Leblanc
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
| | - Victor M. Tang
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Addiction Division, CAMH, Toronto, ON, Canada
- Division of Neurosciences and Clinical Translation, Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
- Institute of Mental Health Policy Research, CAMH, Toronto, ON, Canada
| | - Matthew E. Sloan
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
- Addiction Division, CAMH, Toronto, ON, Canada
- Division of Neurosciences and Clinical Translation, Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Department of Psychological Clinical Science, University of Toronto Scarborough, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
- Institute of Mental Health Policy Research, CAMH, Toronto, ON, Canada
| | - Yuliya S. Nikolova
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Peter Pangarov
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
| | - Anthony C. Ruocco
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Temerty Centre for Therapeutic Brain Intervention, CAMH, Toronto, ON, Canada
- Department of Psychology, University of Toronto Scarborough, Toronto, ON, Canada
| | - Kevin Shield
- Institute of Mental Health Policy Research, CAMH, Toronto, ON, Canada
| | - Daphne Voineskos
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Temerty Centre for Therapeutic Brain Intervention, CAMH, Toronto, ON, Canada
| | - Daniel M. Blumberger
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Temerty Centre for Therapeutic Brain Intervention, CAMH, Toronto, ON, Canada
| | - Isabelle Boileau
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Brain Health Imaging Centre, CAMH, Toronto, ON, Canada
| | - Nikki Bozinoff
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Family and Community Medicine, University of Toronto, Toronto, ON, Canada
| | - Philip Gerretsen
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
- Brain Health Imaging Centre, CAMH, Toronto, ON, Canada
| | - Erica Vieira
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Osnat C. Melamed
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Family and Community Medicine, University of Toronto, Toronto, ON, Canada
| | - Etienne Sibille
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Lena C. Quilty
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Thomas D. Prevot
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
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Bozkurt A, Balta S. The effect of methylphenidate on pain perception thresholds in children with attention deficit hyperactivity disorder. Child Adolesc Psychiatry Ment Health 2023; 17:118. [PMID: 37833816 PMCID: PMC10576289 DOI: 10.1186/s13034-023-00667-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 10/02/2023] [Indexed: 10/15/2023] Open
Abstract
BACKGROUND Pain perception is important in children with attention deficit hyperactivity disorder (ADHD) since they are more likely to experience painful events due to increased accident rates. The aim of this study is to contribute to the literature concerning the relationship between ADHD diagnosis, methylphenidate (MPH) therapy, and pain thresholds, since findings regarding the change in pain perception in children with ADHD are scarce and inconsistent. METHODS Children aged 8-13 years constituted both the ADHD group (n = 82) and the healthy controls (n = 41). The ADHD group was divided into two subgroups, ADHD without MPH (not treated pharmacologically) and ADHD with MPH (treated pharmacologically for at least three-months). The Conners' Parent Rating Scale-Revised: Short Form was employed to assess ADHD, a visual analog scale was applied to evaluate chronic pain severity, and a manual pressure algometer was used to assess pain thresholds. RESULT Children with ADHD had lower pain thresholds than the healthy controls (P < 0.05). However, lower regional pain thresholds were observed in the ADHD group without MPH compared to both the healthy control and ADHD with MPH groups. Although pain thresholds in the ADHD with MPH group were regionally lower than in the healthy controls, low pain thresholds were found in fewer regions compared to the ADHD without MPH group. CONCLUSIONS Children with ADHD are more sensitive to pain sensation, and MPH may help normalize these individuals' pain experiences by raising pain thresholds. Families and clinicians must be aware of situations that may cause pain in children with ADHD. In addition, these children's low threshold for pain may lead them to experience it more intensely.
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Affiliation(s)
- Abdullah Bozkurt
- Department of Child and Adolescent Psychiatry, Ataturk University, Erzurum, Turkey.
| | - Selin Balta
- Department of Pain Medicine, University of Health Sciences, Konya, Turkey
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Shatalina E, Ashok AH, Wall MB, Nour MM, Myers J, Reis Marques T, Rabiner EA, Howes OD. Reward processing in schizophrenia and its relation to Mu opioid receptor availability and negative symptoms: A [ 11C]-carfentanil PET and fMRI study. Neuroimage Clin 2023; 39:103481. [PMID: 37517175 PMCID: PMC10400918 DOI: 10.1016/j.nicl.2023.103481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 05/17/2023] [Accepted: 07/23/2023] [Indexed: 08/01/2023]
Abstract
BACKGROUND Reward processing deficits are a core feature of schizophrenia and are thought to underlie negative symptoms. Pre-clinical evidence suggests that opioid neurotransmission is linked to reward processing. However, the contribution of Mu Opioid Receptor (MOR) signalling to the reward processing abnormalities in schizophrenia is unknown. Here, we examined the association between MOR availability and the neural processes underlying reward anticipation in patients with schizophrenia using multimodal neuroimaging. METHOD 37 subjects (18 with Schizophrenia with moderate severity negative symptoms and 19 age and sex-matched healthy controls) underwent a functional MRI scan while performing the Monetary Incentive Delay (MID) task to measure the neural response to reward anticipation. Participants also had a [11C]-carfentanil PET scan to measure MOR availability. RESULTS Reward anticipation was associated with increased neural activation in a widespread network of brain regions including the striatum. Patients with schizophrenia had both significantly lower MOR availability in the striatum as well as striatal hypoactivation during reward anticipation. However, there was no association between MOR availability and striatal neural activity during reward anticipation in either patient or controls (Pearson's Correlation, controls df = 17, r = 0.321, p = 0.18, patients df = 16, r = 0.295, p = 0.24). There was no association between anticipation-related neural activation and negative symptoms (r = -0.120, p = 0.14) or anhedonia severity (social r = -0.365, p = 0.14 physical r = -0.120, p = 0.63). CONCLUSIONS Our data suggest reduced MOR availability in schizophrenia might not underlie striatal hypoactivation during reward anticipation in patients with established illness. Therefore, other mechanisms, such as dopamine dysfunction, warrant further investigation as treatment targets for this aspect of the disorder.
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Affiliation(s)
- Ekaterina Shatalina
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, London, UK; Psychiatric Imaging Group, Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, UK; Department of Psychosis, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, UK
| | - Abhishekh H Ashok
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, London, UK; Psychiatric Imaging Group, Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, UK; Department of Psychosis, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, UK; Department of Radiology, Addenbrooke's Hospital, Cambridge University Hospital NHS Foundation Trust, Cambridge, UK; Department of Radiology, University of Cambridge, Cambridge, UK
| | - Matthew B Wall
- Invicro, London, UK; Faculty of Medicine, Imperial College London, London, UK; Clinical Psychopharmacology Unit, University College London, London, UK
| | - Matthew M Nour
- Max Planck UCL Centre for Computational Psychiatry and Ageing Research, University College London, London, UK; Wellcome Centre for Human Neuroimaging (WCHN), University College London, London, UK
| | - Jim Myers
- Faculty of Medicine, Imperial College London, London, UK
| | - Tiago Reis Marques
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, London, UK; Psychiatric Imaging Group, Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, UK; Department of Psychosis, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, UK
| | - Eugenii A Rabiner
- Invicro, London, UK; Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, UK
| | - Oliver D Howes
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, London, UK; Psychiatric Imaging Group, Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, UK; Department of Psychosis, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, UK.
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7
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Jia Y, Xu L, Wang L, Yan K, Chen J, Xu P, Di B, Yan F, Hu C. A light-up fluorescence probe for wash-free analysis of Mu-opioid receptor and ligand-binding events. Anal Chim Acta 2023; 1261:341220. [PMID: 37147056 DOI: 10.1016/j.aca.2023.341220] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 04/01/2023] [Accepted: 04/13/2023] [Indexed: 05/07/2023]
Abstract
With the aggravated burden of opioid use disorder spreading worldwide, demands for new forms of opioid receptor agonist/antagonist constitute immense research interest. The Mu-opioid receptor (MOR) is currently in the spotlight on account of its general involvement in opioid-induced antinociception, tolerance and dependence. MOR binding assay, however, is often complicated by difficulty in MOR separation and purification, as well as the tedious procedure in standard biolayer interferometry and surface plasmon resonance measurements. To this end, we present TPE2N as a light-up fluorescent probe for MOR, which exhibits satisfactory performance in both live cells and lysates. TPE2N was elaborately designed based on the synergistic effect of twisted intramolecular charge-transfer and aggregation-induced emission by incorporating a tetraphenylethene unit to emit strong fluorescence in a restrained environment upon binding with MOR through the naloxone pharmacore. The developed assay enabled high-throughput screening of a compound library, and successfully identified three ligands as lead compounds for further development.
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Affiliation(s)
- Yan Jia
- China National Narcotics Control Commission-China Pharmaceutical University Joint Laboratory on Key Technologies of Narcotics Control, No. 24 Tongjiaxiang Road, Nanjing, 210009, China
| | - Lili Xu
- China National Narcotics Control Commission-China Pharmaceutical University Joint Laboratory on Key Technologies of Narcotics Control, No. 24 Tongjiaxiang Road, Nanjing, 210009, China
| | - Lancheng Wang
- China National Narcotics Control Commission-China Pharmaceutical University Joint Laboratory on Key Technologies of Narcotics Control, No. 24 Tongjiaxiang Road, Nanjing, 210009, China
| | - Kun Yan
- China National Narcotics Control Commission-China Pharmaceutical University Joint Laboratory on Key Technologies of Narcotics Control, No. 24 Tongjiaxiang Road, Nanjing, 210009, China
| | - Jieru Chen
- China National Narcotics Control Commission-China Pharmaceutical University Joint Laboratory on Key Technologies of Narcotics Control, No. 24 Tongjiaxiang Road, Nanjing, 210009, China
| | - Pengcheng Xu
- China National Narcotics Control Commission-China Pharmaceutical University Joint Laboratory on Key Technologies of Narcotics Control, No. 24 Tongjiaxiang Road, Nanjing, 210009, China
| | - Bin Di
- China National Narcotics Control Commission-China Pharmaceutical University Joint Laboratory on Key Technologies of Narcotics Control, No. 24 Tongjiaxiang Road, Nanjing, 210009, China.
| | - Fang Yan
- China National Narcotics Control Commission-China Pharmaceutical University Joint Laboratory on Key Technologies of Narcotics Control, No. 24 Tongjiaxiang Road, Nanjing, 210009, China.
| | - Chi Hu
- China National Narcotics Control Commission-China Pharmaceutical University Joint Laboratory on Key Technologies of Narcotics Control, No. 24 Tongjiaxiang Road, Nanjing, 210009, China.
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Zafar R, Siegel M, Harding R, Barba T, Agnorelli C, Suseelan S, Roseman L, Wall M, Nutt DJ, Erritzoe D. Psychedelic therapy in the treatment of addiction: the past, present and future. Front Psychiatry 2023; 14:1183740. [PMID: 37377473 PMCID: PMC10291338 DOI: 10.3389/fpsyt.2023.1183740] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 05/15/2023] [Indexed: 06/29/2023] Open
Abstract
Psychedelic therapy has witnessed a resurgence in interest in the last decade from the scientific and medical communities with evidence now building for its safety and efficacy in treating a range of psychiatric disorders including addiction. In this review we will chart the research investigating the role of these interventions in individuals with addiction beginning with an overview of the current socioeconomic impact of addiction, treatment options, and outcomes. We will start by examining historical studies from the first psychedelic research era of the mid-late 1900s, followed by an overview of the available real-world evidence gathered from naturalistic, observational, and survey-based studies. We will then cover modern-day clinical trials of psychedelic therapies in addiction from first-in-human to phase II clinical trials. Finally, we will provide an overview of the different translational human neuropsychopharmacology techniques, including functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), that can be applied to foster a mechanistic understanding of therapeutic mechanisms. A more granular understanding of the treatment effects of psychedelics will facilitate the optimisation of the psychedelic therapy drug development landscape, and ultimately improve patient outcomes.
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Affiliation(s)
- Rayyan Zafar
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
- Neuropsychopharmacology Unit, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Maxim Siegel
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
- Neuropsychopharmacology Unit, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Rebecca Harding
- Clinical Psychopharmacology Unit, University College London, London, United Kingdom
| | - Tommaso Barba
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
- Neuropsychopharmacology Unit, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Claudio Agnorelli
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
- Neuropsychopharmacology Unit, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Shayam Suseelan
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
- Neuropsychopharmacology Unit, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Leor Roseman
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
- Neuropsychopharmacology Unit, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Matthew Wall
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
- Neuropsychopharmacology Unit, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
- Invicro, London, United Kingdom
| | - David John Nutt
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
- Neuropsychopharmacology Unit, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - David Erritzoe
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
- Neuropsychopharmacology Unit, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
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9
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Hosseinzadeh Sahafi O, Sardari M, Alijanpour S, Rezayof A. Shared Mechanisms of GABAergic and Opioidergic Transmission Regulate Corticolimbic Reward Systems and Cognitive Aspects of Motivational Behaviors. Brain Sci 2023; 13:brainsci13050815. [PMID: 37239287 DOI: 10.3390/brainsci13050815] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 05/12/2023] [Accepted: 05/16/2023] [Indexed: 05/28/2023] Open
Abstract
The functional interplay between the corticolimbic GABAergic and opioidergic systems plays a crucial role in regulating the reward system and cognitive aspects of motivational behaviors leading to the development of addictive behaviors and disorders. This review provides a summary of the shared mechanisms of GABAergic and opioidergic transmission, which modulate the activity of dopaminergic neurons located in the ventral tegmental area (VTA), the central hub of the reward mechanisms. This review comprehensively covers the neuroanatomical and neurobiological aspects of corticolimbic inhibitory neurons that express opioid receptors, which act as modulators of corticolimbic GABAergic transmission. The presence of opioid and GABA receptors on the same neurons allows for the modulation of the activity of dopaminergic neurons in the ventral tegmental area, which plays a key role in the reward mechanisms of the brain. This colocalization of receptors and their immunochemical markers can provide a comprehensive understanding for clinicians and researchers, revealing the neuronal circuits that contribute to the reward system. Moreover, this review highlights the importance of GABAergic transmission-induced neuroplasticity under the modulation of opioid receptors. It discusses their interactive role in reinforcement learning, network oscillation, aversive behaviors, and local feedback or feedforward inhibitions in reward mechanisms. Understanding the shared mechanisms of these systems may lead to the development of new therapeutic approaches for addiction, reward-related disorders, and drug-induced cognitive impairment.
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Affiliation(s)
- Oveis Hosseinzadeh Sahafi
- Department of Animal Biology, School of Biology, College of Science, University of Tehran, Tehran 14155-6465, Iran
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Maryam Sardari
- Department of Animal Biology, School of Biology, College of Science, University of Tehran, Tehran 14155-6465, Iran
| | - Sakineh Alijanpour
- Department of Biology, Faculty of Science, Gonbad Kavous University, Gonbad Kavous 4971799151, Iran
| | - Ameneh Rezayof
- Department of Animal Biology, School of Biology, College of Science, University of Tehran, Tehran 14155-6465, Iran
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10
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Garcia Guerra S, Spadoni A, Mitchell J, Strigo IA. Pain-related opioidergic and dopaminergic neurotransmission: Dual meta-Analyses of PET radioligand studies. Brain Res 2023; 1805:148268. [PMID: 36754138 PMCID: PMC11018310 DOI: 10.1016/j.brainres.2023.148268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 01/13/2023] [Accepted: 01/30/2023] [Indexed: 02/08/2023]
Abstract
Molecular mechanisms of the interaction between opioidergic and dopaminergic processing during pain-related experiences in the human brain are still incompletely understood. This is partially due to the invasive nature of the available techniques to visualize and measure metabolic activity. Positron Emission Tomography (PET) radioligand studies using radioactive substances are still the only available modality to date that allows for the investigation of the molecular mechanisms in the human brain. The most commonly studied PET radiotracers are [11C]-carfentanil (CFN) and [11C]- or [18F]-diprenorphine (DPN), which bind to opioid receptors, and [11C]-raclopride (RAC) and [18F]-fallypride (FAL) tracers, which bind to dopamine receptors. The current meta-analysis examines pain-related studies that used aforementioned opioid and dopamine radioligands in an effort to consolidate the available data into the most likely activated regions. Our primary goal was to identify regions of shared opioid/dopamine neurotransmission during pain-related experiences using within-subject approach. Seed-based d Mapping (SDM) analysis of previously published voxel coordinate data showed that opioidergic activations were strongest in the bilateral caudate, thalamus, right putamen, cingulate gyrus, midbrain, inferior frontal gyrus, and left superior temporal gyrus. The dopaminergic studies showed that the bilateral caudate, thalamus, right putamen, cingulate gyrus, and left putamen had the highest activations. We were able to see a clear overlap between opioid and dopamine activations in a majority of the regions during pain-related experiences, though there were some unique areas of dopaminergic activation such as the left putamen. Regions unique to opioidergic activation included the midbrain, inferior frontal gyrus, and left superior temporal gyrus. Here we provide initial evidence for the functional overlap between opioidergic and dopaminergic processing during aversive states in humans.
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Affiliation(s)
- Sergio Garcia Guerra
- Research Service, San Francisco Veterans Affairs Health Care Center, 4150 Clement Street, San Francisco, CA 94121, USA; University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143, USA
| | - Andrea Spadoni
- Research Service, San Diego Veterans Affairs Health Care Center, USA; University of California San Diego, La Jolla, CA 92093, USA
| | - Jennifer Mitchell
- Research Service, San Francisco Veterans Affairs Health Care Center, 4150 Clement Street, San Francisco, CA 94121, USA; University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143, USA
| | - Irina A Strigo
- Research Service, San Francisco Veterans Affairs Health Care Center, 4150 Clement Street, San Francisco, CA 94121, USA; University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143, USA.
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11
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Berg M, Riehle M, Rief W, Lincoln T. Does partial blockade of dopamine D2 receptors with Amisulpride cause anhedonia? An experimental study in healthy volunteers. J Psychiatr Res 2023; 158:409-416. [PMID: 36680855 DOI: 10.1016/j.jpsychires.2023.01.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 12/22/2022] [Accepted: 01/09/2023] [Indexed: 01/12/2023]
Abstract
BACKGROUND Anhedonia is a frequent cause of functional impairment in psychosis. Although it is plausible that medication-induced D2 receptor blockade could diminish hedonic responding, there is little experimental research testing this hypothesis in humans. METHODS To inspect possible effects of partial D2 blockade on hedonic experiences, we administered 300 mg of Amisulpride or placebo to 85 participants in a randomized, double-blind, placebo-controlled trial. Participants were then subjected to an emotional evocation task utilizing standardized pictorial pleasant, neutral, and unpleasant stimuli. RESULTS We observed lower positivity ratings in the Amisulpride group compared to placebo across all stimulus categories (p = .026, f = 0.25) and no group differences in negativity or arousal ratings. The Amisulpride group also showed lower electrodermal responses across all stimulus categories compared to placebo (p = .017, f = 0.27). The electrodermal response was especially diminished for pleasant stimuli. CONCLUSION We interpret our findings as evidence that D2 blockade via Amisulpride can reduce at-the-moment hedonic responsivity in healthy volunteers. If these results can be confirmed in drug-naïve clinical samples, this would indicate that antipsychotic medication contributes to clinical anhedonia, probably via antagonistic effects at the dopamine D2 receptor.
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Affiliation(s)
- Max Berg
- Philipps-University of Marburg, Dept. of Psychology, Division of Clinical Psychology and Psychotherapy, Gutenbergstraße 18, D-35032, Marburg, Germany.
| | - Marcel Riehle
- Universität Hamburg, Dept. of Psychology, Clinical Psychology and Psychotherapy, Von-Melle-Park 5, D-20146, Hamburg, Germany
| | - Winfried Rief
- Philipps-University of Marburg, Dept. of Psychology, Division of Clinical Psychology and Psychotherapy, Gutenbergstraße 18, D-35032, Marburg, Germany
| | - Tania Lincoln
- Universität Hamburg, Dept. of Psychology, Clinical Psychology and Psychotherapy, Von-Melle-Park 5, D-20146, Hamburg, Germany
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12
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Sone D, Galovic M, Myers J, Leonhardt G, Rabiner I, Duncan JS, Koepp MJ, Foong J. Contribution of the μ-opioid receptor system to affective disorders in temporal lobe epilepsy: A bidirectional relationship? Epilepsia 2023; 64:420-429. [PMID: 36377838 PMCID: PMC10107876 DOI: 10.1111/epi.17463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 11/12/2022] [Accepted: 11/14/2022] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Affective disorders are frequent comorbidities of temporal lobe epilepsy (TLE). The endogenous opioid system has been implicated in both epilepsy and affective disorders, and may play a significant role in their bidirectional relationship. In this cross-sectional study, we investigated the association between μ-opioid receptor binding and affective disorders in patients with TLE. METHODS Nine patients with TLE and depression/anxiety underwent 11 C-carfentanil positron emission tomography (CFN PET) and neuropsychiatric assessment, including the Hospital Anxiety and Depression Scale and the Positive and Negative Affect Schedule. The normalized CFN PET scans were compared with those of 26 age-matched healthy controls. Correlation analyses with affective symptoms were performed by region of interest-based analysis focusing on the limbic circuit and orbitofrontal cortex. RESULTS We observed widely reduced CFN binding potential (BP) in bilateral frontal lobes and striata in patients with TLE compared to healthy controls. In the TLE group, more severe anxiety and negative affect were associated with decreased CFN BP in the posterior cingulate gyrus. SIGNIFICANCE In patients with TLE, interictally reduced binding in the opioid system was associated with higher levels of anxiety and negative affect. We speculate that seizure-related agonist-driven desensitization and downregulation of opioid receptors could be a potential underlying pathomechanism.
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Affiliation(s)
- Daichi Sone
- Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, UK
- Department of Psychiatry, Jikei University School of Medicine, Tokyo, Japan
| | - Marian Galovic
- Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, UK
- Department of Neurology, Clinical Neuroscience Center, University Hospital Zurich, Zurich, Switzerland
| | - Jim Myers
- Faculty of Medicine, Imperial College London, London, UK
| | - Georg Leonhardt
- Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, UK
- Department of Neurosurgery, Carl Gustav Carus University Hospitals, Dresden, Germany
| | | | - John S Duncan
- Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, UK
| | - Matthias J Koepp
- Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, UK
| | - Jacqueline Foong
- Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, UK
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13
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Rysztak LG, Jutkiewicz EM. The role of enkephalinergic systems in substance use disorders. Front Syst Neurosci 2022; 16:932546. [PMID: 35993087 PMCID: PMC9391026 DOI: 10.3389/fnsys.2022.932546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 06/29/2022] [Indexed: 12/13/2022] Open
Abstract
Enkephalin, an endogenous opioid peptide, is highly expressed in the reward pathway and may modulate neurotransmission to regulate reward-related behaviors, such as drug-taking and drug-seeking behaviors. Drugs of abuse also directly increase enkephalin in this pathway, yet it is unknown whether or not changes in the enkephalinergic system after drug administration mediate any specific behaviors. The use of animal models of substance use disorders (SUDs) concurrently with pharmacological, genetic, and molecular tools has allowed researchers to directly investigate the role of enkephalin in promoting these behaviors. In this review, we explore neurochemical mechanisms by which enkephalin levels and enkephalin-mediated signaling are altered by drug administration and interrogate the contribution of enkephalin systems to SUDs. Studies manipulating the receptors that enkephalin targets (e.g., mu and delta opioid receptors mainly) implicate the endogenous opioid peptide in drug-induced neuroadaptations and reward-related behaviors; however, further studies will need to confirm the role of enkephalin directly. Overall, these findings suggest that the enkephalinergic system is involved in multiple aspects of SUDs, such as the primary reinforcing properties of drugs, conditioned reinforcing effects, and sensitization. The idea of dopaminergic-opioidergic interactions in these behaviors remains relatively novel and warrants further research. Continuing work to elucidate the role of enkephalin in mediating neurotransmission in reward circuitry driving behaviors related to SUDs remains crucial.
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Affiliation(s)
- Lauren G. Rysztak
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, United States
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, United States
| | - Emily M. Jutkiewicz
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, United States
- *Correspondence: Emily M. Jutkiewicz,
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14
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Rabiner EA, Uz T, Mansur A, Brown T, Chen G, Wu J, Atienza J, Schwarz AJ, Yin W, Lewis Y, Searle GE, Dennison JMTJ, Passchier J, Gunn RN, Tauscher J. Endogenous dopamine release in the human brain as a pharmacodynamic biomarker: evaluation of the new GPR139 agonist TAK-041 with [ 11C]PHNO PET. Neuropsychopharmacology 2022; 47:1405-1412. [PMID: 34675381 PMCID: PMC9117280 DOI: 10.1038/s41386-021-01204-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 09/03/2021] [Accepted: 09/29/2021] [Indexed: 01/01/2023]
Abstract
The use of positron emission tomography (PET) in early-phase development of novel drugs targeting the central nervous system, is well established for the evaluation of brain penetration and target engagement. However, when novel targets are involved a suitable PET ligand is not always available. We demonstrate an alternative approach that evaluates the attenuation of amphetamine-induced synaptic dopamine release by a novel agonist of the orphan G-protein-coupled receptor GPR139 (TAK-041). GPR139 agonism is a novel candidate mechanism for the treatment of schizophrenia and other disorders associated with social and cognitive dysfunction. Ten healthy volunteers underwent [11C]PHNO PET at baseline, and twice after receiving an oral dose of d-amphetamine (0.5 mg/kg). One of the post-d-amphetamine scans for each subject was preceded by a single oral dose of TAK-041 (20 mg in five; 40 mg in the other five participants). D-amphetamine induced a significant decrease in [11C]PHNO binding potential relative to the non-displaceable component (BPND) in all regions examined (16-28%), consistent with increased synaptic dopamine release. Pre-treatment with TAK-041 significantly attenuated the d-amphetamine-induced reduction in BPND in the a priori defined regions (putamen and ventral striatum: 26% and 18%, respectively). The reduction in BPND was generally higher after the 40 mg than the 20 mg TAK-041 dose, with the difference between doses reaching statistical significance in the putamen. Our findings suggest that TAK-041 enters the human brain and interacts with GPR139 to affect endogenous dopamine release. [11C]PHNO PET is a practical method to detect the effects of novel drugs on the brain dopaminergic system in healthy volunteers, in the early stages of drug development.
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Affiliation(s)
- Eugenii A. Rabiner
- grid.498414.40000 0004 0548 3187Invicro, London, UK ,grid.13097.3c0000 0001 2322 6764Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
| | - Tolga Uz
- grid.419849.90000 0004 0447 7762Takeda Pharmaceuticals Ltd, Cambridge, MA USA
| | - Ayla Mansur
- grid.498414.40000 0004 0548 3187Invicro, London, UK
| | - Terry Brown
- grid.419849.90000 0004 0447 7762Takeda Pharmaceuticals Ltd, Cambridge, MA USA
| | - Grace Chen
- grid.419849.90000 0004 0447 7762Takeda Pharmaceuticals Ltd, Cambridge, MA USA
| | - Jingtao Wu
- grid.419849.90000 0004 0447 7762Takeda Pharmaceuticals Ltd, Cambridge, MA USA
| | - Joy Atienza
- grid.419849.90000 0004 0447 7762Takeda Pharmaceuticals Ltd, Cambridge, MA USA
| | - Adam J. Schwarz
- grid.419849.90000 0004 0447 7762Takeda Pharmaceuticals Ltd, Cambridge, MA USA
| | - Wei Yin
- grid.419849.90000 0004 0447 7762Takeda Pharmaceuticals Ltd, Cambridge, MA USA
| | - Yvonne Lewis
- grid.498414.40000 0004 0548 3187Invicro, London, UK
| | | | | | | | | | - Johannes Tauscher
- grid.419849.90000 0004 0447 7762Takeda Pharmaceuticals Ltd, Cambridge, MA USA
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15
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Jones P. Mindfulness and Nondual Well-Being – What is the Evidence that We Can Stay Happy? REVIEW OF GENERAL PSYCHOLOGY 2022. [DOI: 10.1177/10892680221093013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Research into subjective well-being (SWB) focuses on conducive life conditions, healthy cognitive-affective processes and adaptive behaviours, however, in this model, well-being fluctuates based on changing mental and physical phenomena. This inquiry explores the possibility that we can have a nondual experience of well-being that is unaffected by such movements and investigates if the literature supports this. The assertion in traditional mindfulness that the sense of self is constructed and responsible for such fluctuations is explored, along with what evidence there is that mindfulness practices deliver relevant cognitive and behavioural correlates associated with such a way of being. Proposed preconditions include (a) nondual awareness or the perception of no-self; (b) increased positive affect, decreased negative affect, and increased self-lessness; (c) increased capacity to maintain (or protect) well-being including heightened emotional self-regulation and resilience to aversive stimuli. Research findings provide some evidence that the sense of self can be both constructed and deconstructed, and that mindfulness training may target psychological dimensions that could contribute to an experience of well-being that transcends the impact of life conditions. Recommendations are made for a collaborative relationship between SWB research and mindfulness to expand the inquiry into possible causes and conditions of ‘nondual well-being’.
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Affiliation(s)
- Patrick Jones
- College of Science, Health, Engineering and Education (SHEE), Murdoch University, Perth, WA, Australia
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16
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Herlinger K, Lingford-Hughes A. Opioid use disorder and the brain: a clinical perspective. Addiction 2022; 117:495-505. [PMID: 34228373 DOI: 10.1111/add.15636] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/16/2021] [Accepted: 06/18/2021] [Indexed: 02/06/2023]
Abstract
Opioid use disorder (OUD) has gained increasing publicity and interest during recent years, with many countries describing problems of epidemic proportions with regard to opioid use and deaths related to opioids. While opioids are not themselves acutely neurotoxic, the chronic relapsing and remitting nature of this disorder means that individuals are often exposed to exogenous opioids for lengthy periods of time (either illicit or prescribed as treatment). We are increasingly characterizing the effect of such long-term opioid exposure on the brain. This narrative review aims to summarize the literature regarding OUD and the brain from a clinical perspective. Alterations of brain structure and function are discussed, as well as neurological and psychiatric disorders in OUD. Finally, we review current and new directions for assessment and treatment.
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Affiliation(s)
- Katherine Herlinger
- MRC Addiction Research Clinical Training Programme, Imperial College London, London, UK
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17
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Loganathan K. Value-based cognition and drug dependency. Addict Behav 2021; 123:107070. [PMID: 34359016 DOI: 10.1016/j.addbeh.2021.107070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 07/03/2021] [Accepted: 07/26/2021] [Indexed: 10/20/2022]
Abstract
Value-based decision-making is thought to play an important role in drug dependency. Achieving elevated levels of euphoria or ameliorating dysphoria/pain may motivate goal-directed drug consumption in both drug-naïve and long-time users. In other words, drugs become viewed as the preferred means of attaining a desired internal state. The bias towards choosing drugs may affect one's cognition. Observed biases in learning, attention and memory systems within the brain gradually focus one's cognitive functions towards drugs and related cues to the exclusion of other stimuli. In this narrative review, the effects of drug use on learning, attention and memory are discussed with a particular focus on changes across brain-wide functional networks and the subsequent impact on behaviour. These cognitive changes are then incorporated into the cycle of addiction, an established model outlining the transition from casual drug use to chronic dependency. If drug use results in the elevated salience of drugs and their cues, the studies highlighted in this review strongly suggest that this salience biases cognitive systems towards the motivated pursuit of addictive drugs. This bias is observed throughout the cycle of addiction, possibly contributing to the persistent hold that addictive drugs have over the dependent. Taken together, the excessive valuation of drugs as the preferred means of achieving a desired internal state affects more than just decision-making, but also learning, attentional and mnemonic systems. This eventually narrows the focus of one's thoughts towards the pursuit and consumption of addictive drugs.
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18
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Ashok AH, Myers J, Frost G, Turton S, Gunn RN, Passchier J, Colasanti A, Marques TR, Nutt D, Lingford-Hughes A, Howes OD, Rabiner EA. Acute acetate administration increases endogenous opioid levels in the human brain: A [ 11C]carfentanil molecular imaging study. J Psychopharmacol 2021; 35:606-610. [PMID: 33406950 PMCID: PMC8155733 DOI: 10.1177/0269881120965912] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
INTRODUCTION A recent study has shown that acetate administration leads to a fourfold increase in the transcription of proopiomelanocortin (POMC) mRNA in the hypothalamus. POMC is cleaved to peptides, including β-endorphin, an endogenous opioid (EO) agonist that binds preferentially to the µ-opioid receptor (MOR). We hypothesised that an acetate challenge would increase the levels of EO in the human brain. We have previously demonstrated that increased EO release in the human brain can be detected using positron emission tomography (PET) with the selective MOR radioligand [11C]carfentanil. We used this approach to evaluate the effects of an acute acetate challenge on EO levels in the brain of healthy human volunteers. METHODS Seven volunteers each completed a baseline [11C]carfentanil PET scan followed by an administration of sodium acetate before a second [11C]carfentanil PET scan. Dynamic PET data were acquired over 90 minutes, and corrected for attenuation, scatter and subject motion. Regional [11C] carfentanil BPND values were then calculated using the simplified reference tissue model (with the occipital grey matter as the reference region). Change in regional EO concentration was evaluated as the change in [11C]carfentanil BPND following acetate administration. RESULTS Following sodium acetate administration, 2.5-6.5% reductions in [11C]carfentanil regional BPND were seen, with statistical significance reached in the cerebellum, temporal lobe, orbitofrontal cortex, striatum and thalamus. CONCLUSIONS We have demonstrated that an acute acetate challenge has the potential to increase EO release in the human brain, providing a plausible mechanism of the central effects of acetate on appetite in humans.
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Affiliation(s)
- Abhishekh H Ashok
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences (LMS), Imperial College London, London, UK.,Psychiatric Imaging Group, Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, UK.,Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.,Department of Radiology, University of Cambridge, Cambridge, UK.,Department of Radiology, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | | | | | - Samuel Turton
- Imperial College London, UK.,Institute of Psychiatry, Psychology and Neurosciences, King's College London, London, UK
| | - Roger N Gunn
- Imperial College London, UK.,Invicro, London, UK
| | | | - Alessandro Colasanti
- Department of Neuroscience, Brighton and Sussex Medical School, University of Sussex, Brighton, UK
| | - Tiago Reis Marques
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences (LMS), Imperial College London, London, UK.,Psychiatric Imaging Group, Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, UK.,Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | | | | | - Oliver D Howes
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences (LMS), Imperial College London, London, UK.,Psychiatric Imaging Group, Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, UK.,Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Eugenii A Rabiner
- Institute of Psychiatry, Psychology and Neurosciences, King's College London, London, UK.,Invicro, London, UK
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19
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Mesolimbic opioid-dopamine interaction is disrupted in obesity but recovered by weight loss following bariatric surgery. Transl Psychiatry 2021; 11:259. [PMID: 33934103 PMCID: PMC8088437 DOI: 10.1038/s41398-021-01370-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 03/18/2021] [Accepted: 04/06/2021] [Indexed: 12/02/2022] Open
Abstract
Obesity is a growing burden to health and the economy worldwide. Obesity is associated with central µ-opioid receptor (MOR) downregulation and disruption of the interaction between MOR and dopamine D2 receptor (D2R) system in the ventral striatum. Weight loss recovers MOR function, but it remains unknown whether it also recovers aberrant opioid-dopamine interaction. Here we addressed this issue by studying 20 healthy non-obese and 25 morbidly obese women (mean BMI 41) eligible for bariatric surgery. Brain MOR and D2R availability were measured using positron emission tomography (PET) with [11C]carfentanil and [11C]raclopride, respectively. Either Roux-en-Y gastric bypass or sleeve gastrectomy was performed on obese subjects according to standard clinical treatment. 21 obese subjects participated in the postoperative PET scanning six months after bariatric surgery. In the control subjects, MOR and D2R availabilities were associated in the ventral striatum (r = .62) and dorsal caudate (r = .61). Preoperatively, the obese subjects had disrupted association in the ventral striatum (r = .12) but the unaltered association in dorsal caudate (r = .43). The association between MOR and D2R availabilities in the ventral striatum was recovered (r = .62) among obese subjects following the surgery-induced weight loss. Bariatric surgery and concomitant weight loss recover the interaction between MOR and D2R in the ventral striatum in the morbidly obese. Consequently, the dysfunctional opioid-dopamine interaction in the ventral striatum is likely associated with an obese phenotype and may mediate excessive energy uptake. Striatal opioid-dopamine interaction provides a feasible target for pharmacological and behavioral interventions for treating obesity.
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20
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Herlinger K, Lingford-Hughes A. Addressing unmet needs in opiate dependence: supporting detoxification and advances in relapse prevention. BJPSYCH ADVANCES 2021. [DOI: 10.1192/bja.2020.98] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
SUMMARY
Despite record-breaking numbers of opiate related deaths in the UK in 2019, pharmacological management of opiate dependence has evolved little since the advent of methadone in 1965. Along with harm minimisation and psychosocial interventions, the mainstay of pharmacological treatment remains opioid substitution therapy (OST) using methadone or buprenorphine, with many patients receiving OST for many years. Even with these treatments, opiate users continue to face mortality risks 12 times higher than the general population, and emerging evidence suggests that individuals who remain on long-term OST present with a range of physical and cognitive impairments. Therefore, with a growing ageing opiate dependent population who would benefit from detoxification from OST, this article provides an overview of the current state of opiate dependence in clinical practice, explores the reasons why availability and acceptability of detoxification pathways are declining, and discusses emerging pharmacological therapies that could provide benefit in relapse prevention.
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21
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Using pharmacological manipulations to study the role of dopamine in human reward functioning: A review of studies in healthy adults. Neurosci Biobehav Rev 2020; 120:123-158. [PMID: 33202256 DOI: 10.1016/j.neubiorev.2020.11.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 10/30/2020] [Accepted: 11/01/2020] [Indexed: 01/08/2023]
Abstract
Dopamine (DA) plays a key role in reward processing and is implicated in psychological disorders such as depression, substance use, and schizophrenia. The role of DA in reward processing is an area of highly active research. One approach to this question is drug challenge studies with drugs known to alter DA function. These studies provide good experimental control and can be performed in parallel in laboratory animals and humans. This review aimed to summarize results of studies using pharmacological manipulations of DA in healthy adults. 'Reward' is a complex process, so we separated 'phases' of reward, including anticipation, evaluation of cost and benefits of upcoming reward, execution of actions to obtain reward, pleasure in response to receiving a reward, and reward learning. Results indicated that i) DAergic drugs have different effects on different phases of reward; ii) the relationship between DA and reward functioning appears unlikely to be linear; iii) our ability to detect the effects of DAergic drugs varies depending on whether subjective, behavioral, imaging measures are used.
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22
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Zhao Y, Rütgen M, Zhang L, Lamm C. Pharmacological fMRI provides evidence for opioidergic modulation of discrimination of facial pain expressions. Psychophysiology 2020; 58:e13717. [PMID: 33140886 PMCID: PMC7816233 DOI: 10.1111/psyp.13717] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 09/03/2020] [Accepted: 10/09/2020] [Indexed: 12/21/2022]
Abstract
The endogenous opioid system is strongly involved in the modulation of pain. However, the potential role of this system in perceiving painful facial expressions from others has not been sufficiently explored as of yet. To elucidate the contribution of the opioid system to the perception of painful facial expressions, we conducted a double‐blind, within‐subjects pharmacological functional magnetic resonance imaging (fMRI) study, in which 42 participants engaged in an emotion discrimination task (pain vs. disgust expressions) in two experimental sessions, receiving either the opioid receptor antagonist naltrexone or an inert substance (placebo). On the behavioral level, participants less frequently judged an expression as pain under naltrexone as compared to placebo. On the neural level, parametric modulation of activation in the (putative) right fusiform face area (FFA), which was correlated with increased pain intensity, was higher under naltrexone than placebo. Regression analyses revealed that brain activity in the right FFA significantly predicted behavioral performance in disambiguating pain from disgust, both under naltrexone and placebo. These findings suggest that reducing opioid system activity decreased participants' sensitivity for facial expressions of pain, and that this was linked to possibly compensatory engagement of processes related to visual perception, rather than to higher level affective processes, and pain regulation. The behavioral and neural findings of this psychopharmacological fMRI study shed light on a causal role of the opioid system in the discrimination of painful facial expressions, paving the way for further exploration of clinical implications in the domains of pain diagnosis and treatment, on the one hand, and future research on the relationship between basic socio‐perceptual processing and empathy, on the other.
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Affiliation(s)
- Yili Zhao
- Social, Cognitive and Affective Neuroscience Unit, Department of Cognition, Emotion, and Methods in Psychology, Faculty of Psychology, University of Vienna, Vienna, Austria
| | - Markus Rütgen
- Social, Cognitive and Affective Neuroscience Unit, Department of Cognition, Emotion, and Methods in Psychology, Faculty of Psychology, University of Vienna, Vienna, Austria.,Vienna Cognitive Science Hub, University of Vienna, Vienna, Austria
| | - Lei Zhang
- Social, Cognitive and Affective Neuroscience Unit, Department of Cognition, Emotion, and Methods in Psychology, Faculty of Psychology, University of Vienna, Vienna, Austria.,Neuropsychopharmacology and Biopsychology Unit, Department of Cognition, Emotion, and Methods in Psychology, Faculty of Psychology, University of Vienna, Vienna, Austria
| | - Claus Lamm
- Social, Cognitive and Affective Neuroscience Unit, Department of Cognition, Emotion, and Methods in Psychology, Faculty of Psychology, University of Vienna, Vienna, Austria.,Vienna Cognitive Science Hub, University of Vienna, Vienna, Austria.,Neuropsychopharmacology and Biopsychology Unit, Department of Cognition, Emotion, and Methods in Psychology, Faculty of Psychology, University of Vienna, Vienna, Austria
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23
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Hayes A, Herlinger K, Paterson L, Lingford-Hughes A. The neurobiology of substance use and addiction: evidence from neuroimaging and relevance to treatment. BJPSYCH ADVANCES 2020. [DOI: 10.1192/bja.2020.68] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
SUMMARYAddiction is a global health problem with a chronic relapsing nature for which there are few treatment options. In the past few decades, neuroimaging has allowed us to better understand the neurobiology of addiction. Functional neuroimaging paradigms have been developed to probe the neural circuits underlying addiction, including reward, inhibitory control, stress, emotional processing and learning/memory networks. Functional neuroimaging has also been used to provide biological support for the benefits of psychosocial and pharmacological interventions, although evidence remains limited and often inconclusive in this area, which may contribute to the variability in treatment efficacy. In this article, we discuss the changing definitions and clinical criteria that describe and classify addictive disorders. Using examples from functional neuroimaging studies we summarise the neurobiological mechanisms that underpin drug use, dependence, tolerance, withdrawal and relapse. We discuss the links between functional neuroimaging and treatment, outline clinical management in the UK and give an overview of future directions in research and addiction services.
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24
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Turton S, Myers JF, Mick I, Colasanti A, Venkataraman A, Durant C, Waldman A, Brailsford A, Parkin MC, Dawe G, Rabiner EA, Gunn RN, Lightman SL, Nutt DJ, Lingford-Hughes A. Blunted endogenous opioid release following an oral dexamphetamine challenge in abstinent alcohol-dependent individuals. Mol Psychiatry 2020; 25:1749-1758. [PMID: 29942043 PMCID: PMC6169731 DOI: 10.1038/s41380-018-0107-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 05/09/2018] [Accepted: 05/14/2018] [Indexed: 01/12/2023]
Abstract
Addiction has been proposed as a 'reward deficient' state, which is compensated for with substance use. There is growing evidence of dysregulation in the opioid system, which plays a key role in reward, underpinning addiction. Low levels of endogenous opioids are implicated in vulnerability for developing alcohol dependence (AD) and high mu-opioid receptor (MOR) availability in early abstinence is associated with greater craving. This high MOR availability is proposed to be the target of opioid antagonist medication to prevent relapse. However, changes in endogenous opioid tone in AD are poorly characterised and are important to understand as opioid antagonists do not help everyone with AD. We used [11C]carfentanil, a selective MOR agonist positron emission tomography (PET) radioligand, to investigate endogenous opioid tone in AD for the first time. We recruited 13 abstinent male AD and 15 control participants who underwent two [11C]carfentanil PET scans, one before and one 3 h following a 0.5 mg/kg oral dose of dexamphetamine to measure baseline MOR availability and endogenous opioid release. We found significantly blunted dexamphetamine-induced opioid release in 5 out of 10 regions-of-interest including insula, frontal lobe and putamen in AD compared with controls, but no significantly higher MOR availability AD participants compared with HC in any region. This study is comparable to our previous results of blunted dexamphetamine-induced opioid release in gambling disorder, suggesting that this dysregulation in opioid tone is common to both behavioural and substance addictions.
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Affiliation(s)
- Samuel Turton
- Neuropsychopharmacology Unit, Centre for Psychiatry, Imperial College London, London, UK
| | - James Fm Myers
- Neuropsychopharmacology Unit, Centre for Psychiatry, Imperial College London, London, UK
| | - Inge Mick
- Neuropsychopharmacology Unit, Centre for Psychiatry, Imperial College London, London, UK
- Institute for Clinical Teratology and Drug Risk Assessment in Pregnancy, Charité Universitätsmedizin, Berlin, Germany
| | - Alessandro Colasanti
- Department of Neuroscience, Brighton and Sussex Medical School, University of Sussex, Brighton, UK
- Centre for Affective Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Ashwin Venkataraman
- Neuropsychopharmacology Unit, Centre for Psychiatry, Imperial College London, London, UK
| | - Claire Durant
- Neuropsychopharmacology Unit, Centre for Psychiatry, Imperial College London, London, UK
| | - Adam Waldman
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Alan Brailsford
- Analytical and Environmental Sciences, King's College London, London, UK
| | - Mark C Parkin
- Analytical and Environmental Sciences, King's College London, London, UK
| | - Gemma Dawe
- Department of Neuroradiology, Imperial College Healthcare NHS Trust, London, UK
| | - Eugenii A Rabiner
- Imanova Limited, London, UK
- Centre for Neuroimaging Sciences, King's College London, London, UK
| | - Roger N Gunn
- Imanova Limited, London, UK
- Centre for Restorative Neuroscience, Division of Brain Sciences, Imperial College London, London, UK
| | - Stafford L Lightman
- Henry Wellcome Laboratories for Integrative Neuroscience & Endocrinology, University of Bristol, Bristol, UK
| | - David J Nutt
- Neuropsychopharmacology Unit, Centre for Psychiatry, Imperial College London, London, UK
| | - Anne Lingford-Hughes
- Neuropsychopharmacology Unit, Centre for Psychiatry, Imperial College London, London, UK.
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25
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Serotonin release measured in the human brain: a PET study with [ 11C]CIMBI-36 and d-amphetamine challenge. Neuropsychopharmacology 2020; 45:804-810. [PMID: 31715617 PMCID: PMC7075951 DOI: 10.1038/s41386-019-0567-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 09/25/2019] [Accepted: 10/17/2019] [Indexed: 12/25/2022]
Abstract
Positron emission tomography (PET) enables non-invasive estimation of neurotransmitter fluctuations in the living human brain. While these methods have been applied to dopamine and some other transmitters, estimation of 5-hydroxytryptamine (5-HT; Serotonin) release has proved to be challenging. Here we demonstrate the utility of the novel 5-HT2A receptor agonist radioligand, [11C]CIMBI-36, and a d-amphetamine challenge to evaluate synaptic 5-HT changes in the living human brain. Seventeen healthy male volunteers received [11C]CIMBI-36 PET scans before and 3 h after an oral dose of d-amphetamine (0.5 mg/kg). Dynamic PET data were acquired over 90 min, and the total volume of distribution (VT) in the frontal cortex and the cerebellum derived from a kinetic analysis using MA1. The frontal cortex binding potential (BPNDfrontal) was calculated as (VTfrontal/VTcerebellum) - 1. ∆BPNDfrontal = 1 - (BPNDfrontal post-dose/BPNDfrontal baseline) was used as an index of 5-HT release. Statistical inference was tested by means of a paired Students t-test evaluating a reduction in post-amphetamine [11C]CIMBI-36 BPNDfrontal. Following d-amphetamine administration, [11C]CIMBI-36 BPNDfrontal was reduced by 14 ± 13% (p = 0.002). Similar effects were observed in other cortical regions examined in an exploratory analysis. [11C]CIMBI-36 binding is sensitive to synaptic serotonin release in the human brain, and when combined with a d-amphetamine challenge, the evaluation of the human brain serotonin system in neuropsychiatric disorders, such as major depression and Parkinson's disease is enabled.
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26
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McCluskey SP, Plisson C, Rabiner EA, Howes O. Advances in CNS PET: the state-of-the-art for new imaging targets for pathophysiology and drug development. Eur J Nucl Med Mol Imaging 2020; 47:451-489. [PMID: 31541283 PMCID: PMC6974496 DOI: 10.1007/s00259-019-04488-0] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 08/15/2019] [Indexed: 02/07/2023]
Abstract
PURPOSE A limit on developing new treatments for a number of central nervous system (CNS) disorders has been the inadequate understanding of the in vivo pathophysiology underlying neurological and psychiatric disorders and the lack of in vivo tools to determine brain penetrance, target engagement, and relevant molecular activity of novel drugs. Molecular neuroimaging provides the tools to address this. This article aims to provide a state-of-the-art review of new PET tracers for CNS targets, focusing on developments in the last 5 years for targets recently available for in-human imaging. METHODS We provide an overview of the criteria used to evaluate PET tracers. We then used the National Institute of Mental Health Research Priorities list to identify the key CNS targets. We conducted a PubMed search (search period 1st of January 2013 to 31st of December 2018), which yielded 40 new PET tracers across 16 CNS targets which met our selectivity criteria. For each tracer, we summarised the evidence of its properties and potential for use in studies of CNS pathophysiology and drug evaluation, including its target selectivity and affinity, inter and intra-subject variability, and pharmacokinetic parameters. We also consider its potential limitations and missing characterisation data, but not specific applications in drug development. Where multiple tracers were present for a target, we provide a comparison of their properties. RESULTS AND CONCLUSIONS Our review shows that multiple new tracers have been developed for proteinopathy targets, particularly tau, as well as the purinoceptor P2X7, phosphodiesterase enzyme PDE10A, and synaptic vesicle glycoprotein 2A (SV2A), amongst others. Some of the most promising of these include 18F-MK-6240 for tau imaging, 11C-UCB-J for imaging SV2A, 11C-CURB and 11C-MK-3168 for characterisation of fatty acid amide hydrolase, 18F-FIMX for metabotropic glutamate receptor 1, and 18F-MNI-444 for imaging adenosine 2A. Our review also identifies recurrent issues within the field. Many of the tracers discussed lack in vivo blocking data, reducing confidence in selectivity. Additionally, late-stage identification of substantial off-target sites for multiple tracers highlights incomplete pre-clinical characterisation prior to translation, as well as human disease state studies carried out without confirmation of test-retest reproducibility.
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Affiliation(s)
- Stuart P McCluskey
- Invicro LLC, A Konica Minolta Company, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK.
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Hospital, London, UK.
| | - Christophe Plisson
- Invicro LLC, A Konica Minolta Company, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Eugenii A Rabiner
- Invicro LLC, A Konica Minolta Company, Burlington Danes Building, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Oliver Howes
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Hospital, London, UK
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27
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Scarna H. Genesis of the Heroin-Induced Addictive Process: Articulation Between Psychodynamic and Neurobiological Theories. Front Psychiatry 2020; 11:524764. [PMID: 33362589 PMCID: PMC7755881 DOI: 10.3389/fpsyt.2020.524764] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 11/18/2020] [Indexed: 11/24/2022] Open
Abstract
Psychotherapeutic consultations of drug addict's patients in a Care, Support and Prevention Center in Addictology led us to propose several hypotheses on the genesis of addiction and its articulation with currently available neurobiological data. This care center dispenses both pharmacological maintenance medications for heroin dependence, such as methadone or buprenorphine, and psychological support. Our first hypothesis posits that the addictive process is driven by the narcissistic vulnerability of these patients, its neurobiological foundations being mainly mediated by the activation of endogenous opioid systems. Drug use/abuse could be a way to make arise the "True Self," therefore overcoming the defensive system's set up to protect oneself from early traumas. The neurobiological impact of traumas is also developed and articulated with psychodynamic concepts, particularly those of Winnicott. Additionally, functions of addiction such as defensive, anti-depressant roles and emotional regulation are discussed in relationship with their currently known neuroscientific bases. Although the experience in the psychodynamic clinic is at a level of complexity much higher than what is currently accessible to the neurosciences, most of the research in this domain stays in line with our psychological understanding of the addictive process. Finally, we outline some critically sensitive points regarding the therapeutic support.
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Affiliation(s)
- Hélène Scarna
- Centre de Recherche en Psychopathologie et Psychologie Clinique, Université Lumière Lyon 2, Bron, France.,Laboratoire de Psychologie EA 3188, Université de Bourgogne Franche-Comté, Besançon, France.,Univ Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, Bron, France.,Centre de Soin, d'Accompagnement et de Prévention en Addictologie, Hôpital de la Croix-Rousse, Lyon, France
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28
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A Survey of Molecular Imaging of Opioid Receptors. Molecules 2019; 24:molecules24224190. [PMID: 31752279 PMCID: PMC6891617 DOI: 10.3390/molecules24224190] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 11/11/2019] [Accepted: 11/13/2019] [Indexed: 01/09/2023] Open
Abstract
The discovery of endogenous peptide ligands for morphine binding sites occurred in parallel with the identification of three subclasses of opioid receptor (OR), traditionally designated as μ, δ, and κ, along with the more recently defined opioid-receptor-like (ORL1) receptor. Early efforts in opioid receptor radiochemistry focused on the structure of the prototype agonist ligand, morphine, although N-[methyl-11C]morphine, -codeine and -heroin did not show significant binding in vivo. [11C]Diprenorphine ([11C]DPN), an orvinol type, non-selective OR antagonist ligand, was among the first successful PET tracers for molecular brain imaging, but has been largely supplanted in research studies by the μ-preferring agonist [11C]carfentanil ([11C]Caf). These two tracers have the property of being displaceable by endogenous opioid peptides in living brain, thus potentially serving in a competition-binding model. Indeed, many clinical PET studies with [11C]DPN or [11C]Caf affirm the release of endogenous opioids in response to painful stimuli. Numerous other PET studies implicate μ-OR signaling in aspects of human personality and vulnerability to drug dependence, but there have been very few clinical PET studies of μORs in neurological disorders. Tracers based on naltrindole, a non-peptide antagonist of the δ-preferring endogenous opioid enkephalin, have been used in PET studies of δORs, and [11C]GR103545 is validated for studies of κORs. Structures such as [11C]NOP-1A show selective binding at ORL-1 receptors in living brain. However, there is scant documentation of δ-, κ-, or ORL1 receptors in healthy human brain or in neurological and psychiatric disorders; here, clinical PET research must catch up with recent progress in radiopharmaceutical chemistry.
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29
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Winterdahl M, Noer O, Orlowski D, Schacht AC, Jakobsen S, Alstrup AKO, Gjedde A, Landau AM. Sucrose intake lowers μ-opioid and dopamine D2/3 receptor availability in porcine brain. Sci Rep 2019; 9:16918. [PMID: 31729425 PMCID: PMC6858372 DOI: 10.1038/s41598-019-53430-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 10/31/2019] [Indexed: 12/26/2022] Open
Abstract
Excessive sucrose consumption elicits addiction-like craving that may underpin the obesity epidemic. Opioids and dopamine mediate the rewarding effects of drugs of abuse, and of natural rewards from stimuli such as palatable food. We investigated the effects of sucrose using PET imaging with [11C]carfentanil (μ-opioid receptor agonist) and [11C]raclopride (dopamine D2/3 receptor antagonist) in seven female anesthetized Göttingen minipigs. We then gave minipigs access to sucrose solution for one hour on 12 consecutive days and performed imaging again 24 hours after the final sucrose access. In a smaller sample of five minipigs, we performed an additional [11C]carfentanil PET session after the first sucrose exposure. We calculated voxel-wise binding potentials (BPND) using the cerebellum as a region of non-displaceable binding, analyzed differences with statistical non-parametric mapping, and performed a regional analysis. After 12 days of sucrose access, BPND of both tracers had declined significantly in striatum, nucleus accumbens, thalamus, amygdala, cingulate cortex and prefrontal cortex, consistent with down-regulation of receptor densities. After a single exposure to sucrose, we found decreased binding of [11C]carfentanil in nucleus accumbens and cingulate cortex, consistent with opioid release. The lower availability of opioid and dopamine receptors may explain the addictive potential associated with intake of sucrose.
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Affiliation(s)
- Michael Winterdahl
- Department of Nuclear Medicine and PET Center, Aarhus University, Aarhus, Denmark
| | - Ove Noer
- Department of Nuclear Medicine and PET Center, Aarhus University, Aarhus, Denmark
| | - Dariusz Orlowski
- Department of Neurosurgery and CENSE, Aarhus University Hospital, Aarhus, Denmark
| | - Anna C Schacht
- Department of Nuclear Medicine and PET Center, Aarhus University, Aarhus, Denmark
| | - Steen Jakobsen
- Department of Nuclear Medicine and PET Center, Aarhus University, Aarhus, Denmark
| | - Aage K O Alstrup
- Department of Nuclear Medicine and PET Center, Aarhus University, Aarhus, Denmark
| | - Albert Gjedde
- Department of Nuclear Medicine and PET Center, Aarhus University, Aarhus, Denmark.,Department of Nuclear Medicine, University of Southern Denmark & Odense University Hospital, Odense, Denmark.,Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark.,Department of Neurology and Neurosurgery, McGill University, Montreal, Canada
| | - Anne M Landau
- Department of Nuclear Medicine and PET Center, Aarhus University, Aarhus, Denmark. .,Translational Neuropsychiatry Unit, Aarhus University, Aarhus, Denmark.
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30
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Colom M, Vidal B, Zimmer L. Is There a Role for GPCR Agonist Radiotracers in PET Neuroimaging? Front Mol Neurosci 2019; 12:255. [PMID: 31680859 PMCID: PMC6813225 DOI: 10.3389/fnmol.2019.00255] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 10/02/2019] [Indexed: 12/30/2022] Open
Abstract
Positron emission tomography (PET) is a molecular imaging modality that enables in vivo exploration of metabolic processes and especially the pharmacology of neuroreceptors. G protein-coupled receptors (GPCRs) play an important role in numerous pathophysiologic disorders of the central nervous system. Thus, they are targets of choice in PET imaging to bring proof concept of change in density in pathological conditions or in pharmacological challenge. At present, most radiotracers are antagonist ligands. In vitro data suggest that properties differ between GPCR agonists and antagonists: antagonists bind to receptors with a single affinity, whereas agonists are characterized by two different affinities: high affinity for receptors that undergo functional coupling to G-proteins, and low affinity for those that are not coupled. In this context, agonist radiotracers may be useful tools to give functional images of GPCRs in the brain, with high sensitivity to neurotransmitter release. Here, we review all existing PET radiotracers used from animals to humans and their role for understanding the ligand-receptor paradigm of GPCR in comparison with corresponding antagonist radiotracers.
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Affiliation(s)
- Matthieu Colom
- Lyon Neuroscience Research Center, INSERM, CNRS, Université de Lyon, Lyon, France.,CERMEP, Hospices Civils de Lyon, Bron, France
| | - Benjamin Vidal
- Lyon Neuroscience Research Center, INSERM, CNRS, Université de Lyon, Lyon, France
| | - Luc Zimmer
- Lyon Neuroscience Research Center, INSERM, CNRS, Université de Lyon, Lyon, France.,CERMEP, Hospices Civils de Lyon, Bron, France.,Institut National des Sciences et Techniques Nucléaires, CEA Saclay, Gif-sur-Yvette, France
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31
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Ashok AH, Myers J, Reis Marques T, Rabiner EA, Howes OD. Reduced mu opioid receptor availability in schizophrenia revealed with [ 11C]-carfentanil positron emission tomographic Imaging. Nat Commun 2019; 10:4493. [PMID: 31582737 PMCID: PMC6776653 DOI: 10.1038/s41467-019-12366-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 09/04/2019] [Indexed: 12/16/2022] Open
Abstract
Negative symptoms, such as amotivation and anhedonia, are a major cause of functional impairment in schizophrenia. There are currently no licensed treatments for negative symptoms, highlighting the need to understand the molecular mechanisms underlying them. Mu-opioid receptors (MOR) in the striatum play a key role in hedonic processing and reward function and are reduced post-mortem in schizophrenia. However, it is unknown if mu-opioid receptor availability is altered in-vivo or related to negative symptoms in schizophrenia. Using [11 C]-carfentanil positron emission tomography (PET) scans in 19 schizophrenia patients and 20 age-matched healthy controls, here we show a significantly lower MOR availability in patients with schizophrenia in the striatum (Cohen's d = 0.7), and the hedonic network. In addition, we report a marked global increase in inter-regional covariance of MOR availability in schizophrenia, largely due to increased cortical-subcortical covariance.
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Affiliation(s)
- Abhishekh H Ashok
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, London, UK.,Faculty of Medicine, Psychiatric Imaging Group, Institute of Clinical Sciences (ICS), Imperial College London, London, UK.,Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, UK.,Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.,Department of Radiology, University of Cambridge, Cambridge, UK
| | - Jim Myers
- Faculty of Medicine, Imperial College London, London, UK
| | - Tiago Reis Marques
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, London, UK.,Faculty of Medicine, Psychiatric Imaging Group, Institute of Clinical Sciences (ICS), Imperial College London, London, UK.,Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, UK
| | - Eugenii A Rabiner
- Invicro, London, UK.,Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, UK
| | - Oliver D Howes
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, Imperial College London, London, UK. .,Faculty of Medicine, Psychiatric Imaging Group, Institute of Clinical Sciences (ICS), Imperial College London, London, UK. .,Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, UK.
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32
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Kehinde F, Oduyeye O, Mohammed R. Could the link between drug addiction in adulthood and substance use in adolescence result from a blurring of the boundaries between incentive and hedonic processes? Subst Abuse Rehabil 2019; 10:33-46. [PMID: 31372088 PMCID: PMC6634303 DOI: 10.2147/sar.s202996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Accepted: 04/30/2019] [Indexed: 11/23/2022] Open
Abstract
There is a broad consensus that the development of drug addiction in adulthood is closely linked to the onset of drug use in adolescence. However, the relationship between drug exposure during adolescence and subsequent vulnerability to addiction is yet to be fully understood. This review will first use evidence from adult studies on reward and addiction to give an up-to-date reference point of normal reward-circuitry and the maladaptive changes that later occur in addiction. This will then be compared with current evidence from adolescent studies on reward-circuitry. Similarities between the reward processes governing characteristic behavioral traits in adolescence and the reward profile in adult addiction could help to explain why the risk of later developing addiction is increased when substance use is initiated in adolescence. We argue that the age of onset is a major risk factor in the development of substance use disorder due to a blurring of the boundaries between incentive and hedonic processes, which occurs during adolescence. A deeper understanding of the processes that mediate this blurring could open new avenues for the prevention and treatment of adult drug addiction.
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Affiliation(s)
- Fiona Kehinde
- Faculty of Medicine, University of Cambridge, Cambridge, UK
| | - Opeoluwa Oduyeye
- Faculty of Medicine, Imperial College School of Medicine, London, UK
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33
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34
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Stice E, Burger K. Neural vulnerability factors for obesity. Clin Psychol Rev 2019; 68:38-53. [PMID: 30587407 PMCID: PMC6397091 DOI: 10.1016/j.cpr.2018.12.002] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 10/05/2018] [Accepted: 12/17/2018] [Indexed: 01/09/2023]
Abstract
Multiple theories identify neural vulnerability factors that may increase risk for overeating and weight gain. Early cross-sectional neuroimaging studies were unable to determine whether aberrant neural responsivity was a risk factor for or a consequence of overeating. More recent obesity risk, prospective, repeated-measures, and experimental neuroimaging studies with humans have advanced knowledge of etiologic processes and neural plasticity resulting from overeating. Herein, we review evidence from these more rigorous human neuroimaging studies, in conjunction with behavioral measures reflecting neural function, as well as experiments with animals that investigated neural vulnerability theories for overeating. Findings provide support for the reward surfeit theory that posits that individuals at risk for obesity initially show hyper-responsivity of reward circuitry to high-calorie food tastes, which theoretically drives elevated intake of such foods. However, findings provide little support for the reward deficit theory that postulates that individuals at risk for obesity show an initial hypo-responsivity of reward circuitry that motives overeating. Further, results provide support for the incentive sensitization and dynamic vulnerability theories that propose that overconsumption of high-calorie foods results in increased reward and attention region responsivity to cues that are associated with hedonic reward from intake of these high-calorie foods via conditioning, as well as a simultaneous decrease in reward region responsivity to high-calorie food tastes. However, there is little evidence that this induced reduction in reward region response to high-calorie food tastes drives an escalation in overeating. Finally, results provide support for the theory that an initial deficit in inhibitory control and a bias for immediate reward contribute to overconsumption of high-calorie foods. Findings imply that interventions that reduce reward and attention region responsivity to food cues and increase inhibitory control should reduce overeating and excessive weight gain, an intervention theory that is receiving support in randomized trials.
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Affiliation(s)
- Eric Stice
- Oregon Research Institute, Eugene, OR, USA.
| | - Kyle Burger
- University of North Carolina, Chapel Hill, NC, USA
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35
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He Y, Lu Y, Shen Y, Wu F, Xu X, Kong E, Huang Z, Sun Y, Yu W. Transgenic increase in the β-endorphin concentration in cerebrospinal fluid alleviates morphine-primed relapse behavior through the μ opioid receptor in rats. J Med Virol 2019; 91:1158-1167. [PMID: 30701563 PMCID: PMC6593851 DOI: 10.1002/jmv.25415] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 11/06/2018] [Accepted: 11/28/2018] [Indexed: 11/11/2022]
Abstract
BACKGROUND Opioid-primed relapse is a global burden. Although current strategies have improved, optimal therapy is urgently needed. METHODS A recombinant adenovirus (Ad-NEP) expressing β-endorphin (β-EP) was designed and injected intracerebroventricularly (icv) into the right lateral ventricle in rats. Spatial and temporal β-EP expression in the lateral ventricle wall, subventricular zone and adjacent choroid plexus and the β-EP concentration in the cerebrospinal fluid (CSF) were observed during a 21-day period. A morphine priming-induced conditioned place preference (CPP) rat model was established. The β-EP-ir neuron counts, CSF β-EP concentration, and CPP score, which were used to evaluate morphine-primed reinstatement following extinction, were recorded 7 days after the icv injection. Additionally, the rats were pretreated with the irreversible μ opioid receptor antagonist β-funaltrexamine (β-FNA) and the selective κ opioid receptor antagonist nor-binaltorphimine (nor-BNI) to identify the receptor-dependent mechanism. RESULTS Both peak β-EP expression in target neurons and the peak CSF β-EP concentration occurred 7 to 8 days after Ad-NEP icv injection. The sustainable increase in the CSF β-EP concentration was correlated with a decrease in the CPP score 7 days after the Ad-NEP icv injection. Furthermore, reinstatement was almost reversed by β-FNA pretreatment 24 hours before the behavioral test, but nor-BNI had little effect. CONCLUSION The increasing cerebrospinal fluid β-endorphin concentrations showed that the therapeutic effect on opioid relapse occurred predominantly through a μ opioid receptor-dependent mechanism. The Ad-NEP adenovirus can be considered an alternative therapy for opioid relapse.
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Affiliation(s)
- Yan He
- Department of Anesthesiology & Intensive Care, Eastern Hepatobiliary Hospital, Second Military Medical University, Shanghai, China.,Department of Anesthesiology, Fuzhou General Hospital of PLA, Fuzhou, Fujian, China
| | - Yugang Lu
- Department of Anesthesiology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China
| | - Yang Shen
- Drug and Equipment Section, 442 Clinic Department of Fuzhous General Hospital of PLA, Ningde, Fujian, China
| | - Feixiang Wu
- Department of Anesthesiology & Intensive Care, Eastern Hepatobiliary Hospital, Second Military Medical University, Shanghai, China
| | - Xuewu Xu
- Department of Anesthesiology, 306 Hospital of PLA, Beijing, China
| | - Erliang Kong
- Department of Anesthesiology & Intensive Care, Eastern Hepatobiliary Hospital, Second Military Medical University, Shanghai, China
| | - Zhangxiang Huang
- Pain Clinic of First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Yuming Sun
- Department of Anesthesiology & Intensive Care, Eastern Hepatobiliary Hospital, Second Military Medical University, Shanghai, China
| | - Weifeng Yu
- Department of Anesthesiology & Intensive Care, Eastern Hepatobiliary Hospital, Second Military Medical University, Shanghai, China
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Abstract
Understanding how the brain translates a structured sequence of sounds, such as music, into a pleasant and rewarding experience is a fascinating question which may be crucial to better understand the processing of abstract rewards in humans. Previous neuroimaging findings point to a challenging role of the dopaminergic system in music-evoked pleasure. However, there is a lack of direct evidence showing that dopamine function is causally related to the pleasure we experience from music. We addressed this problem through a double blind within-subject pharmacological design in which we directly manipulated dopaminergic synaptic availability while healthy participants (n = 27) were engaged in music listening. We orally administrated to each participant a dopamine precursor (levodopa), a dopamine antagonist (risperidone), and a placebo (lactose) in three different sessions. We demonstrate that levodopa and risperidone led to opposite effects in measures of musical pleasure and motivation: while the dopamine precursor levodopa, compared with placebo, increased the hedonic experience and music-related motivational responses, risperidone led to a reduction of both. This study shows a causal role of dopamine in musical pleasure and indicates that dopaminergic transmission might play different or additive roles than the ones postulated in affective processing so far, particularly in abstract cognitive activities.
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Shalgunov V, van Waarde A, Booij J, Michel MC, Dierckx RAJO, Elsinga PH. Hunting for the high-affinity state of G-protein-coupled receptors with agonist tracers: Theoretical and practical considerations for positron emission tomography imaging. Med Res Rev 2018; 39:1014-1052. [PMID: 30450619 PMCID: PMC6587759 DOI: 10.1002/med.21552] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 10/02/2018] [Accepted: 10/19/2018] [Indexed: 12/15/2022]
Abstract
The concept of the high‐affinity state postulates that a certain subset of G‐protein‐coupled receptors is primarily responsible for receptor signaling in the living brain. Assessing the abundance of this subset is thus potentially highly relevant for studies concerning the responses of neurotransmission to pharmacological or physiological stimuli and the dysregulation of neurotransmission in neurological or psychiatric disorders. The high‐affinity state is preferentially recognized by agonists in vitro. For this reason, agonist tracers have been developed as tools for the noninvasive imaging of the high‐affinity state with positron emission tomography (PET). This review provides an overview of agonist tracers that have been developed for PET imaging of the brain, and the experimental paradigms that have been developed for the estimation of the relative abundance of receptors configured in the high‐affinity state. Agonist tracers appear to be more sensitive to endogenous neurotransmitter challenge than antagonists, as was originally expected. However, other expectations regarding agonist tracers have not been fulfilled. Potential reasons for difficulties in detecting the high‐affinity state in vivo are discussed.
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Affiliation(s)
- Vladimir Shalgunov
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Aren van Waarde
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Jan Booij
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centers, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Martin C Michel
- Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany
| | - Rudi A J O Dierckx
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.,Department of Nuclear Medicine, Ghent University, University Hospital, Ghent, Belgium
| | - Philip H Elsinga
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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Kohno M, Dennis LE, McCready H, Schwartz DL, Hoffman WF, Korthuis PT. A preliminary randomized clinical trial of naltrexone reduces striatal resting state functional connectivity in people with methamphetamine use disorder. Drug Alcohol Depend 2018; 192:186-192. [PMID: 30266003 PMCID: PMC6200637 DOI: 10.1016/j.drugalcdep.2018.07.045] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 07/31/2018] [Accepted: 07/31/2018] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Naltrexone has been shown to attenuate craving and the subjective effects of methamphetamine. Although naltrexone has modulatory effects on neural activity at dopaminergic synapses, the effect on striatal connectivity is unclear. As methamphetamine use is associated with greater resting-state functional connectivity (RSFC) in the dopaminergic system, we examined whether extended-release naltrexone (XR-NTX) can normalize striatal connectivity and whether changes in RSFC are associated with changes in craving and methamphetamine use. METHODS Thirty-seven participants in or seeking treatment for methamphetamine use disorder took part in this clinical trial at a university-based research clinic between May 2013 and March 2015 (Clinicaltrials.gov NCT01822132). Participants were randomized by a random number generator to a single four-week injection of XR-NTX or placebo. Functional magnetic resonance imaging (fMRI) and self-reported measures of craving and methamphetamine use were conducted before and after double-blinded randomization. FINDINGS There was a significant reduction in methamphetamine use in the naltrexone group and a significant treatment-by-time interaction on RSFC between the ventral striatum, amygdala, hippocampus, and midbrain. Connectivity was significantly reduced over time in participants randomized to naltrexone but unchanged in those randomized to placebo (p < 0.05, whole-brain corrected). Interactions between treatment and changes in connectivity show that significant reductions in connectivity were associated with reductions in methamphetamine use. CONCLUSIONS Neurobiological deficits associated with methamphetamine use may undermine the efficacy of pharmacotherapies that directly target the dopamine reward system. Naltrexone, via antagonism of indirect mu-opioid effects on dopamine neurons, may attenuate reward system connectivity and aid in methamphetamine use treatment.
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Affiliation(s)
- Milky Kohno
- Department of Psychiatry, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239, USA; Department of Behavioral Neuroscience, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239, USA; Research and Development Service, Veterans Affairs Portland Health Care System, 3710 SW US Veterans Hospital Rd., Portland, OR 97239, USA; Methamphetamine Abuse Research Center, Oregon Health and Science University and Veterans Affairs Portland Health Care System, 3181 SW Sam Jackson Park Rd., Portland, OR 97239, USA.
| | - Laura E Dennis
- Department of Psychiatry, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239, USA; Research and Development Service, Veterans Affairs Portland Health Care System, 3710 SW US Veterans Hospital Rd., Portland, OR 97239, USA
| | - Holly McCready
- Department of Psychiatry, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239, USA; Research and Development Service, Veterans Affairs Portland Health Care System, 3710 SW US Veterans Hospital Rd., Portland, OR 97239, USA
| | - Daniel L Schwartz
- Department of Neurology, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239, USA; Advanced Imaging Research Center, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239, USA
| | - William F Hoffman
- Department of Psychiatry, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239, USA; Department of Behavioral Neuroscience, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239, USA; Research and Development Service, Veterans Affairs Portland Health Care System, 3710 SW US Veterans Hospital Rd., Portland, OR 97239, USA; Mental Health Division, Veterans Affairs Portland Health Care System, 3710 SW US Veterans Hospital Rd., Portland, OR 97239, USA; Methamphetamine Abuse Research Center, Oregon Health and Science University and Veterans Affairs Portland Health Care System, 3181 SW Sam Jackson Park Rd., Portland, OR 97239, USA
| | - P Todd Korthuis
- Section of Addiction Medicine, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239, USA
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Vérin M, Benquet P. The move: When neurosciences teach us to better teach neurosciences. J Neurol Sci 2018; 391:149-150. [PMID: 29910129 DOI: 10.1016/j.jns.2018.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 06/06/2018] [Indexed: 01/25/2023]
Affiliation(s)
- Marc Vérin
- Behavior and Basal Ganglia Research Unit (EA4712), University of Rennes 1, Rennes, France; Department of Neurology, Rennes University Hospital, Rennes, France; Institut des Neurosciences Cliniques de Rennes, Rennes, France.
| | - Pascal Benquet
- Institut des Neurosciences Cliniques de Rennes, Rennes, France; INSERM U1099, LTSI, University of Rennes 1, Rennes, France
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Majuri J, Joutsa J, Arponen E, Forsback S, Kaasinen V. Dopamine synthesis capacity correlates with µ-opioid receptor availability in the human basal ganglia: A triple-tracer PET study. Neuroimage 2018; 183:1-6. [PMID: 30077742 DOI: 10.1016/j.neuroimage.2018.07.069] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 07/20/2018] [Accepted: 07/31/2018] [Indexed: 12/16/2022] Open
Abstract
Animal studies have suggested that dopamine and opioid neurotransmitter systems interact in brain regions that are relevant for reward functions, but data in humans are very limited. The interaction is potentially important in disorders affecting these neurotransmitter systems, such as addiction. Here, we investigated whether subcortical μ-opioid receptor (MOR) availability and presynaptic dopamine synthesis capacity are correlated in the healthy human brain or in pathological gamblers (PGs) using positron emission tomography with 6-[18F]fluoro-l-dopa and [11C]carfentanil. The specificity of the findings was further investigated by including a serotonin transporter ligand, [11C]MADAM, as a negative control. Thirteen PG patients and 15 age-, sex- and weight-matched controls underwent the scans. In both groups, presynaptic dopamine synthesis capacity was associated with MOR availability in the putamen, caudate nucleus and globus pallidus. No similar associations were observed between dopamine synthesis capacity and [11C]MADAM binding, supporting a specific interplay between presynaptic dopamine neurotransmission and opioid receptor function in the basal ganglia. Correlations were similar between the groups, suggesting that the dopamine-opioid link is general and unaffected by behavioral addiction. The results provide in vivo human evidence of a connection between endogenous opioid and dopamine signaling in the brain.
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Affiliation(s)
- Joonas Majuri
- Division of Clinical Neurosciences, Turku University Hospital, PO Box 52, FIN-20521, Turku, Finland; Department of Neurology, University of Turku, PO Box 52, FIN-20521, Turku, Finland; Turku PET Centre, University of Turku, PO Box 52, FIN-20521, Turku, Finland.
| | - Juho Joutsa
- Division of Clinical Neurosciences, Turku University Hospital, PO Box 52, FIN-20521, Turku, Finland; Department of Neurology, University of Turku, PO Box 52, FIN-20521, Turku, Finland; Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States; Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
| | - Eveliina Arponen
- Turku PET Centre, University of Turku, PO Box 52, FIN-20521, Turku, Finland
| | - Sarita Forsback
- Turku PET Centre, University of Turku, PO Box 52, FIN-20521, Turku, Finland
| | - Valtteri Kaasinen
- Division of Clinical Neurosciences, Turku University Hospital, PO Box 52, FIN-20521, Turku, Finland; Department of Neurology, University of Turku, PO Box 52, FIN-20521, Turku, Finland; Turku PET Centre, University of Turku, PO Box 52, FIN-20521, Turku, Finland
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41
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Saanijoki T, Nummenmaa L, Tuulari JJ, Tuominen L, Arponen E, Kalliokoski KK, Hirvonen J. Aerobic exercise modulates anticipatory reward processing via the μ-opioid receptor system. Hum Brain Mapp 2018; 39:3972-3983. [PMID: 29885086 DOI: 10.1002/hbm.24224] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 04/20/2018] [Accepted: 05/10/2018] [Indexed: 01/18/2023] Open
Abstract
Physical exercise modulates food reward and helps control body weight. The endogenous µ-opioid receptor (MOR) system is involved in rewarding aspects of both food and physical exercise, yet interaction between endogenous opioid release following exercise and anticipatory food reward remains unresolved. Here we tested whether exercise-induced opioid release correlates with increased anticipatory reward processing in humans. We scanned 24 healthy lean men after rest and after a 1 h session of aerobic exercise with positron emission tomography (PET) using MOR-selective radioligand [11 C]carfentanil. After both PET scans, the subjects underwent a functional magnetic resonance imaging (fMRI) experiment where they viewed pictures of palatable versus nonpalatable foods to trigger anticipatory food reward responses. Exercise-induced changes in MOR binding in key regions of reward circuit (amygdala, thalamus, ventral and dorsal striatum, and orbitofrontal and cingulate cortices) were used to predict the changes in anticipatory reward responses in fMRI. Exercise-induced changes in MOR binding correlated negatively with the exercise-induced changes in neural anticipatory food reward responses in orbitofrontal and cingulate cortices, insula, ventral striatum, amygdala, and thalamus: higher exercise-induced opioid release predicted higher brain responses to palatable versus nonpalatable foods. We conclude that MOR activation following exercise may contribute to the considerable interindividual variation in food craving and consumption after exercise, which might promote compensatory eating and compromise weight control.
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Affiliation(s)
| | - Lauri Nummenmaa
- Turku PET Centre, University of Turku, Turku, Finland.,Department of Psychology, University of Turku, Turku, Finland
| | | | - Lauri Tuominen
- Turku PET Centre, University of Turku, Turku, Finland.,Department of Psychiatry, Massachusetts General Hospital, Boston, Massachusetts.,Harvard Medical School, Boston, Massachusetts
| | | | | | - Jussi Hirvonen
- Turku PET Centre, University of Turku, Turku, Finland.,Department of Radiology, Turku University Hospital, Turku, Finland
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Faraone SV. The pharmacology of amphetamine and methylphenidate: Relevance to the neurobiology of attention-deficit/hyperactivity disorder and other psychiatric comorbidities. Neurosci Biobehav Rev 2018; 87:255-270. [PMID: 29428394 DOI: 10.1016/j.neubiorev.2018.02.001] [Citation(s) in RCA: 297] [Impact Index Per Article: 49.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 01/25/2018] [Accepted: 02/05/2018] [Indexed: 12/20/2022]
Abstract
Psychostimulants, including amphetamines and methylphenidate, are first-line pharmacotherapies for individuals with attention-deficit/hyperactivity disorder (ADHD). This review aims to educate physicians regarding differences in pharmacology and mechanisms of action between amphetamine and methylphenidate, thus enhancing physician understanding of psychostimulants and their use in managing individuals with ADHD who may have comorbid psychiatric conditions. A systematic literature review of PubMed was conducted in April 2017, focusing on cellular- and brain system-level effects of amphetamine and methylphenidate. The primary pharmacologic effect of both amphetamine and methylphenidate is to increase central dopamine and norepinephrine activity, which impacts executive and attentional function. Amphetamine actions include dopamine and norepinephrine transporter inhibition, vesicular monoamine transporter 2 (VMAT-2) inhibition, and monoamine oxidase activity inhibition. Methylphenidate actions include dopamine and norepinephrine transporter inhibition, agonist activity at the serotonin type 1A receptor, and redistribution of the VMAT-2. There is also evidence for interactions with glutamate and opioid systems. Clinical implications of these actions in individuals with ADHD with comorbid depression, anxiety, substance use disorder, and sleep disturbances are discussed.
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Affiliation(s)
- Stephen V Faraone
- Departments of Psychiatry and of Neuroscience and Physiology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY, United States; K.G. Jebsen Centre for Research on Neuropsychiatric Disorders, University of Bergen, Bergen, Norway.
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43
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Saanijoki T, Tuominen L, Tuulari JJ, Nummenmaa L, Arponen E, Kalliokoski K, Hirvonen J. Opioid Release after High-Intensity Interval Training in Healthy Human Subjects. Neuropsychopharmacology 2018; 43:246-254. [PMID: 28722022 PMCID: PMC5729560 DOI: 10.1038/npp.2017.148] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 07/10/2017] [Accepted: 07/11/2017] [Indexed: 12/18/2022]
Abstract
Central opioidergic mechanisms may modulate the positive effects of physical exercise such as mood elevation and stress reduction. How exercise intensity and concomitant effective changes affect central opioidergic responses is unknown. We studied the effects of acute physical exercise on the cerebral μ-opioid receptors (MOR) of 22 healthy recreationally active males using positron emission tomography (PET) and the MOR-selective radioligand [11C]carfentanil. MOR binding was measured in three conditions on separate days: after a 60-min aerobic moderate-intensity exercise session, after a high-intensity interval training (HIIT) session, and after rest. Mood was measured repeatedly throughout the experiment. HIIT significantly decreased MOR binding selectively in the frontolimbic regions involved in pain, reward, and emotional processing (thalamus, insula, orbitofrontal cortex, hippocampus, and anterior cingulate cortex). Decreased binding correlated with increased negative emotionality. Moderate-intensity exercise did not change MOR binding, although increased euphoria correlated with decreased receptor binding. These observations, consistent with endogenous opioid release, highlight the role of the μ-opioid system in mediating affective responses to high-intensity training as opposed to recreational moderate physical exercise.
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Affiliation(s)
| | - Lauri Tuominen
- Turku PET Centre, University of Turku, Turku, Finland,Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA,Harvard Medical School, Boston, MA, USA
| | | | - Lauri Nummenmaa
- Turku PET Centre, University of Turku, Turku, Finland,Department of Psychology, University of Turku, Turku, Finland
| | | | | | - Jussi Hirvonen
- Turku PET Centre, University of Turku, Turku, Finland,Department of Radiology, Turku University Hospital and University of Turku, Turku, Finland,Department of Radiology and Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, Turku FIN-20520, Finland, Tel: +358 50 585 8865, Fax: +358 2 313 7908, E-mail:
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Thobois S, Brefel-Courbon C, Le Bars D, Sgambato-Faure V. Molecular Imaging of Opioid System in Idiopathic Parkinson's Disease. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2018; 141:275-303. [DOI: 10.1016/bs.irn.2018.07.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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45
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Baldo BA. Prefrontal Cortical Opioids and Dysregulated Motivation: A Network Hypothesis. Trends Neurosci 2017; 39:366-377. [PMID: 27233653 DOI: 10.1016/j.tins.2016.03.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 03/04/2016] [Accepted: 03/07/2016] [Indexed: 02/06/2023]
Abstract
Loss of inhibitory control over appetitively motivated behavior occurs in multiple psychiatric disorders, including drug abuse, behavioral addictions, and eating disorders with binge features. In this opinion article, novel actions of μ-opioid peptides in the prefrontal cortex (PFC) that could contribute to inhibitory control deficits will be discussed. Evidence has accrued to suggest that excessive intra-PFC μ-opioid receptor (μ-OR) signaling alters the PFC response to excitatory drive, resulting in supernormal and incoherent recruitment of multiple PFC output pathways. Affected pathways include functionally opposed PFC→hypothalamus 'appetitive driver' and PFC→striatum 'appetitive limiter' projections. This network perturbation engenders disorganized, impulsive appetitive responses. Evidence supporting this hypothesis from human imaging and animal studies will be discussed, and combinatorial drug treatments targeting μ-ORs and specific PFC subcortical targets will be explored.
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Affiliation(s)
- Brian A Baldo
- Department of Psychiatry, University of Wisconsin-Madison School of Medicine and Public Health, 6001 Research Park Blvd, Madison, WI 53719, USA.
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46
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Nestor LJ, Murphy A, McGonigle J, Orban C, Reed L, Taylor E, Flechais R, Paterson LM, Smith D, Bullmore ET, Ersche KD, Suckling J, Tait R, Elliott R, Deakin B, Rabiner I, Lingford-Hughes A, Nutt DJ, Sahakian B, Robbins TW. Acute naltrexone does not remediate fronto-striatal disturbances in alcoholic and alcoholic polysubstance-dependent populations during a monetary incentive delay task. Addict Biol 2017; 22:1576-1589. [PMID: 27600363 DOI: 10.1111/adb.12444] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 07/29/2016] [Accepted: 08/01/2016] [Indexed: 11/29/2022]
Abstract
There is a concerted research effort to investigate brain mechanisms underlying addiction processes that may predicate the development of new compounds for treating addiction. One target is the brain's opioid system, because of its role in the reinforcing effects of substances of abuse. Substance-dependent populations have increased numbers of the mu opioid receptor (MOR) in fronto-striatal regions that predict drug relapse, and demonstrate disturbances in these regions during the processing of non-drug rewards. Naltrexone is currently licensed for alcohol and opiate dependence, and may remediate such disturbances through the blockade of MORs in fronto-striatal reward circuitry. Therefore, we examined the potential acute modulating effects of naltrexone on the anticipation of, and instrumental responding for, non-drug rewards in long-term abstinent alcoholics, alcoholic poly substance-dependent individuals and controls using a monetary incentive delay (MID) task during a randomized double blind placebo controlled functional MRI study. We report that the alcoholic poly substance-dependent group exhibited slower and less accurate instrumental responding compared to alcoholics and controls that was less evident after acute naltrexone treatment. However, naltrexone treatment was unable to remediate disturbances within fronto-striatal regions during reward anticipation and 'missed' rewards in either substance-dependent group. While we have not been able to identify the underlying neural mechanisms for improvement observed with naltrexone in the alcoholic poly-substance dependent group, we can confirm that both substance-dependent groups exhibit substantial neural deficits during an MID task, despite being in long-term abstinence.
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Affiliation(s)
- Liam J Nestor
- Centre for Neuropsychopharmacology; Imperial College London; UK
- Department of Psychiatry; University of Cambridge; UK
| | - Anna Murphy
- Neuroscience and Psychiatry Unit; University of Manchester; UK
| | - John McGonigle
- Centre for Neuropsychopharmacology; Imperial College London; UK
| | - Csaba Orban
- Centre for Neuropsychopharmacology; Imperial College London; UK
| | - Laurence Reed
- Centre for Neuropsychopharmacology; Imperial College London; UK
| | - Eleanor Taylor
- Neuroscience and Psychiatry Unit; University of Manchester; UK
| | - Remy Flechais
- Centre for Neuropsychopharmacology; Imperial College London; UK
| | | | - Dana Smith
- Department of Psychiatry; University of Cambridge; UK
- Department of Psychology; University of Cambridge; UK
| | | | - Karen D Ersche
- Department of Psychiatry; University of Cambridge; UK
- Department of Psychology; University of Cambridge; UK
| | - John Suckling
- Department of Psychiatry; University of Cambridge; UK
| | - Roger Tait
- Department of Psychiatry; University of Cambridge; UK
| | - Rebecca Elliott
- Neuroscience and Psychiatry Unit; University of Manchester; UK
| | - Bill Deakin
- Neuroscience and Psychiatry Unit; University of Manchester; UK
| | | | | | - David J Nutt
- Centre for Neuropsychopharmacology; Imperial College London; UK
| | - Barbara Sahakian
- Department of Psychiatry; University of Cambridge; UK
- Department of Psychology; University of Cambridge; UK
| | - Trevor W Robbins
- Department of Psychiatry; University of Cambridge; UK
- Department of Psychology; University of Cambridge; UK
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A commentary on the associations among ‘food addiction’, binge eating disorder, and obesity: Overlapping conditions with idiosyncratic clinical features. Appetite 2017; 115:3-8. [DOI: 10.1016/j.appet.2016.11.001] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Revised: 10/16/2016] [Accepted: 11/01/2016] [Indexed: 02/07/2023]
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48
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Eikemo M, Biele G, Willoch F, Thomsen L, Leknes S. Opioid Modulation of Value-Based Decision-Making in Healthy Humans. Neuropsychopharmacology 2017; 42:1833-1840. [PMID: 28294136 PMCID: PMC5520785 DOI: 10.1038/npp.2017.58] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 02/20/2017] [Accepted: 03/07/2017] [Indexed: 01/08/2023]
Abstract
Modifying behavior to maximize reward is integral to adaptive decision-making. In rodents, the μ-opioid receptor (MOR) system encodes motivation and preference for high-value rewards. Yet it remains unclear whether and how human MORs contribute to value-based decision-making. We reasoned that if the human MOR system modulates value-based choice, this would be reflected by opposite effects of agonist and antagonist drugs. In a double-blind pharmacological cross-over study, 30 healthy men received morphine (10 mg), placebo, and the opioid antagonist naltrexone (50 mg). They completed a two-alternative decision-making task known to induce a considerable bias towards the most frequently rewarded response option. To quantify MOR involvement in this bias, we fitted accuracy and reaction time data with the drift-diffusion model (DDM) of decision-making. The DDM analysis revealed the expected bidirectional drug effects for two decision subprocesses. MOR stimulation with morphine increased the preference for the stimulus with high-reward probability (shift in starting point). Compared to placebo, morphine also increased, and naltrexone reduced, the efficiency of evidence accumulation. Since neither drug affected motor-coordination, speed-accuracy trade-off, or subjective state (indeed participants were still blinded after the third session), we interpret the MOR effects on evidence accumulation efficiency as a consequence of changes in effort exerted in the task. Together, these findings support a role for the human MOR system in value-based choice by tuning decision-making towards high-value rewards across stimulus domains.
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Affiliation(s)
- Marie Eikemo
- The Department of Psychology, University of Oslo, Oslo, Norway,Norwegian Center for Addiction Research, Department of Clinical Medicine, University of Oslo, Oslo, Norway,Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway,Norwegian Centre for Addiction Research, University of Oslo, PO BOX 1039 Blindern, Oslo 0315, Norway, Tel: +47 23 36 89 76, Fax: +47 23 36 89 86, E-mail:
| | - Guido Biele
- The Department of Psychology, University of Oslo, Oslo, Norway,Department of Child Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Frode Willoch
- The Department of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Lotte Thomsen
- The Department of Psychology, University of Oslo, Oslo, Norway
| | - Siri Leknes
- The Department of Psychology, University of Oslo, Oslo, Norway,The Intervention Centre, Oslo University Hospital, Oslo, Norway
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Feeding Releases Endogenous Opioids in Humans. J Neurosci 2017; 37:8284-8291. [PMID: 28747384 DOI: 10.1523/jneurosci.0976-17.2017] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 07/06/2017] [Accepted: 07/10/2017] [Indexed: 11/21/2022] Open
Abstract
The endogenous opioid system supports a multitude of functions related to appetitive behavior in humans and animals, and it has been proposed to govern hedonic aspects of feeding thus contributing to the development of obesity. Here we used positron emission tomography to investigate whether feeding results in hedonia-dependent endogenous opioid release in humans. Ten healthy males were recruited for the study. They were scanned with the μ-opioid-specific ligand [11C]carfentanil three times, as follows: after a palatable meal, a nonpalatable meal, and after an overnight fast. Subjective mood, satiety, and circulating hormone levels were measured. Feeding induced significant endogenous opioid release throughout the brain. This response was more pronounced following a nonpalatable meal versus a palatable meal, and independent of the subjective hedonic responses to feeding. We conclude that feeding consistently triggers cerebral opioid release even in the absence of subjective pleasure associated with feeding, suggesting that metabolic and homeostatic rather than exclusively hedonic responses play a role in the feeding-triggered cerebral opioid release.SIGNIFICANCE STATEMENT The endogenous opioid system supports both hedonic and homeostatic functions. It has been proposed that overeating and concomitant opioid release could downregulate opioid receptors and promote the development of obesity. However, it remains unresolved whether feeding leads to endogenous opioid release in humans. We used in vivo positron emission tomography to test whether feeding triggers cerebral opioid release and whether this response is associated with pleasurable sensations. We scanned volunteers using the μ-opioid receptor-specific radioligand [11C]carfentanil three times, as follows: after an overnight fast, after consuming a palatable meal, and after consuming a nonpalatable meal. Feeding led to significant endogenous opioid release, and this occurred also in the absence of feeding-triggered hedonia. Feeding-triggered opioid release thus also reflects metabolic and homeostatic responses rather than hedonic responses exclusively.
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50
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Lamusuo S, Hirvonen J, Lindholm P, Martikainen IK, Hagelberg N, Parkkola R, Taiminen T, Hietala J, Helin S, Virtanen A, Pertovaara A, Jääskeläinen S. Neurotransmitters behind pain relief with transcranial magnetic stimulation - positron emission tomography evidence for release of endogenous opioids. Eur J Pain 2017; 21:1505-1515. [DOI: 10.1002/ejp.1052] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2017] [Indexed: 01/28/2023]
Affiliation(s)
- S. Lamusuo
- Department of Neurology; Turku University Hospital; Finland
- Division of Clinical Neuroscience; University of Turku; Finland
- Turku PET Centre; University of Turku; Finland
| | - J. Hirvonen
- Turku PET Centre; University of Turku; Finland
| | - P. Lindholm
- Department of Neurology; Turku University Hospital; Finland
- Department of Clinical Neurophysiology; Turku University Hospital and University of Turku; Finland
| | - I. K. Martikainen
- Department of Physiology; Turku University Hospital and University of Turku; Finland
| | - N. Hagelberg
- Pain Clinic; Turku University Hospital and University of Turku; Finland
| | - R. Parkkola
- Turku PET Centre; University of Turku; Finland
- Department of Radiology; Turku University Hospital and University of Turku; Finland
| | - T. Taiminen
- Department of Psychiatry; Turku University Hospital and University of Turku; Finland
| | - J. Hietala
- Turku PET Centre; University of Turku; Finland
- Department of Psychiatry; Turku University Hospital and University of Turku; Finland
| | - S. Helin
- Turku PET Centre; University of Turku; Finland
| | - A. Virtanen
- Department of Clinical Neurophysiology; Turku University Hospital and University of Turku; Finland
| | - A. Pertovaara
- Department of Physiology; Faculty of Medicine; University of Helsinki; Finland
| | - S.K. Jääskeläinen
- Department of Clinical Neurophysiology; Turku University Hospital and University of Turku; Finland
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