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Khatib L, Dean JG, Oliva V, Riegner G, Gonzalez NE, Birenbaum J, Cruanes GF, Miller J, Patterson M, Kim HC, Chakravarthy K, Zeidan F. The role of endogenous opioids in mindfulness and sham mindfulness-meditation for the direct alleviation of evoked chronic low back pain: a randomized clinical trial. Neuropsychopharmacology 2024; 49:1069-1077. [PMID: 37985872 PMCID: PMC11109232 DOI: 10.1038/s41386-023-01766-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 10/26/2023] [Accepted: 11/02/2023] [Indexed: 11/22/2023]
Abstract
Chronic low back pain (cLBP) is the most prevalent chronic pain condition. There are no treatments that haven been found to directly assuage evoked cLBP. To this extent, mindfulness-meditation is a promising pain therapy. Yet, it is unclear if meditation can be utilized to directly attenuate evoked chronic pain through endogenous opioids. A double-blind, randomized, and placebo-controlled clinical trial with a drug crossover design examined if mindfulness-meditation, as compared to sham mindfulness-meditation, attenuated straight leg-raise test evoked chronic pain during intravenous (0.15 mg/kg bolus + 0.15 mg/kg/hour maintenance) naloxone (opioid antagonist) and placebo-saline infusion. Fifty-nine individuals with cLBP (mean age = 46 years; 30 females) completed all study procedures. After the pre-intervention pain testing session, patients were randomized to a four-session (20-min/session) mindfulness (n = 30) or sham mindfulness-meditation (n = 29) intervention. After the interventions, mindfulness and sham mindfulness-meditation were associated with significant reductions in back pain during saline and naloxone infusion when compared to rest (non-meditation) in response to the cLBP-evoking straight leg-raise test. These results indicate that meditation directly reduces evoked chronic pain through non-opioidergic processes. Importantly, after the interventions, the mindfulness group reported significantly lower straight leg-raise induced pain than the sham mindfulness-meditation group during rest (non-meditation) and meditation. Mindfulness and sham mindfulness-meditation training was also associated with significantly lower Brief Pain Inventory severity and interference scores. The pain-relieving effects of mindfulness meditation were more pronounced than a robust sham-mindfulness meditation intervention, suggesting that non-reactive appraisal processes may be uniquely associated with improvements in chronic low-back pain.Trial Registration: ClinicalTrials.gov identifier: NCT04034004.
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Affiliation(s)
- Lora Khatib
- Department of Anesthesiology, University of California San Diego, La Jolla, CA, USA
| | - Jon G Dean
- Department of Anesthesiology, University of California San Diego, La Jolla, CA, USA
| | - Valeria Oliva
- Department of Anesthesiology, University of California San Diego, La Jolla, CA, USA
| | - Gabriel Riegner
- Department of Anesthesiology, University of California San Diego, La Jolla, CA, USA
| | - Nailea E Gonzalez
- Department of Anesthesiology, University of California San Diego, La Jolla, CA, USA
| | - Julia Birenbaum
- Department of Anesthesiology, University of California San Diego, La Jolla, CA, USA
| | - Gael F Cruanes
- Department of Anesthesiology, University of California San Diego, La Jolla, CA, USA
| | - Jennifer Miller
- Department of Anesthesiology, University of California San Diego, La Jolla, CA, USA
| | - Marta Patterson
- Department of Anesthesiology, University of California San Diego, La Jolla, CA, USA
| | - Hyun-Chung Kim
- Department of Anesthesiology, University of California San Diego, La Jolla, CA, USA
| | | | - Fadel Zeidan
- Department of Anesthesiology, University of California San Diego, La Jolla, CA, USA.
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2
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Chen Q, Zhao M, Dong J, Yang K. Chronic restraint stress-induced hyperalgesia is modulated by the periaqueductal gray neurons projecting to the rostral ventromedial medulla in mice. Biochem Biophys Res Commun 2024; 710:149875. [PMID: 38604073 DOI: 10.1016/j.bbrc.2024.149875] [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: 03/09/2024] [Accepted: 03/29/2024] [Indexed: 04/13/2024]
Abstract
Stress-induced hyperalgesia (SIH) is induced by repeated or chronic exposure to stressful or uncomfortable environments. However, the neural mechanisms involved in the modulatory effects of the periaqueductal gray (PAG) and its associated loops on SIH development hav e not been elucidated. In the present study, we used chronic restraint stress (CRS)-induced hyperalgesia as a SIH model and manipulated neuronal activity via a pharmacogenetic approach to investigate the neural mechanism underlying the effects of descending pain-modulatory pathways on SIH. We found that activation of PAG neurons alleviates CRS-induced hyperalgesia; on the other hand, PAG neurons inhibition facilitates CRS-induced hyperalgesia. Moreover, this modulatory effect is achieved by the neurons which projecting to the rostral ventromedial medulla (RVM). Our data thus reveal the functional role of the PAG-RVM circuit in SIH and provide analgesic targets in the brain for clinical SIH treatment.
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Affiliation(s)
- Qian Chen
- Department of Anatomy, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, 212013, China
| | - Mingwei Zhao
- Department of Anatomy, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, 212013, China
| | - Jiaxue Dong
- Department of Anatomy, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, 212013, China; Department of Pathology, Xinyang Central Hospital, Xinyang, Henan, 464099, China
| | - Kun Yang
- Department of Anatomy, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, 212013, China; Department of Anatomy, School of Health and Life Sciences, University of Health and Rehabilitation Sciences, Qingdao, Shandong, 266113, China.
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3
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Raghuraman N, White JN, Watson L, Belleï-Rodriguez CÉ, Shafir R, Wang Y, Colloca L. Neuropsychological mechanisms of observational learning in human placebo effects. Psychopharmacology (Berl) 2024:10.1007/s00213-024-06608-7. [PMID: 38743108 DOI: 10.1007/s00213-024-06608-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 05/02/2024] [Indexed: 05/16/2024]
Abstract
Scientific evidence indicates that placebo effects are psychoneurobiological events involving the contribution of distinct central nervous systems and peripheral physiological mechanisms that influence pain perception and other symptoms. Placebo effects can occur without formal conditioning and direct prior experience because crucial information can be acquired through observational learning. Observation of benefits in another person results in placebo effects of a magnitude like those induced by directly experiencing an analgesic benefit. Understanding the psychological mechanisms of observationally induced placebo effects is a complex and multifaceted endeavor. While previous reviews have highlighted various frameworks and models to understand these phenomena, the underlying biological mechanisms have been overlooked. We summarize critically current understanding of its behavioral and neural mechanisms. Understanding the neural mechanisms of hypoalgesia driven by observation can serve as a foundation for future development of novel theoretical and methodological approaches and ultimately, applications.
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Affiliation(s)
- Nandini Raghuraman
- Department of Pain and Translational Symptom Science, University of Maryland School of Nursing, Baltimore, MD, USA
- Graduate Program in Life Sciences, Program in Epidemiology and Human Genetics, University of Maryland School of Medicine, Baltimore, MD, USA
- Placebo Beyond Opinions Center, University of Maryland School of Nursing, Baltimore, USA
| | - Jewel N White
- Department of Pain and Translational Symptom Science, University of Maryland School of Nursing, Baltimore, MD, USA
- Placebo Beyond Opinions Center, University of Maryland School of Nursing, Baltimore, USA
- Graduate Program in Life Sciences, Program in Neuroscience, University of Maryland School of Medicine, Baltimore, USA
| | - Lakota Watson
- Department of Pain and Translational Symptom Science, University of Maryland School of Nursing, Baltimore, MD, USA
- Graduate Program in Life Sciences, Program in Neuroscience, University of Maryland School of Medicine, Baltimore, USA
| | | | - Roni Shafir
- Department of Pain and Translational Symptom Science, University of Maryland School of Nursing, Baltimore, MD, USA
- Placebo Beyond Opinions Center, University of Maryland School of Nursing, Baltimore, USA
| | - Yang Wang
- Department of Pain and Translational Symptom Science, University of Maryland School of Nursing, Baltimore, MD, USA
- Placebo Beyond Opinions Center, University of Maryland School of Nursing, Baltimore, USA
- Center to Advance Chronic Pain Research, University of Maryland, Baltimore, USA
| | - Luana Colloca
- Department of Pain and Translational Symptom Science, University of Maryland School of Nursing, Baltimore, MD, USA.
- Placebo Beyond Opinions Center, University of Maryland School of Nursing, Baltimore, USA.
- Center to Advance Chronic Pain Research, University of Maryland, Baltimore, USA.
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4
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Cheong Y, Lee S, Okazawa H, Kosaka H, Jung M. Effects of functional polymorphisms of opioid receptor mu 1 and catechol-O-methyltransferase on the neural processing of pain. Psychiatry Clin Neurosci 2024; 78:300-308. [PMID: 38403942 DOI: 10.1111/pcn.13648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 11/14/2023] [Accepted: 01/18/2024] [Indexed: 02/27/2024]
Abstract
AIM Pain is reconstructed by brain activities and its subjectivity comes from an interplay of multiple factors. The current study aims to understand the contribution of genetic factors to the neural processing of pain. Focusing on the single-nucleotide polymorphism (SNP) of opioid receptor mu 1 (OPRM1) A118G (rs1799971) and catechol-O-methyltransferase (COMT) val158met (rs4680), we investigated how the two pain genes affect pain processing. METHOD We integrated a genetic approach with functional neuroimaging. We extracted genomic DNA information from saliva samples to genotype the SNP of OPRM1 and COMT. We used a percept-related model, in which two different levels of perceived pain intensities ("low pain: mildly painful" vs "high pain: severely painful") were employed as experimental stimuli. RESULTS Low pain involves a broader network relative to high pain. The distinct effects of pain genes were observed depending on the perceived pain intensity. The effects of low pain were found in supramarginal gyrus, angular gyrus, and anterior cingulate cortex (ACC) for OPRM1 and in middle temporal gyrus for COMT. For high pain, OPRM1 affected the insula and cerebellum, while COMT affected the middle occipital gyrus and ACC. CONCLUSION OPRM1 primarily affects sensory and cognitive components of pain processing, while COMT mainly influences emotional aspects of pain processing. The interaction of the two pain genes was associated with neural patterns coding for high pain and neural activation in the ACC in response to pain. The proteins encoded by the OPRM1 and COMT may contribute to the firing of pain-related neurons in the human ACC, a critical center for subjective pain experience.
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Affiliation(s)
- Yongjeon Cheong
- Cognitive Science Research Group, Korea Brain Research Institute, Daegu, Republic of Korea
| | - Seonkyoung Lee
- Cognitive Science Research Group, Korea Brain Research Institute, Daegu, Republic of Korea
| | - Hidehiko Okazawa
- Research Centre for Child Mental Development, University of Fukui, Eiheiji, Fukui, Japan
- Division of Developmental Higher Brain Functions, Department of Child Development, United Graduate School of Child Development, University of Fukui, Fukui, Japan
| | - Hirotaka Kosaka
- Research Centre for Child Mental Development, University of Fukui, Eiheiji, Fukui, Japan
- Division of Developmental Higher Brain Functions, Department of Child Development, United Graduate School of Child Development, University of Fukui, Fukui, Japan
- Department of Neuropsychiatry, University of Fukui, Fukui, Japan
| | - Minyoung Jung
- Cognitive Science Research Group, Korea Brain Research Institute, Daegu, Republic of Korea
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5
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Szigeti B, Heifets BD. Expectancy Effects in Psychedelic Trials. BIOLOGICAL PSYCHIATRY. COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2024; 9:512-521. [PMID: 38387698 DOI: 10.1016/j.bpsc.2024.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 02/07/2024] [Accepted: 02/08/2024] [Indexed: 02/24/2024]
Abstract
Clinical trials of psychedelic compounds like psilocybin, lysergic acid diethylamide (LSD), and N,N-dimethyltrptamine (DMT) have forced a reconsideration of how nondrug factors, such as participant expectations, are measured and controlled in mental health research. As doses of these profoundly psychoactive substances increase, so does the difficulty in concealing the treatment condition in the classic double-blind, placebo-controlled trial design. As widespread public enthusiasm for the promise of psychedelic therapy grows, so do questions regarding whether and how much trial results are biased by positive expectancy. First, we review the key concepts related to expectancy and its measurement. Then, we review expectancy effects that have been reported in both micro- and macrodose psychedelic trials from the modern era. Finally, we consider expectancy as a discrete physiological process that can be independent of, or even interact with, the drug effect. Expectancy effects can be harnessed to improve treatment outcomes and can also be actively managed in controlled studies to enhance the rigor and generalizability of future psychedelic trials.
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Affiliation(s)
- Balázs Szigeti
- Translational Psychedelic Research Program, University of California San Francisco, San Francisco, California; Centre for Psychedelic Research, Imperial College London, London, UK
| | - Boris D Heifets
- Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, California; Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, California.
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Caliskan EB, Bingel U, Kunkel A. Translating knowledge on placebo and nocebo effects into clinical practice. Pain Rep 2024; 9:e1142. [PMID: 38533458 PMCID: PMC10965200 DOI: 10.1097/pr9.0000000000001142] [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: 04/19/2023] [Accepted: 12/18/2023] [Indexed: 03/28/2024] Open
Abstract
Introduction Positive and negative treatment expectations are powerful modulators of health and treatment outcomes. A substantial part of treatment success is due to contextual factors modulating patient's expectations towards a treatment. Consequently, treatment expectations should be a target of therapeutic interventions themselves. Objectives This article highlights the neurobiological underpinnings of treatment expectations as well as strategies to modulate contextual factors to optimize treatment outcomes in daily clinical settings. Methods This clinical update aligns with the 2022 IASP Global Year Translating Pain Knowledge into Practice and selectively reviews the best available evidence and practice. Results The effects of treatment expectations, also known as placebo and nocebo effects, are observed in various clinical conditions and physiological systems. However, most of our knowledge comes from the field of pain, where expectation effects substantially contribute to overall analgesic treatment outcomes. Experimental placebo analgesia paradigms provide the best illustration of how analgesic effects can be attributed not only to a pharmacological or specific treatment, but instead are the result of the expectation towards the treatment. The impact of expectations on treatment outcome is highly variable between individuals, and the identification of factors predicting an individual's response has proven to be challenging. Further research is required to provide personalized treatment strategies for the daily clinical practice. Conclusion Patient's previous experiences and expectations are powerful modulators of treatment efficacy, tolerability, and adherence. By providing a comprehensive overview of recent advances in this field, this review offers valuable insights for clinicians and researchers seeking to improve patient-clinician interaction.
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Affiliation(s)
- Elif Buse Caliskan
- Department of Neurology, Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Ulrike Bingel
- Department of Neurology, Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Angelika Kunkel
- Department of Neurology, Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, University of Duisburg-Essen, Essen, Germany
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7
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Kim DJ, Nascimento TD, Lim M, Danciu T, Zubieta JK, Scott PJH, Koeppe R, Kaciroti N, DaSilva AF. Exploring HD-tDCS Effect on μ-opioid Receptor and Pain Sensitivity in Temporomandibular Disorder: A Pilot Randomized Clinical Trial Study. THE JOURNAL OF PAIN 2024; 25:1070-1081. [PMID: 37956741 DOI: 10.1016/j.jpain.2023.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 10/05/2023] [Accepted: 11/01/2023] [Indexed: 11/15/2023]
Abstract
This study explored the association between experimentally-induced pain sensitivity and µ-opioid receptor (μOR) availability in patients with temporomandibular disorder (TMD) and further investigated any changes in the pain and μOR availability following high-definition transcranial direct current stimulation (HD-tDCS) over the primary motor cortex (M1) with pilot randomized clinical trials. Seven patients with TMD completed either active (n = 3) or sham treatment (n = 4) for 10 daily sessions and underwent positron emission tomography (PET) scans with [11C]carfentanil, a selective μOR agonist, a week before and after treatment. PET imaging consisted of an early resting and late phase with the sustained masseteric pain challenge by computer-controlled injection of 5% hypertonic saline. We also included 12 patients with TMD, obtained from our previous study, for baseline PET analysis. We observed that patients with more sensitivity to pain, indicated by lower infusion rate, had less μOR availability in the right amygdala during the late phase. Moreover, active M1 HD-tDCS, compared to sham, increased μOR availability post-treatment in the thalamus during the early resting phase and the amygdala, hippocampus, and parahippocampal gyrus during the late pain challenge phase. Importantly, increased μOR availability post-treatment in limbic structures including the amygdala and hippocampus was associated with decreased pain sensitivity. The findings underscore the role of the μOR system in pain regulation and the therapeutic potential of HD-tDCS for TMD. Nonetheless, large-scale studies are necessary to establish the clinical significance of these results. TRIAL REGISTRATION: ClinicalTrial.gov (NCT03724032) PERSPECTIVE: This study links pain sensitivity and µ-opioid receptors in patients with TMD. HD-tDCS over M1 improved µOR availability, which was associated with reduced pain sensitivity. Implications for TMD pain management are promising, but larger clinical trials are essential for validation.
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Affiliation(s)
- Dajung J Kim
- Headache and Orofacial Pain Effort (H.O.P.E.) Laboratory, Department of Biologic and Materials Sciences & Prosthodontics, University of Michigan School of Dentistry, Ann Arbor, Michigan; Michigan Neuroscience Institute, University of Michigan, Ann Arbor, Michigan
| | - Thiago D Nascimento
- Headache and Orofacial Pain Effort (H.O.P.E.) Laboratory, Department of Biologic and Materials Sciences & Prosthodontics, University of Michigan School of Dentistry, Ann Arbor, Michigan; Michigan Neuroscience Institute, University of Michigan, Ann Arbor, Michigan
| | - Manyoel Lim
- Food Processing Research Group, Food Convergence Research Division, Korea Food Research Institute, Jeollabuk-do, Republic of Korea
| | - Theodora Danciu
- Department of Periodontics & Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, Michigan
| | - Jon-Kar Zubieta
- Department of Psychiatry, Mass General Brigham, Newton-Wellesley Hospital, Newton, Massachusetts
| | - Peter J H Scott
- Department of Radiology, University of Michigan, Ann Arbor, Michigan
| | - Robert Koeppe
- Department of Radiology, University of Michigan, Ann Arbor, Michigan
| | - Niko Kaciroti
- Department of Biostatistics, University of Michigan, Ann Arbor, Michigan
| | - Alexandre F DaSilva
- Headache and Orofacial Pain Effort (H.O.P.E.) Laboratory, Department of Biologic and Materials Sciences & Prosthodontics, University of Michigan School of Dentistry, Ann Arbor, Michigan; Michigan Neuroscience Institute, University of Michigan, Ann Arbor, Michigan
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8
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Totsch SK, Sorge RE. A novel investigation of placebo analgesia through social communication in mice. Behav Brain Res 2024; 459:114773. [PMID: 38000532 DOI: 10.1016/j.bbr.2023.114773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/08/2023] [Accepted: 11/20/2023] [Indexed: 11/26/2023]
Abstract
BACKGROUND AND AIMS In rodents, placebo analgesia is often investigated through direct conditioning of stimuli, but humans can experience placebo analgesia through expectation without experience. In this study, we sought to determine whether placebo analgesia could be elicited through social communication. METHODS Male and female mice were housed in pairs (designated "Active" and "Bystander") and tested for thermal thresholds on a hot plate (53 °C). Food restriction (1 hr/day) was implemented. The Active mouse was taken to a new cage with food dusted with cocoa (COC) or cinnamon (CINN). The Bystander mice were given regular chow in the home cage. After feeding, the Active mice were given morphine (5 mg/kg, SC) or saline and tested on the hot plate. After 5 pairings of a flavor and treatment (counterbalanced), Active mice were tested following access to a flavored food. Bystander mice were given their first direct exposure to a flavored food and tested on the hot plate. The protocol was repeated with naloxone (10 mg/kg, IP) administered prior to testing. Finally, mice were tested in a two-choice test with both flavored foods available. RESULTS Active mice showed a conditioned analgesic response to the morphine-paired flavor that was reduced by naloxone. Bystander mice showed a placebo analgesic response to their cagemate's morphine-paired flavor that was not significantly impacted by naloxone. Bystander mice spent more time in the chamber associated with their cagemate's morphine-paired flavor. CONCLUSIONS To our knowledge, this is the first investigation of placebo analgesia without direct conditioning, instead relying on social communication between mice. The lack of effect with naloxone pretreatment suggests an opioid-independent effect in the Bystander mice. Placebo analgesia in mice may be possible without direct conditioning to better model the effect of expectation of a novel analgesic in humans.
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Affiliation(s)
- Stacie K Totsch
- Department of Psychology, University of Alabama at Birmingham, United States
| | - Robert E Sorge
- Department of Psychology, University of Alabama at Birmingham, United States.
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9
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Murray BP, Kiernan EA. Physiologic Effects of Substance Use. Emerg Med Clin North Am 2024; 42:69-91. [PMID: 37977754 DOI: 10.1016/j.emc.2023.06.022] [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] [Indexed: 11/19/2023]
Abstract
Physiologic and psychological effects of substance use are common occurrences. They may be the proximate purpose of the exposure or related to an unintended complication. Acute short-term exposure effects may not be the same as long-term effects. These effects are mediated by different receptors they act on and the homeostatic changes that occur due to repeat exposure. We review in this article the physiologic and psychological effects from exposure to commonly encountered drugs, ethanol, sedative hypnotics, cocaine, amphetamines, marijuana, opioids, nicotine, hydrocarbons (halogenated and non-halogenated), and nitrous oxide.
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Affiliation(s)
- Brian Patrick Murray
- Department of Emergency Medicine, Wright State Boonshoft School of Medicine, 2555 University Boulevard, Suite 110, Dayton, OH 45324, USA.
| | - Emily Anne Kiernan
- Department of Emergency Medicine, Emory University School of Medicine, 50 Hurtz Plaza Southeast, Suite 600, Atlanta, GA, USA; Georgia Poison Center, 50 Hurtz Plaza Southeast, Suite 600, Atlanta, GA, USA
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10
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Di Ianni T, Ewbank SN, Levinstein MR, Azadian MM, Budinich RC, Michaelides M, Airan RD. Sex dependence of opioid-mediated responses to subanesthetic ketamine in rats. Nat Commun 2024; 15:893. [PMID: 38291050 PMCID: PMC10828511 DOI: 10.1038/s41467-024-45157-7] [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: 04/23/2023] [Accepted: 01/17/2024] [Indexed: 02/01/2024] Open
Abstract
Subanesthetic ketamine is increasingly used for the treatment of varied psychiatric conditions, both on- and off-label. While it is commonly classified as an N-methyl D-aspartate receptor (NMDAR) antagonist, our picture of ketamine's mechanistic underpinnings is incomplete. Recent clinical evidence has indicated, controversially, that a component of the efficacy of subanesthetic ketamine may be opioid dependent. Using pharmacological functional ultrasound imaging in rats, we found that blocking opioid receptors suppressed neurophysiologic changes evoked by ketamine, but not by a more selective NMDAR antagonist, in limbic regions implicated in the pathophysiology of depression and in reward processing. Importantly, this opioid-dependent response was strongly sex-dependent, as it was not evident in female subjects and was fully reversed by surgical removal of the male gonads. We observed similar sex-dependent effects of opioid blockade affecting ketamine-evoked postsynaptic density and behavioral sensitization, as well as in opioid blockade-induced changes in opioid receptor density. Together, these results underscore the potential for ketamine to induce its affective responses via opioid signaling, and indicate that this opioid dependence may be strongly influenced by subject sex. These factors should be more directly assessed in future clinical trials.
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Affiliation(s)
- Tommaso Di Ianni
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
- Departments of Psychiatry & Behavioral Sciences and Radiology & Biomedical Imaging, University of California, San Francisco, San Francisco, CA, 94143, USA.
| | - Sedona N Ewbank
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Marjorie R Levinstein
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, 21224, USA
| | - Matine M Azadian
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Reece C Budinich
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, 21224, USA
| | - Michael Michaelides
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, 21224, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Raag D Airan
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
- Department of Materials Science and Engineering, Stanford University School of Medicine, Stanford, CA, 94305, USA.
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, 94305, USA.
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11
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Yao D, Chen Y, Chen G. The role of pain modulation pathway and related brain regions in pain. Rev Neurosci 2023; 34:899-914. [PMID: 37288945 DOI: 10.1515/revneuro-2023-0037] [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: 03/25/2023] [Accepted: 05/18/2023] [Indexed: 06/09/2023]
Abstract
Pain is a multifaceted process that encompasses unpleasant sensory and emotional experiences. The essence of the pain process is aversion, or perceived negative emotion. Central sensitization plays a significant role in initiating and perpetuating of chronic pain. Melzack proposed the concept of the "pain matrix", in which brain regions associated with pain form an interconnected network, rather than being controlled by a singular brain region. This review aims to investigate distinct brain regions involved in pain and their interconnections. In addition, it also sheds light on the reciprocal connectivity between the ascending and descending pathways that participate in pain modulation. We review the involvement of various brain areas during pain and focus on understanding the connections among them, which can contribute to a better understanding of pain mechanisms and provide opportunities for further research on therapies for improved pain management.
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Affiliation(s)
- Dandan Yao
- Department of Anesthesiology, School of Medicine, Shaoxing University, Shaoxing, Zhejiang, China
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Yeru Chen
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Gang Chen
- Department of Anesthesiology, School of Medicine, Shaoxing University, Shaoxing, Zhejiang, China
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China
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12
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Basedau H, Ornello R, Matteis ED, Davaasuren B, Kadyrova B, Vuralli D, Bozhenko M, Azizova I, Bitsadze N, Eralieva E, Ashina M, Mitsikostas D, Puledda F. Placebo and nocebo in the treatment of migraine: How much does real world effectiveness depend on contextual effects? Cephalalgia 2023; 43:3331024231218392. [PMID: 38041833 DOI: 10.1177/03331024231218392] [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] [Indexed: 12/04/2023]
Abstract
PURPOSE Treatments in medicine impact individuals beyond their intended effects, due to phenomena such as the placebo and nocebo effects. The placebo effect arises from the positive expectation of a treatment being beneficial, while the nocebo effect stems from the negative expectation of a treatment causing harm. Both in real-world practice and clinical trials, treatments can lead to outcomes unrelated to their intended mechanism of action, which we categorize as placebo and nocebo responses. These responses, combined with the inherent fluctuation in a condition's natural progression, regression to the mean, and random comorbidities, make up a significant part of the therapeutic experience. Particularly in pain management, placebo and nocebo effects play a substantial role. By addressing modifiable contextual factors such as patient expectations, lifestyle choices, and the therapeutic relationship, healthcare providers can enhance the effectiveness of migraine treatments, paving the way for a more comprehensive, individualized approach to patient care. We must also consider non-modifiable factors like personal experiences, beliefs, and information from social media and the internet. CONCLUSION This review offers a summary of our current understanding of the placebo and nocebo effects in migraine management.
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Affiliation(s)
- Hauke Basedau
- Department of Systems Neuroscience, University Medical Center Hamburg- Eppendorf, Hamburg, Germany
| | - Raffaele Ornello
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy
| | - Eleonora De Matteis
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy
| | | | - Begimai Kadyrova
- Department of Special Clinical Disciplines, International School of Medicine of International University of Kyrgyzstan, Bishkek, Kyrgyzstan
| | - Doga Vuralli
- Department of Neurology and Algology, Neuropsychiatry Center, Neuroscience and Neurotechnology Center of Excellence (NÖROM), Gazi University, Ankara, Turkey
| | - Myroslav Bozhenko
- Department of Neurology, Danylo Halytsky Lviv National Medical University, Lviv, Ukraine
| | - Ilaha Azizova
- Neurological Clinic "New Medical Technologies", Baku, Azerbaijan
| | | | | | - Messoud Ashina
- Danish Headache Center, Department of Neurology, Rigshospitalet-Glostrup, University of Copenhagen, Copenhagen, Denmark
| | - Dimos Mitsikostas
- Department of Neurology Α, Aegintion Hospital, National and Kapidistrian University of Athens, Athens, Greece
| | - Francesca Puledda
- Headache Group, Wolfson SPaRC, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
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Abstract
BACKGROUND AND HYPOTHESIS The neurocomputational framework of predictive processing (PP) provides a promising approach to explaining delusions, a key symptom of psychotic disorders. According to PP, the brain makes inferences about the world by weighing prior beliefs against the available sensory data. Mismatches between prior beliefs and sensory data result in prediction errors that may update the brain's model of the world. Psychosis has been associated with reduced weighting of priors relative to the sensory data. However, delusional beliefs are highly resistant to change, suggesting increased rather than decreased weighting of priors. We propose that this "delusion paradox" can be resolved within a hierarchical PP model: Reduced weighting of prior beliefs at low hierarchical levels may be compensated by an increased influence of higher-order beliefs represented at high hierarchical levels, including delusional beliefs. This may sculpt perceptual processing into conformity with delusions and foster their resistance to contradictory evidence. STUDY DESIGN We review several lines of experimental evidence on low- and high-level processes, and their neurocognitive underpinnings in delusion-related phenotypes and link them to predicted processing. STUDY RESULTS The reviewed evidence supports the notion of decreased weighting of low-level priors and increased weighting of high-level priors, in both delusional and delusion-prone individuals. Moreover, we highlight the role of prefrontal cortex as a neural basis for the increased weighting of high-level prior beliefs and discuss possible clinical implications of the proposed hierarchical predictive-processing model. CONCLUSIONS Our review suggests the delusion paradox can be resolved within a hierarchical PP model.
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Affiliation(s)
- Predrag Petrovic
- Center for Psychiatry Research (CPF), Center for Cognitive and Computational Neuropsychiatry (CCNP), Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Philipp Sterzer
- Department of Psychiatry (UPK), University of Basel, Basel, Switzerland
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Kotikalapudi R, Kincses B, Zunhammer M, Schlitt F, Asan L, Schmidt-Wilcke T, Kincses ZT, Bingel U, Spisak T. Brain morphology predicts individual sensitivity to pain: a multicenter machine learning approach. Pain 2023; 164:2516-2527. [PMID: 37318027 PMCID: PMC10578427 DOI: 10.1097/j.pain.0000000000002958] [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: 08/19/2022] [Revised: 02/18/2023] [Accepted: 03/23/2023] [Indexed: 06/16/2023]
Abstract
ABSTRACT Sensitivity to pain shows a remarkable interindividual variance that has been reported to both forecast and accompany various clinical pain conditions. Although pain thresholds have been reported to be associated to brain morphology, it is still unclear how well these findings replicate in independent data and whether they are powerful enough to provide reliable pain sensitivity predictions on the individual level. In this study, we constructed a predictive model of pain sensitivity (as measured with pain thresholds) using structural magnetic resonance imaging-based cortical thickness data from a multicentre data set (3 centres and 131 healthy participants). Cross-validated estimates revealed a statistically significant and clinically relevant predictive performance (Pearson r = 0.36, P < 0.0002, R2 = 0.13). The predictions were found to be specific to physical pain thresholds and not biased towards potential confounding effects (eg, anxiety, stress, depression, centre effects, and pain self-evaluation). Analysis of model coefficients suggests that the most robust cortical thickness predictors of pain sensitivity are the right rostral anterior cingulate gyrus, left parahippocampal gyrus, and left temporal pole. Cortical thickness in these regions was negatively correlated to pain sensitivity. Our results can be considered as a proof-of-concept for the capacity of brain morphology to predict pain sensitivity, paving the way towards future multimodal brain-based biomarkers of pain.
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Affiliation(s)
- Raviteja Kotikalapudi
- Institute for Diagnostic and Interventional Radiology and Neuroradiology, University Medicine Essen, Essen, Germany
| | - Balint Kincses
- Institute for Diagnostic and Interventional Radiology and Neuroradiology, University Medicine Essen, Essen, Germany
- Department of Neurology, Center for Translational Neuro- and Behavioural Sciences, University Medicine Essen, Essen, Germany
| | - Matthias Zunhammer
- Department of Neurology, Center for Translational Neuro- and Behavioural Sciences, University Medicine Essen, Essen, Germany
| | - Frederik Schlitt
- Department of Neurology, Center for Translational Neuro- and Behavioural Sciences, University Medicine Essen, Essen, Germany
| | - Livia Asan
- Department of Neurology, Center for Translational Neuro- and Behavioural Sciences, University Medicine Essen, Essen, Germany
| | - Tobias Schmidt-Wilcke
- Institute for Clinical Neuroscience and Medical Psychology, Heinrich Heine University, Düsseldorf, Germany
- Neurocenter, District Hospital Mainkofen, Deggendorf, Germany
| | - Zsigmond T. Kincses
- Departments of Neurology and
- Radiology, University of Szeged, Szeged, Hungary
| | - Ulrike Bingel
- Department of Neurology, Center for Translational Neuro- and Behavioural Sciences, University Medicine Essen, Essen, Germany
| | - Tamas Spisak
- Institute for Diagnostic and Interventional Radiology and Neuroradiology, University Medicine Essen, Essen, Germany
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Ochandarena NE, Niehaus JK, Tassou A, Scherrer G. Cell-type specific molecular architecture for mu opioid receptor function in pain and addiction circuits. Neuropharmacology 2023; 238:109597. [PMID: 37271281 PMCID: PMC10494323 DOI: 10.1016/j.neuropharm.2023.109597] [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: 04/12/2023] [Accepted: 05/13/2023] [Indexed: 06/06/2023]
Abstract
Opioids are potent analgesics broadly used for pain management; however, they can produce dangerous side effects including addiction and respiratory depression. These harmful effects have led to an epidemic of opioid abuse and overdose deaths, creating an urgent need for the development of both safer pain medications and treatments for opioid use disorders. Both the analgesic and addictive properties of opioids are mediated by the mu opioid receptor (MOR), making resolution of the cell types and neural circuits responsible for each of the effects of opioids a critical research goal. Single-cell RNA sequencing (scRNA-seq) technology is enabling the identification of MOR-expressing cell types throughout the nervous system, creating new opportunities for mapping distinct opioid effects onto newly discovered cell types. Here, we describe molecularly defined MOR-expressing neuronal cell types throughout the peripheral and central nervous systems and their potential contributions to opioid analgesia and addiction.
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Affiliation(s)
- Nicole E Ochandarena
- Neuroscience Curriculum, Biological and Biomedical Sciences Program, The University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA; Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA; UNC Neuroscience Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA; Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
| | - Jesse K Niehaus
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA; UNC Neuroscience Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA; Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Adrien Tassou
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA; UNC Neuroscience Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA; Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Grégory Scherrer
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA; UNC Neuroscience Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA; Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA; New York Stem Cell Foundation - Robertson Investigator, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
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Choe S, Kim YK, Chung W, Ko D, Lee M, Shim SR, Ha A. Placebo Effect and Its Determinants in Ocular Hypotensive Therapy: Meta-analysis and Multiple Meta-regression Analysis. Ophthalmology 2023; 130:1149-1161. [PMID: 37343706 DOI: 10.1016/j.ophtha.2023.06.012] [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: 03/01/2023] [Revised: 05/18/2023] [Accepted: 06/13/2023] [Indexed: 06/23/2023] Open
Abstract
TOPIC The placebo effect and its potential determinants in ocular hypotensive therapy. CLINICAL RELEVANCE The placebo effect has been studied and documented within a wide clinical context. It remains unclear whether placebo is effective in glaucoma treatment or, if so, which factors are determinative of effect size (ES). METHODS Randomized controlled trials (RCTs) of topical ocular hypotensive therapy for patients with open-angle glaucoma or ocular hypertension, conducted through June 2, 2022, were included. First, a perceived placebo effect was measured as the overall intraocular pressure (IOP) change from the baseline. It was evaluated in terms of the ES (mean difference between the baseline and the end point) and then was compared with the ES, as obtained from the untreated control participant to obtain a true placebo effect. The primary outcome was ES based on 4 weeks of treatment. Meta-analysis-based statistical pooling was performed where appropriate, and 95% confidence intervals (CIs) were used for comparison. Potential placebo effect determinants were scrutinized using a multiple meta-regression model (PROSPERO identifier, CRD42022348098). RESULTS A total of 40 RCTs (7829 eyes) with 33 placebo groups (2055 eyes) along with 7 untreated groups (1184 eyes) were included. Among placebo-controlled trials, placebo was determined to be effective in lowering IOP (ES, -1.30 mmHg; 95% CI, -1.75 to -0.84 mmHg). Using NMA, the ES for placebo was -2.27 mmHg (95% CI, -3.52 to -1.01 mmHg) greater than ES for untreated control participants.. According to the multiple meta-regression model, the active treatment ES was a significant factor to predict the amount of placebo effect. Placebo additionally lowered IOP by -0.45 mmHg per -1 mmHg of active treatment effect. Add-on study design and larger sample size also were associated with greater amount of placebo effect. No publication bias was evident in either a funnel plot or the Begg and Mazumdar adjusted rank correlation test results (P = 0.24). DISCUSSION This meta-analysis indicated that placebo is effective in lowering IOP and is superior to the effect observed for the untreated control participants. However, caution is required in interpreting the results because of the small number of untreated controlled trials and potential bias from the lack of direct comparison between the placebo and untreated arms. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.
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Affiliation(s)
- Sooyeon Choe
- Department of Ophthalmology, Chungnam National University Hospital, Daejeon, Republic of Korea; Department of Ophthalmology, Chungnam National University, Daejeon, Republic of Korea
| | - Young Kook Kim
- Department of Ophthalmology, Seoul National University Hospital, Seoul, Republic of Korea; Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Republic of Korea; EyeLight Data Science Laboratory, Seoul National University College of Medicine, Seoul, Republic of Korea.
| | - Woosuk Chung
- Department of Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Donghyun Ko
- Department of Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Marvin Lee
- Allbarun Eye Clinic, Suwon-si, Republic of Korea
| | - Sung Ryul Shim
- Department of Health and Medical Informatics, Kyungnam University College of Health Sciences, Changwon, Republic of Korea
| | - Ahnul Ha
- Department of Ophthalmology, Jeju National University Hospital, Jeju-si, Republic of Korea; Department of Ophthalmology, Jeju National University School of Medicine, Jeju-si, Republic of Korea.
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Liu T, Yu CP. How Do Expectations Modulate Pain? A Motivational Perspective. PERSPECTIVES ON PSYCHOLOGICAL SCIENCE 2023; 18:1508-1519. [PMID: 37369088 DOI: 10.1177/17456916231178701] [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] [Indexed: 06/29/2023]
Abstract
Expectations can profoundly modulate pain experience, during which the periaqueductal gray (PAG) plays a pivotal role. In this article, we focus on motivationally evoked neural activations in cortical and brainstem regions both before and during stimulus administration, as has been demonstrated by experimental studies on pain-modulatory effects of expectations, in the hope of unraveling how the PAG is involved in descending and ascending nociceptive processes. This motivational perspective on expectancy effects on the perception of noxious stimuli sheds new light on psychological and neuronal substrates of pain and its modulation, thus having important research and clinical implications.
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Affiliation(s)
- Tao Liu
- The Second Teaching Hospital, University of Jilin
| | - Cui-Ping Yu
- Department of Basic Medicine, Changchun Medical College
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18
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Nguyen E, Chiang MC, Nguyen C, Ross SE. Brainstem Modulation of Nociception by Periaqueductal Gray Neurons Expressing the μ-Opioid Receptor in Mice. Anesthesiology 2023; 139:462-475. [PMID: 37364291 PMCID: PMC10870981 DOI: 10.1097/aln.0000000000004668] [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] [Indexed: 06/28/2023]
Abstract
BACKGROUND Pharmacologic manipulations directed at the periaqueductal gray have demonstrated the importance of the μ-opioid receptor in modulating reflexive responses to nociception. The authors hypothesized that a supraspinal pathway centered on neurons in the periaqueductal gray containing the μ-opioid receptor could modulate nociceptive and itch behaviors. METHODS The study used anatomical, optogenetic, and chemogenetic approaches in male and female mice to manipulate μ-opioid receptor neurons in the periaqueductal gray. Behavioral assays including von Frey, Hargreaves, cold plantar, chloroquine-induced itch, hotplate, formalin-induced injury, capsaicin-induced injury, and open field tests were used. In separate experiments, naloxone was administered in a postsurgical model of latent sensitization. RESULTS Activation of μ-opioid receptor neurons in the periaqueductal gray increased jumping (least-squares mean difference of -3.30 s; 95% CI, -6.17 to -0.44; P = 0.023; n = 7 or 8 mice per group), reduced itch responses (least-squares mean difference of 70 scratching bouts; 95% CI, 35 to 105; P < 0.001; n = 8 mice), and elicited modestly antinociceptive effects (least-squares mean difference of -0.7 g on mechanical and -10.24 s on thermal testing; 95% CI, -1.3 to -0.2 and 95% CI, -13.77 to -6.70, and P = 0.005 and P < 0.001, respectively; n = 8 mice). Last, the study uncovered the role of the periaqueductal gray in suppressing hyperalgesia after a postsurgical state of latent sensitization (least-squares mean difference comparing saline and naloxone of -12 jumps; 95% CI, -17 to -7; P < 0.001 for controls; and -2 jumps; 95% CI, -7 to 4; P = 0.706 after optogenetic stimulation; n = 7 to 9 mice per group). CONCLUSIONS μ-Opioid receptor neurons in the periaqueductal gray modulate distinct nocifensive behaviors: their activation reduced responses to mechanical and thermal testing, and attenuated scratching behaviors, but facilitated escape responses. The findings emphasize the role of the periaqueductal gray in the behavioral expression of nociception using reflexive and noxious paradigms. EDITOR’S PERSPECTIVE
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Affiliation(s)
- Eileen Nguyen
- University of Pittsburgh School of Medicine, Department of Anesthesiology, Pittsburgh, PA, USA
- University of Pittsburgh, Department of Neurobiology, Pittsburgh, PA, USA
- University of California, Los Angeles, Department of Anesthesiology, Los Angeles, CA, USA
| | - Michael C. Chiang
- University of Pittsburgh School of Medicine, Department of Anesthesiology, Pittsburgh, PA, USA
- University of Pittsburgh, Department of Neurobiology, Pittsburgh, PA, USA
| | - Catherine Nguyen
- University of Pittsburgh School of Medicine, Department of Anesthesiology, Pittsburgh, PA, USA
- University of Pittsburgh, Department of Neurobiology, Pittsburgh, PA, USA
| | - Sarah E. Ross
- University of Pittsburgh School of Medicine, Department of Anesthesiology, Pittsburgh, PA, USA
- University of Pittsburgh, Department of Neurobiology, Pittsburgh, PA, USA
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Botvinik-Nezer R, Petre B, Ceko M, Lindquist MA, Friedman NP, Wager TD. Placebo treatment affects brain systems related to affective and cognitive processes, but not nociceptive pain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.21.558825. [PMID: 37790543 PMCID: PMC10543005 DOI: 10.1101/2023.09.21.558825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Placebo analgesia is a replicable and well-studied phenomenon, yet it remains unclear to what degree it includes modulation of nociceptive processes. Some studies find effects consistent with nociceptive effects, but meta-analyses show that these effects are often small. We analyzed placebo analgesia in a large fMRI study (N = 392), including placebo effects on brain responses to noxious stimuli. Placebo treatment caused robust analgesia in both conditioned thermal and unconditioned mechanical pain. Placebo did not decrease fMRI activity in nociceptive pain regions, including the Neurologic Pain Signature (NPS) and pre-registered spinothalamic pathway regions, with strong support from Bayes Factor analyses. However, placebo treatment affected activity in pre-registered analyses of a second neuromarker, the Stimulus Intensity Independent Pain Signature (SIIPS), and several associated a priori brain regions related to motivation and value, in both thermal and mechanical pain. Individual differences in behavioral analgesia were correlated with neural changes in both thermal and mechanical pain. Our results indicate that processes related to affective and cognitive aspects of pain primarily drive placebo analgesia.
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20
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Krecké J, Dierolf AM, Rischer KM, Anton F, van der Meulen M. Baseline heart rate variability predicts placebo hypoalgesia in men, but not women. FRONTIERS IN PAIN RESEARCH 2023; 4:1213848. [PMID: 37799824 PMCID: PMC10547887 DOI: 10.3389/fpain.2023.1213848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/31/2023] [Indexed: 10/07/2023] Open
Abstract
Introduction Placebo hypoalgesic effects vary greatly across individuals, making them challenging to control for in clinical trials and difficult to use in treatment. We investigated the potential of resting vagally-mediated heart rate variability (vmHRV) to help predict the magnitude of placebo responsiveness. Methods In two independent studies (total N = 77), we administered a placebo paradigm after measuring baseline HRV. In Study I, we delivered heat pain to the forearm, on skin patches treated with "real" and "control" cream (identical inactive creams). In Study II, electrical pulses to the forearm were modulated by sham transcutaneous electrical nerve stimulation. We combined data from both studies to evaluate the relationship between vagally-mediated HRV (vmHRV) parameters and the placebo response size, while also assessing sex differences in this relationship. Results and Discussion This revealed a positive association between vmHRV and the degree of pain relief, and this effect was driven by men. These results not only reveal new insights into the (sex-specific) mechanisms of placebo hypoalgesia, but also suggest that measuring vmHRV may be helpful in predicting placebo responsiveness. Given that placebo hypoalgesic effects contribute substantially to treatment outcomes, such a non-invasive and easily obtained predictor would be valuable in the context of personalized medicine.
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Affiliation(s)
- Joy Krecké
- Department of Behavioural and Cognitive Sciences, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | | | | | | | - Marian van der Meulen
- Department of Behavioural and Cognitive Sciences, University of Luxembourg, Esch-sur-Alzette, Luxembourg
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Crawford LS, Mills EP, Peek A, Macefield VG, Keay KA, Henderson LA. Function and biochemistry of the dorsolateral prefrontal cortex during placebo analgesia: how the certainty of prior experiences shapes endogenous pain relief. Cereb Cortex 2023; 33:9822-9834. [PMID: 37415068 PMCID: PMC10472490 DOI: 10.1093/cercor/bhad247] [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: 04/05/2023] [Revised: 06/15/2023] [Accepted: 06/17/2023] [Indexed: 07/08/2023] Open
Abstract
Prior experiences, conditioning cues, and expectations of improvement are essential for placebo analgesia expression. The dorsolateral prefrontal cortex is considered a key region for converting these factors into placebo responses. Since dorsolateral prefrontal cortex neuromodulation can attenuate or amplify placebo, we sought to investigate dorsolateral prefrontal cortex biochemistry and function in 38 healthy individuals during placebo analgesia. After conditioning participants to expect pain relief from a placebo "lidocaine" cream, we collected baseline magnetic resonance spectroscopy (1H-MRS) at 7 Tesla over the right dorsolateral prefrontal cortex. Following this, functional magnetic resonance imaging scans were collected during which identical noxious heat stimuli were delivered to the control and placebo-treated forearm sites. There was no significant difference in the concentration of gamma-aminobutyric acid, glutamate, Myo-inositol, or N-acetylaspartate at the level of the right dorsolateral prefrontal cortex between placebo responders and nonresponders. However, we identified a significant inverse relationship between the excitatory neurotransmitter glutamate and pain rating variability during conditioning. Moreover, we found placebo-related activation within the right dorsolateral prefrontal cortex and altered functional magnetic resonance imaging coupling between the dorsolateral prefrontal cortex and the midbrain periaqueductal gray, which also correlated with dorsolateral prefrontal cortex glutamate. These data suggest that the dorsolateral prefrontal cortex formulates stimulus-response relationships during conditioning, which are then translated to altered cortico-brainstem functional relationships and placebo analgesia expression.
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Affiliation(s)
- Lewis S Crawford
- School of Medical Sciences (Neuroscience), Brain and Mind Centre, University of Sydney, Sydney 2006, Australia
| | - Emily P Mills
- School of Medical Sciences (Neuroscience), Brain and Mind Centre, University of Sydney, Sydney 2006, Australia
| | - A Peek
- School of Medical Sciences (Neuroscience), Brain and Mind Centre, University of Sydney, Sydney 2006, Australia
| | | | - Kevin A Keay
- School of Medical Sciences (Neuroscience), Brain and Mind Centre, University of Sydney, Sydney 2006, Australia
| | - Luke A Henderson
- School of Medical Sciences (Neuroscience), Brain and Mind Centre, University of Sydney, Sydney 2006, Australia
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22
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Papassidero P, Wichert-Ana L, Lia EN, Alexandre-Santos L, Trevisan AC, Coelho EB, Della Pasqua O, Lanchote VL, Dach F. Pharmacodynamic effect of gabapentin on central nervous system in patients with chronic low back pain: a [99mTc]Tc-ECD SPECT study. Reg Anesth Pain Med 2023; 48:408-413. [PMID: 37001886 DOI: 10.1136/rapm-2022-104047] [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: 09/23/2022] [Accepted: 02/19/2023] [Indexed: 04/03/2023]
Abstract
BACKGROUND Gabapentin is an effective therapeutic alternative for chronic low back pain, indicated in several guidelines for treating neuropathic pain as first-line medication. This study aimed to describe the pharmacodynamics of gabapentin in the central nervous system of patients with chronic low back pain (CLBP) by using single-photon emission CT (SPECT) with [99mTc]Tc-ECD. METHODS We selected 13 patients with CLBP due to lumbar disc herniation. They underwent SPECT before and after using gabapentin, compared with a SPECT database of healthy volunteers. A second analysis compared regional cerebral blood flow (rCBF) changes between responders and non-responders to gabapentin and the healthy controls. RESULTS The mean age of patients was 41 years, and the mean pain intensity was 5.92 points, measured by the Numeric Rating Scale. After using gabapentin, SPECT showed an increase of rCBF in the bilateral anterior cingulate gyrus and a decrease of rCBF in periaqueductal gray matter. Non-responder patients with gabapentin showed a post-treatment decrease of rCBF in the paracentral lobule of the brain. CONCLUSIONS A lack of improvement in some patients with gabapentin may be associated with an activated affective circuit of pain, evidenced by the increase of rCBF of the anterior cingulate cortex. A maladaptive brain state in chronic pain can explain the decrease of rCBF in the default mode network structures. Gabapentin acts directly or indirectly on neurons of periaqueductal gray substance by increasing the pain threshold and decreasing the rCBF of this structure.
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Affiliation(s)
- Priscila Papassidero
- Department of Neurosciences and Behavioral Sciences, USP Ribeirao Preto, Ribeirao Preto, Brazil
| | - Lauro Wichert-Ana
- Nuclear Medicine and PET/CT Laboratory, Department of Medical Imaging, Hematology and Clinical Oncology, USP Ribeirao Preto, Ribeirao Preto, Brazil
| | - Erica Negrini Lia
- Department of Dentistry, School of Health Sciences, University of Brasilia, Brasilia, Brazil
| | - Leonardo Alexandre-Santos
- Nuclear Medicine and PET/CT Laboratory, Department of Medical Imaging, Hematology and Clinical Oncology, USP Ribeirao Preto, Ribeirao Preto, Brazil
| | - Ana Carolina Trevisan
- Nuclear Medicine and PET/CT Laboratory, Department of Medical Imaging, Hematology and Clinical Oncology, USP Ribeirao Preto, Ribeirao Preto, Brazil
| | | | - Oscar Della Pasqua
- Department of Pharmacology, UCL School of Pharmacy, London, UK
- Clinical Pharmacology Modelling & Simulation, GlaxoSmithKline Plc, London, UK
| | - Vera Lúcia Lanchote
- Department of Clinical Analysis, Food Science and Toxicology, USP Ribeirao Preto, Ribeirao Preto, Brazil
| | - Fabíola Dach
- Department of Neurosciences and Behavioral Sciences, USP Ribeirao Preto, Ribeirao Preto, Brazil
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Vanneste S, De Ridder D. BurstDR spinal cord stimulation rebalances pain input and pain suppression in the brain in chronic neuropathic pain. Brain Stimul 2023; 16:1186-1195. [PMID: 37541579 DOI: 10.1016/j.brs.2023.07.058] [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: 01/26/2023] [Revised: 07/06/2023] [Accepted: 07/31/2023] [Indexed: 08/06/2023] Open
Abstract
OBJECTIVE Chronic pain is processed by at least three well-known pathways, two pain provoking pathways including a medial 'suffering' and lateral 'painfulness' pathway. A third descending pain pathway modulates pain but is predominantly inhibitory. Chronic pain can be seen as an imbalance between the two pain-provoking and the pain inhibitory pathways. If this assumption is correct, then the imbalance between pain input and pain suppression should reverse and normalize in response to successful, i.e., pain reducing burstDR spinal cord stimulation, one of the current treatment options for neuropathic pain. MATERIALS AND METHODS Fifteen patients, who received spinal cord stimulation for failed back surgery were included in this study, using source localized electrical brain activity and connectivity recording via EEG to identify the purported imbalance. RESULTS BurstDR spinal cord stimulation induces a significant change in EEG activity in both the left and right somatosensory cortex (SSC) for both θ and γ oscillations. In the dorsal anterior cingulate cortex (dACC), we observed a significant drop in both α and β oscillations. This reduction is accompanied by a change in pain intensity and suffering. BurstDR spinal cord stimulation is also associated with a reduction in θ at the pregenual anterior cingulate cortex (pgACC). Analyzing effective connectivity indicates that for the θ band, more information is sent from the pgACC to the left and right SSC. For α, increased information is sent from the pgACC to the dACC and both the left and right SSC. This is associated with a reduced θ-γ coupling in the SSC and reduced α-β coupling in dACC. CONCLUSION This study suggests that chronic pain is indeed an imbalance between the ascending and descending pathways in the brain and that burst spinal cord stimulation can normalize this imbalance in the brain.
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Affiliation(s)
- Sven Vanneste
- Global Brain Health Institute, Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland.
| | - Dirk De Ridder
- Department of Surgical Sciences, Section of Neurosurgery, Dunedin School of Medicine, University of Otago, New Zealand
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24
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Rossettini G, Campaci F, Bialosky J, Huysmans E, Vase L, Carlino E. The Biology of Placebo and Nocebo Effects on Experimental and Chronic Pain: State of the Art. J Clin Med 2023; 12:4113. [PMID: 37373806 DOI: 10.3390/jcm12124113] [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: 05/22/2023] [Revised: 06/13/2023] [Accepted: 06/15/2023] [Indexed: 06/29/2023] Open
Abstract
(1) Background: In recent years, placebo and nocebo effects have been extensively documented in different medical conditions, including pain. The scientific literature has provided strong evidence of how the psychosocial context accompanying the treatment administration can influence the therapeutic outcome positively (placebo effects) or negatively (nocebo effects). (2) Methods: This state-of-the-art paper aims to provide an updated overview of placebo and nocebo effects on pain. (3) Results: The most common study designs, the psychological mechanisms, and neurobiological/genetic determinants of these phenomena are discussed, focusing on the differences between positive and negative context effects on pain in experimental settings on healthy volunteers and in clinical settings on chronic pain patients. Finally, the last section describes the implications for clinical and research practice to maximize the medical and scientific routine and correctly interpret the results of research studies on placebo and nocebo effects. (4) Conclusions: While studies on healthy participants seem consistent and provide a clear picture of how the brain reacts to the context, there are no unique results of the occurrence and magnitude of placebo and nocebo effects in chronic pain patients, mainly due to the heterogeneity of pain. This opens up the need for future studies on the topic.
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Affiliation(s)
| | - Francesco Campaci
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, 10124 Turin, Italy
| | - Joel Bialosky
- Department of Physical Therapy, University of Florida, Gainesville, FL 32611, USA
- Clinical Research Center, Brooks Rehabilitation, Jacksonville, FL 32211, USA
| | - Eva Huysmans
- Pain in Motion Research Group (PAIN), Department of Physiotherapy, Human Physiology and Anatomy, Faculty of Physical Education & Physiotherapy, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium
- Department of Physical Medicine and Physiotherapy, Universitair Ziekenhuis Brussel, Laarbeeklaan 101, 1090 Brussels, Belgium
| | - Lene Vase
- Department of Psychology and Behavioural Sciences, School of Business and Social Sciences, Aarhus University, 8000 Aarhus, Denmark
| | - Elisa Carlino
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, 10124 Turin, Italy
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25
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Motzkin JC, Kanungo I, D’Esposito M, Shirvalkar P. Network targets for therapeutic brain stimulation: towards personalized therapy for pain. FRONTIERS IN PAIN RESEARCH 2023; 4:1156108. [PMID: 37363755 PMCID: PMC10286871 DOI: 10.3389/fpain.2023.1156108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 05/19/2023] [Indexed: 06/28/2023] Open
Abstract
Precision neuromodulation of central brain circuits is a promising emerging therapeutic modality for a variety of neuropsychiatric disorders. Reliably identifying in whom, where, and in what context to provide brain stimulation for optimal pain relief are fundamental challenges limiting the widespread implementation of central neuromodulation treatments for chronic pain. Current approaches to brain stimulation target empirically derived regions of interest to the disorder or targets with strong connections to these regions. However, complex, multidimensional experiences like chronic pain are more closely linked to patterns of coordinated activity across distributed large-scale functional networks. Recent advances in precision network neuroscience indicate that these networks are highly variable in their neuroanatomical organization across individuals. Here we review accumulating evidence that variable central representations of pain will likely pose a major barrier to implementation of population-derived analgesic brain stimulation targets. We propose network-level estimates as a more valid, robust, and reliable way to stratify personalized candidate regions. Finally, we review key background, methods, and implications for developing network topology-informed brain stimulation targets for chronic pain.
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Affiliation(s)
- Julian C. Motzkin
- Departments of Neurology and Anesthesia and Perioperative Care (Pain Management), University of California, San Francisco, San Francisco, CA, United States
| | - Ishan Kanungo
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, United States
| | - Mark D’Esposito
- Department of Psychology, University of California, Berkeley, Berkeley, CA, United States
| | - Prasad Shirvalkar
- Departments of Neurology and Anesthesia and Perioperative Care (Pain Management), University of California, San Francisco, San Francisco, CA, United States
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, United States
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26
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Blythe JS, Thomaidou MA, Peerdeman KJ, van Laarhoven AI, van Schothorst MM, Veldhuijzen DS, Evers AW. Placebo effects on cutaneous pain and itch: a systematic review and meta-analysis of experimental results and methodology. Pain 2023; 164:1181-1199. [PMID: 36718994 PMCID: PMC10184563 DOI: 10.1097/j.pain.0000000000002820] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 09/14/2022] [Accepted: 10/20/2022] [Indexed: 02/01/2023]
Abstract
ABSTRACT Placebo effects, positive treatment outcomes that go beyond treatment processes, can alter sensations through learning mechanisms. Understanding how methodological factors contribute to the magnitude of placebo effects will help define the mechanisms by which these effects occur. We conducted a systematic review and meta-analysis of experimental placebo studies in cutaneous pain and itch in healthy samples, focused on how differences in methodology contribute to the resulting placebo effect magnitude. We conducted meta-analyses by learning mechanism and sensation, namely, for classical conditioning with verbal suggestion, verbal suggestion alone, and observational learning, separately for pain and itch. We conducted subgroup analyses and meta-regression on the type of sensory stimuli, placebo treatment, number of acquisition and evocation trials, differences in calibrated intensities for placebo and control stimuli during acquisition, age, and sex. We replicated findings showing that a combination of classical conditioning with verbal suggestion induced larger placebo effects on pain ( k = 68, g = 0 . 59) than verbal suggestion alone ( k = 39, g = 0.38) and found a smaller effect for itch with verbal suggestion alone ( k = 7, g = 0.14). Using sham electrodes as placebo treatments corresponded with larger placebo effects on pain than when topical gels were used. Other methodological and demographic factors did not significantly affect placebo magnitudes. Placebo effects on pain and itch reliably occur in experimental settings with varied methods, and conditioning with verbal suggestion produced the strongest effects. Although methods may shape the placebo effect to some extent, these effects appear robust overall, and their underlying learning mechanisms may be harnessed for applications outside the laboratory.
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Affiliation(s)
- Joseph S. Blythe
- Health, Medical and Neuropsychology Unit, Leiden University, Leiden, the Netherlands
- Leiden Institute for Brain and Cognition, Leiden, the Netherlands
| | - Mia A. Thomaidou
- Health, Medical and Neuropsychology Unit, Leiden University, Leiden, the Netherlands
- Leiden Institute for Brain and Cognition, Leiden, the Netherlands
| | - Kaya J. Peerdeman
- Health, Medical and Neuropsychology Unit, Leiden University, Leiden, the Netherlands
- Leiden Institute for Brain and Cognition, Leiden, the Netherlands
| | - Antoinette I.M. van Laarhoven
- Health, Medical and Neuropsychology Unit, Leiden University, Leiden, the Netherlands
- Leiden Institute for Brain and Cognition, Leiden, the Netherlands
- Department of Psychiatry, Leiden University Medical Centre, Leiden, the Netherlands
| | | | - Dieuwke S. Veldhuijzen
- Health, Medical and Neuropsychology Unit, Leiden University, Leiden, the Netherlands
- Leiden Institute for Brain and Cognition, Leiden, the Netherlands
| | - Andrea W.M. Evers
- Health, Medical and Neuropsychology Unit, Leiden University, Leiden, the Netherlands
- Leiden Institute for Brain and Cognition, Leiden, the Netherlands
- Medical Delta Healthy Society, Leiden University, Technical University Delft, and Erasmus University Rotterdam, Rotterdam, the Netherlands
- Department of Psychiatry, Leiden University Medical Centre, Leiden, the Netherlands
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27
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Crawford LS, Meylakh N, Macey PM, Macefield VG, Keay KA, Henderson LA. Stimulus-independent and stimulus-dependent neural networks underpin placebo analgesia responsiveness in humans. Commun Biol 2023; 6:569. [PMID: 37244947 DOI: 10.1038/s42003-023-04951-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 05/18/2023] [Indexed: 05/29/2023] Open
Abstract
The neural circuits that regulate placebo analgesia responsivity are unknown, although engagement of brainstem pain modulatory regions is likely critical. Here we show in 47 participants that differences are present in neural circuit connectivity's in placebo responders versus non-responders. We distinguish stimulus-independent and stimulus-dependent neural networks that display altered connections between the hypothalamus, anterior cingulate cortex and midbrain periaqueductal gray matter. This dual regulatory system underpins an individual's ability to mount placebo analgesia.
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Affiliation(s)
- Lewis S Crawford
- School of Medical Sciences (Neuroscience), Brain and Mind Centre, University of Sydney, Sydney, NSW, 2006, Australia
| | - Noemi Meylakh
- School of Medical Sciences (Neuroscience), Brain and Mind Centre, University of Sydney, Sydney, NSW, 2006, Australia
| | - Paul M Macey
- UCLA School of Nursing, University of California, Los Angeles, CA, 90095, USA
| | - Vaughan G Macefield
- Department of Neuroscience, Monash University, Melbourne, VIC, 3800, Australia
| | - Kevin A Keay
- School of Medical Sciences (Neuroscience), Brain and Mind Centre, University of Sydney, Sydney, NSW, 2006, Australia
| | - Luke A Henderson
- School of Medical Sciences (Neuroscience), Brain and Mind Centre, University of Sydney, Sydney, NSW, 2006, Australia.
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28
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Büchel C. The role of expectations, control and reward in the development of pain persistence based on a unified model. eLife 2023; 12:81795. [PMID: 36972108 PMCID: PMC10042542 DOI: 10.7554/elife.81795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 03/20/2023] [Indexed: 03/29/2023] Open
Abstract
Chronic, or persistent pain affects more than 10% of adults in the general population. This makes it one of the major physical and mental health care problems. Although pain is an important acute warning signal that allows the organism to take action before tissue damage occurs, it can become persistent and its role as a warning signal thereby inadequate. Although per definition, pain can only be labeled as persistent after 3 months, the trajectory from acute to persistent pain is likely to be determined very early and might even start at the time of injury. The biopsychosocial model has revolutionized our understanding of chronic pain and paved the way for psychological treatments for persistent pain, which routinely outperform other forms of treatment. This suggests that psychological processes could also be important in shaping the very early trajectory from acute to persistent pain and that targeting these processes could prevent the development of persistent pain. In this review, we develop an integrative model and suggest novel interventions during early pain trajectories, based on predictions from this model.
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Affiliation(s)
- Christian Büchel
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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29
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Kang H, Miksche MS, Ellingsen DM. Association between personality traits and placebo effects: a preregistered systematic review and meta-analysis. Pain 2023; 164:494-508. [PMID: 35947877 DOI: 10.1097/j.pain.0000000000002753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 08/02/2022] [Indexed: 11/26/2022]
Abstract
ABSTRACT Placebo effects are ubiquitous yet highly variable between individuals and therefore strongly affect clinical trial outcomes such as pain relief. It is unclear whether dispositional psychological traits influence responsiveness to placebo. This preregistered meta-analysis and systematic review synthesized the literature investigating the association between personality traits and placebo effects. Based on 21 studies with 798 participants, we performed formal meta-analyses for 10 different personality traits, including behavioral inhibition, fun seeking, goal-drive persistence, reward responsiveness, empathic concern, empathic fantasy, perspective-taking, personal distress, optimism, and anxiety. We did not find evidence of associations between any of these traits and magnitude of placebo effects, which was supported by equivalence tests. Furthermore, we did not find evidence for moderating factors such as placebo manipulation type (conditioning or nonconditioning) or condition (pain or nonpain). These findings challenge the notion that personality influences responsiveness to placebos and contradict its utility for identifying placebo "responders" and "nonresponders."
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Affiliation(s)
- Heemin Kang
- Department of Psychology, University of Oslo, Norway
- Norwegian Centre for Mental Disorders Research, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
| | | | - Dan-Mikael Ellingsen
- Department of Psychology, University of Oslo, Norway
- Division of Radiology and Nuclear Medicine, Department of Physics and Computational Radiology, Oslo University Hospital, Oslo, Norway
- School of Health Sciences, Kristiania University College, Oslo, Norway
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30
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Savallampi M, Maallo AMS, Shaikh S, McGlone F, Bariguian-Revel FJ, Olausson H, Boehme R. Social Touch Reduces Pain Perception—An fMRI Study of Cortical Mechanisms. Brain Sci 2023; 13:brainsci13030393. [PMID: 36979203 PMCID: PMC10046093 DOI: 10.3390/brainsci13030393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 03/03/2023] Open
Abstract
Unmyelinated low-threshold mechanoreceptors (C-tactile, CT) in the human skin are important for signaling information about hedonic aspects of touch. We have previously reported that CT-targeted brush stroking by means of a robot reduces experimental mechanical pain. To improve the ecological validity of the stimulation, we developed standardized human–human touch gestures for signaling attention and calming. The attention gesture is characterized by tapping of the skin and is perceived as neither pleasant nor unpleasant, i.e., neutral. The calming gesture is characterized by slow stroking of the skin and is perceived as moderately to very pleasant. Furthermore, the attention (tapping) gesture is ineffective, whereas the calming (stroking) gesture is effective in activating CT-afferents. We conducted an fMRI study (n = 32) and capitalized on the previous development of touch gestures. We also developed an MR compatible stimulator for high-precision mechanical pain stimulation of the thenar region of the hand. Skin-to-skin touching (stroking or tapping) was applied and was followed by low and high pain. When the stroking gesture preceded pain, the pain was rated as less intense. When the tapping gesture preceded the pain, the pain was rated as more intense. Individual pain perception related to insula activation, but the activation was not higher for stroking than for tapping in any brain area during the stimulation period. However, during the evaluation period, stronger activation in the periaqueductal gray matter was observed after calming touch compared to after tapping touch. This finding invites speculation that human–human gentle skin stroking, effective in activating CT-afferents, reduced pain through neural processes involving CT-afferents and the descending pain pathway.
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Affiliation(s)
- Mattias Savallampi
- Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University, 58185 Linköping, Sweden
| | - Anne M. S. Maallo
- Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University, 58185 Linköping, Sweden
| | - Sumaiya Shaikh
- Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University, 58185 Linköping, Sweden
| | - Francis McGlone
- Research Centre Brain & Behavior, Liverpool John Moores University, Liverpool L3 5UZ, UK
| | | | - Håkan Olausson
- Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University, 58185 Linköping, Sweden
- Department of Clinical Neurophysiology, Linköping University Hospital, 58185 Linköping, Sweden
- Center for Medical Imaging and Visualization, Linköping University, 58185 Linköping, Sweden
| | - Rebecca Boehme
- Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University, 58185 Linköping, Sweden
- Center for Medical Imaging and Visualization, Linköping University, 58185 Linköping, Sweden
- Correspondence:
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31
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Desch S, Schweinhardt P, Seymour B, Flor H, Becker S. Evidence for dopaminergic involvement in endogenous modulation of pain relief. eLife 2023; 12:e81436. [PMID: 36722857 PMCID: PMC9988263 DOI: 10.7554/elife.81436] [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: 06/27/2022] [Accepted: 01/31/2023] [Indexed: 02/02/2023] Open
Abstract
Relief of ongoing pain is a potent motivator of behavior, directing actions to escape from or reduce potentially harmful stimuli. Whereas endogenous modulation of pain events is well characterized, relatively little is known about the modulation of pain relief and its corresponding neurochemical basis. Here, we studied pain modulation during a probabilistic relief-seeking task (a 'wheel of fortune' gambling task), in which people actively or passively received reduction of a tonic thermal pain stimulus. We found that relief perception was enhanced by active decisions and unpredictability, and greater in high novelty-seeking trait individuals, consistent with a model in which relief is tuned by its informational content. We then probed the roles of dopaminergic and opioidergic signaling, both of which are implicated in relief processing, by embedding the task in a double-blinded cross-over design with administration of the dopamine precursor levodopa and the opioid receptor antagonist naltrexone. We found that levodopa enhanced each of these information-specific aspects of relief modulation but no significant effects of the opioidergic manipulation. These results show that dopaminergic signaling has a key role in modulating the perception of pain relief to optimize motivation and behavior.
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Affiliation(s)
- Simon Desch
- Institute of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg UniversityMannheimGermany
- Clinical Psychology, Department of Experimental Psychology, Heinrich Heine University DüsseldorfDüsseldorfGermany
| | - Petra Schweinhardt
- Integrative Spinal Research, Department of Chiropractic Medicine, Balgrist University Hospital, University of ZurichZurichSwitzerland
| | - Ben Seymour
- Wellcome Centre for Integrative Neuroimaging, John Radcliffe HospitalOxfordUnited Kingdom
| | - Herta Flor
- Institute of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg UniversityMannheimGermany
| | - Susanne Becker
- Institute of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg UniversityMannheimGermany
- Clinical Psychology, Department of Experimental Psychology, Heinrich Heine University DüsseldorfDüsseldorfGermany
- Integrative Spinal Research, Department of Chiropractic Medicine, Balgrist University Hospital, University of ZurichZurichSwitzerland
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32
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Jiao Y, Gao P, Dong L, Ding X, Meng Y, Qian J, Gao T, Wang R, Jiang T, Zhang Y, Kong D, Wu Y, Chen S, Xu S, Tang D, Luo P, Wu M, Meng L, Wen D, Wu C, Zhang G, Shi X, Yu W, Rong W. Molecular identification of bulbospinal ON neurons by GPER, which drives pain and morphine tolerance. J Clin Invest 2023; 133:e154588. [PMID: 36346677 PMCID: PMC9797334 DOI: 10.1172/jci154588] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 11/02/2022] [Indexed: 11/09/2022] Open
Abstract
The rostral ventromedial medulla (RVM) exerts bidirectional descending modulation of pain attributable to the activity of electrophysiologically identified pronociceptive ON and antinociceptive OFF neurons. Here, we report that GABAergic ON neurons specifically express G protein-coupled estrogen receptor (GPER). GPER+ neurons exhibited characteristic ON-like responses upon peripheral nociceptive stimulation. Optogenetic activation of GPER+ neurons facilitated, but their ablation abrogated, pain. Furthermore, activation of GPER caused depolarization of ON cells, potentiated pain, and ameliorated morphine analgesia through desensitizing μ-type opioid receptor-mediated (MOR-mediated) activation of potassium currents. In contrast, genetic ablation or pharmacological blockade of GPER attenuated pain, enhanced morphine analgesia, and delayed the development of morphine tolerance in diverse preclinical pain models. Our data strongly indicate that GPER is a marker for GABAergic ON cells and illuminate the mechanisms underlying hormonal regulation of pain and analgesia, thus highlighting GPER as a promising target for the treatment of pain and opioid tolerance.
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Affiliation(s)
- Yingfu Jiao
- Department of Anatomy and Physiology and
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Po Gao
- Department of Anatomy and Physiology and
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Li Dong
- Department of Anatomy and Physiology and
| | | | - Youqiang Meng
- Department of Anatomy and Physiology and
- Department of Neurosurgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Chongming Branch, Shanghai University of Medicine and Health Sciences Affiliated Chongming Hospital, Shanghai, China
| | | | - Ting Gao
- Department of Anatomy and Physiology and
| | - Ruoxi Wang
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Tao Jiang
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yunchun Zhang
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Dexu Kong
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yi Wu
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Sihan Chen
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Saihong Xu
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Dan Tang
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ping Luo
- Department of Anatomy and Physiology and
| | - Meimei Wu
- Department of Anatomy and Physiology and
| | - Li Meng
- Department of Anatomy and Physiology and
| | - Daxiang Wen
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Changhao Wu
- School of Biosciences and Medicine, University of Surrey, Guildford, United Kingdom
| | | | - Xueyin Shi
- Department of Anesthesiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Weifeng Yu
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Weifang Rong
- Department of Anatomy and Physiology and
- Department of Anesthesiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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33
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Kunkel A, Bingel U. [Placebo effects in analgesia : Influence of expectations on the efficacy and tolerability of analgesic treatment]. Schmerz 2023; 37:59-71. [PMID: 36637498 PMCID: PMC9889476 DOI: 10.1007/s00482-022-00685-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2022] [Indexed: 01/14/2023]
Abstract
Expectations of patients influence the perception and neuronal processing of acute and chronic pain and modulate the effectiveness of analgesic treatment. The expectation of treatment is not only the most important determinant of placebo analgesia. Expectations of treatment also influence the efficacy and tolerability of "active" pharmacological and non-pharmacological treatment of pain. Recent insights into the psychological and neurobiological mechanisms underlying the clinically relevant effects of treatment expectations enable and call for the systematic integration and modulation of treatment expectations into analgesic treatment concepts. Such a strategy promises to optimize analgesic treatment and to prevent or reduce the burden of unwanted side effects and the misuse of analgesics, particularly of opioids. This review highlights the current concepts, recent achievements and also challenges and key open research questions.
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Affiliation(s)
- Angelika Kunkel
- Klinik für Neurologie, Zentrum für translationale Neuro- und Verhaltenswissenschaften, Universitätsklinikum Essen, Hufelandstr. 55, 45147, Essen, Deutschland.
| | - Ulrike Bingel
- Klinik für Neurologie, Zentrum für translationale Neuro- und Verhaltenswissenschaften, Universitätsklinikum Essen, Hufelandstr. 55, 45147, Essen, Deutschland
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34
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Trøstheim M, Eikemo M, Haaker J, Frost JJ, Leknes S. Opioid antagonism in humans: a primer on optimal dose and timing for central mu-opioid receptor blockade. Neuropsychopharmacology 2023; 48:299-307. [PMID: 35978096 PMCID: PMC7613944 DOI: 10.1038/s41386-022-01416-z] [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: 03/24/2022] [Revised: 07/06/2022] [Accepted: 07/28/2022] [Indexed: 12/26/2022]
Abstract
Non-human animal studies outline precise mechanisms of central mu-opioid regulation of pain, stress, affiliation and reward processing. In humans, pharmacological blockade with non-selective opioid antagonists such as naloxone and naltrexone is typically used to assess involvement of the mu-opioid system in such processing. However, robust estimates of the opioid receptor blockade achieved by opioid antagonists are missing. Dose and timing schedules are highly variable and often based on single studies. Here, we provide a detailed analysis of central opioid receptor blockade after opioid antagonism based on existing positron emission tomography data. We also create models for estimating opioid receptor blockade with intravenous naloxone and oral naltrexone. We find that common doses of intravenous naloxone (0.10-0.15 mg/kg) and oral naltrexone (50 mg) are more than sufficient to produce full blockade of central MOR (>90% receptor occupancy) for the duration of a typical experimental session (~60 min), presumably due to initial super saturation of receptors. Simulations indicate that these doses also produce high KOR blockade (78-100%) and some DOR blockade (10% with naltrexone and 48-74% with naloxone). Lower doses (e.g., 0.01 mg/kg intravenous naloxone) are estimated to produce less DOR and KOR blockade while still achieving a high level of MOR blockade for ~30 min. The models and simulations form the basis of two novel web applications for detailed planning and evaluation of experiments with opioid antagonists. These tools and recommendations enable selection of appropriate antagonists, doses and assessment time points, and determination of the achieved receptor blockade in previous studies.
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Affiliation(s)
- Martin Trøstheim
- Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway. .,Department of Psychology, University of Oslo, Oslo, Norway.
| | - Marie Eikemo
- grid.5510.10000 0004 1936 8921Department of Psychology, University of Oslo, Oslo, Norway
| | - Jan Haaker
- grid.13648.380000 0001 2180 3484Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Siri Leknes
- grid.55325.340000 0004 0389 8485Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway ,grid.5510.10000 0004 1936 8921Department of Psychology, University of Oslo, Oslo, Norway
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35
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Bannister K, Hughes S. One size does not fit all: towards optimising the therapeutic potential of endogenous pain modulatory systems. Pain 2023; 164:e5-e9. [PMID: 35594517 PMCID: PMC9756434 DOI: 10.1097/j.pain.0000000000002697] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 04/20/2022] [Accepted: 04/28/2022] [Indexed: 01/09/2023]
Affiliation(s)
- Kirsty Bannister
- Central Modulation of Pain Lab, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Sam Hughes
- Pain Modulation Lab, Brain Research, and Imaging Centre (BRIC), School of Psychology, University of Plymouth, Plymouth, United Kingdom
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36
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Szikszay TM, Adamczyk WM, Panskus J, Heimes L, David C, Gouverneur P, Luedtke K. Psychological mechanisms of offset analgesia: The effect of expectancy manipulation. PLoS One 2023; 18:e0280579. [PMID: 36649306 PMCID: PMC9844857 DOI: 10.1371/journal.pone.0280579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 01/03/2023] [Indexed: 01/18/2023] Open
Abstract
A frequently used paradigm to quantify endogenous pain modulation is offset analgesia, which is defined as a disproportionate large reduction in pain following a small decrease in a heat stimulus. The aim of this study was to determine whether suggestion influences the magnitude of offset analgesia in healthy participants. A total of 97 participants were randomized into three groups (hypoalgesic group, hyperalgesic group, control group). All participants received four heat stimuli (two constant trials and two offset trials) to the ventral, non-dominant forearm while they were asked to rate their perceived pain using a computerized visual analogue scale. In addition, electrodermal activity was measured during each heat stimulus. Participants in both intervention groups were given a visual and verbal suggestion about the expected pain response in an hypoalgesic and hyperalgesic manner. The control group received no suggestion. In all groups, significant offset analgesia was provoked, indicated by reduced pain ratings (p < 0.001) and enhanced electrodermal activity level (p < 0.01). A significant group difference in the magnitude of offset analgesia was found between the three groups (F[2,94] = 4.81, p < 0.05). Participants in the hyperalgesic group perceived significantly more pain than the hypoalgesic group (p = 0.031) and the control group (p < 0.05). However, the electrodermal activity data did not replicate this trend (p > 0.05). The results of this study indicate that suggestion can be effective to reduce but not increase endogenous pain modulation quantified by offset analgesia in healthy participants.
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Affiliation(s)
- Tibor M Szikszay
- Institute of Health Sciences, Department of Physiotherapy, Pain and Exercise Research Luebeck (P.E.R.L.), Universität zu Lübeck, Luebeck, Germany
| | - Waclaw M Adamczyk
- Institute of Health Sciences, Department of Physiotherapy, Pain and Exercise Research Luebeck (P.E.R.L.), Universität zu Lübeck, Luebeck, Germany.,Laboratory of Pain Research, Institute of Physiotherapy and Health Sciences, The Jerzy Kukuczka Academy of Physical Education, Katowice, Poland
| | - Janina Panskus
- Institute of Health Sciences, Department of Physiotherapy, Pain and Exercise Research Luebeck (P.E.R.L.), Universität zu Lübeck, Luebeck, Germany
| | - Lotte Heimes
- Institute of Health Sciences, Department of Physiotherapy, Pain and Exercise Research Luebeck (P.E.R.L.), Universität zu Lübeck, Luebeck, Germany
| | - Carolin David
- Institute of Health Sciences, Department of Physiotherapy, Pain and Exercise Research Luebeck (P.E.R.L.), Universität zu Lübeck, Luebeck, Germany
| | - Philip Gouverneur
- Institute of Medical Informatics, University of Luebeck, Luebeck, Germany
| | - Kerstin Luedtke
- Institute of Health Sciences, Department of Physiotherapy, Pain and Exercise Research Luebeck (P.E.R.L.), Universität zu Lübeck, Luebeck, Germany
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Tu Y, Zhang L, Kong J. Placebo and nocebo effects: from observation to harnessing and clinical application. Transl Psychiatry 2022; 12:524. [PMID: 36564374 PMCID: PMC9789123 DOI: 10.1038/s41398-022-02293-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 12/12/2022] [Accepted: 12/15/2022] [Indexed: 12/25/2022] Open
Abstract
Placebo and nocebo effects are salubrious benefits and negative outcomes attributable to non-specific symbolic components. Leveraging advanced experimental and analytical approaches, recent studies have elucidated complicated neural mechanisms that may serve as a solid basis for harnessing the powerful self-healing and self-harming capacities and applying these findings to improve medical practice and minimize the unintended exacerbation of symptoms in medical practice. We review advances in employing psychosocial, pharmacological, and neuromodulation approaches to modulate/harness placebo and nocebo effects. While these approaches show promising potential, translating these research findings into clinical settings still requires careful methodological, technical, and ethical considerations.
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Affiliation(s)
- Yiheng Tu
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China. .,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China.
| | - Libo Zhang
- grid.9227.e0000000119573309CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China ,grid.410726.60000 0004 1797 8419Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Jian Kong
- grid.32224.350000 0004 0386 9924Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA USA
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38
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Research progress on the mechanism of chronic neuropathic pain. IBRO Neurosci Rep 2022; 14:80-85. [PMID: 36632243 PMCID: PMC9827377 DOI: 10.1016/j.ibneur.2022.12.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Accepted: 12/17/2022] [Indexed: 12/24/2022] Open
Abstract
Chronic neuropathic pain (CNP) refers to pain that lasts for more than three months due to a disease or an injury to the somatosensory nervous system. The incidence of CNP has been increasing in the world, causing it to become a global concern and patients often experience spontaneous pain, hyperalgesia, abnormal pain or even abnormal sensation as some of its main symptoms. In addition to serious pain and poor physical health, CNP also negatively affects patients' mental health, thus impacting the overall quality of their lives. The pathogenesis of CNP is not clear, but some studies have proved that central sensitization, peripheral sensitization, neuroinflammation, dysfunction in descending nociceptive modulatory systems, oxidative stress reaction, activation of glial cells and psychological factors play an important role in the occurrence and development of CNP. In this context, this article summarizes the current research progress on the mechanism of CNP to provide a basis for further research in preventing and treating the disease.
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Targeting neural correlates of placebo effects. COGNITIVE, AFFECTIVE, & BEHAVIORAL NEUROSCIENCE 2022; 23:217-236. [PMID: 36517733 DOI: 10.3758/s13415-022-01039-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/26/2022] [Indexed: 12/15/2022]
Abstract
Harnessing the placebo effects would prompt critical ramifications for research and clinical practice. Noninvasive brain stimulation (NIBS) techniques, such as transcranial magnetic stimulation and multifocal transcranial electric stimulation, could manipulate the placebo response by modulating the activity and excitability of its neural correlates. To identify potential stimulation targets, we conducted a meta-analysis to investigate placebo-associated regions in healthy volunteers, including studies with emotional components and painful stimuli. Using biophysical modeling, we identified NIBS solutions to manipulate placebo effects by targeting either a single key region or multiple connected areas. Moving to a network-oriented approach, we then ran a quantitative network mapping analysis on the functional connectivity profile of clusters emerging from the meta-analysis. As a result, we suggest a multielectrode optimized montage engaging the connectivity patterns of placebo-associated functional brain networks. These NIBS solutions hope to provide a starting point to actively control, modulate or enhance placebo effects in future clinical studies and cognitive enhancement studies.
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40
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Atlas LY, Dildine TC, Palacios-Barrios EE, Yu Q, Reynolds RC, Banker LA, Grant SS, Pine DS. Instructions and experiential learning have similar impacts on pain and pain-related brain responses but produce dissociations in value-based reversal learning. eLife 2022; 11:73353. [PMID: 36317867 PMCID: PMC9681218 DOI: 10.7554/elife.73353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/25/2022] [Indexed: 11/22/2022] Open
Abstract
Recent data suggest that interactions between systems involved in higher order knowledge and associative learning drive responses during value-based learning. However, it is unknown how these systems impact subjective responses, such as pain. We tested how instructions and reversal learning influence pain and pain-evoked brain activation. Healthy volunteers (n=40) were either instructed about contingencies between cues and aversive outcomes or learned through experience in a paradigm where contingencies reversed three times. We measured predictive cue effects on pain and heat-evoked brain responses using functional magnetic resonance imaging. Predictive cues dynamically modulated pain perception as contingencies changed, regardless of whether participants received contingency instructions. Heat-evoked responses in the insula, anterior cingulate, and other regions updated as contingencies changed, and responses in the prefrontal cortex mediated dynamic cue effects on pain, whereas responses in the brainstem’s rostroventral medulla (RVM) were shaped by initial contingencies throughout the task. Quantitative modeling revealed that expected value was shaped purely by instructions in the Instructed Group, whereas expected value updated dynamically in the Uninstructed Group as a function of error-based learning. These differences were accompanied by dissociations in the neural correlates of value-based learning in the rostral anterior cingulate, thalamus, and posterior insula, among other regions. These results show how predictions dynamically impact subjective pain. Moreover, imaging data delineate three types of networks involved in pain generation and value-based learning: those that respond to initial contingencies, those that update dynamically during feedback-driven learning as contingencies change, and those that are sensitive to instruction. Together, these findings provide multiple points of entry for therapies designs to impact pain.
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Affiliation(s)
- Lauren Y Atlas
- National Center for Complementary and Integrative Health, National Institutes of Health
- National Institute on Drug Abuse, National Institutes of Health
- National Institute of Mental Health, National Institutes of Health
| | - Troy C Dildine
- National Center for Complementary and Integrative Health, National Institutes of Health
- Department of Clinical Neuroscience, Karolinska Institutet
| | | | - Qingbao Yu
- National Center for Complementary and Integrative Health, National Institutes of Health
| | | | - Lauren A Banker
- National Center for Complementary and Integrative Health, National Institutes of Health
| | - Shara S Grant
- National Center for Complementary and Integrative Health, National Institutes of Health
| | - Daniel S Pine
- National Institute of Mental Health, National Institutes of Health
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41
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Bosak N, Branco P, Kuperman P, Buxbaum C, Cohen RM, Fadel S, Zubeidat R, Hadad R, Lawen A, Saadon‐Grosman N, Sterling M, Granovsky Y, Apkarian AV, Yarnitsky D, Kahn I. Brain Connectivity Predicts Chronic Pain in Acute Mild Traumatic Brain Injury. Ann Neurol 2022; 92:819-833. [PMID: 36082761 PMCID: PMC9826527 DOI: 10.1002/ana.26463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 07/23/2022] [Accepted: 07/25/2022] [Indexed: 01/11/2023]
Abstract
OBJECTIVES Previous studies have established the role of the cortico-mesolimbic and descending pain modulation systems in chronic pain prediction. Mild traumatic brain injury (mTBI) is an acute pain model where chronic pain is prevalent and complicated for prediction. In this study, we set out to study whether functional connectivity (FC) of the nucleus accumbens (NAc) and the periaqueductal gray matter (PAG) is predictive of pain chronification in early-acute mTBI. METHODS To estimate FC, resting-state functional magnetic resonance imaging (fMRI) of 105 participants with mTBI following a motor vehicle collision was acquired within 72 hours post-accident. Participants were classified according to pain ratings provided at 12-months post-collision into chronic pain (head/neck pain ≥30/100, n = 44) and recovery (n = 61) groups, and their FC maps were compared. RESULTS The chronic pain group exhibited reduced negative FC between NAc and a region within the primary motor cortex corresponding with the expected representation of the area of injury. A complementary pattern was also demonstrated between PAG and the primary somatosensory cortex. PAG and NAc also shared increased FC to the rostral anterior cingulate cortex (rACC) within the recovery group. Brain connectivity further shows high classification accuracy (area under the curve [AUC] = .86) for future chronic pain, when combined with an acute pain intensity report. INTERPRETATION FC features obtained shortly after mTBI predict its transition to long-term chronic pain, and may reflect an underlying interaction of injury-related primary sensorimotor cortical areas with the mesolimbic and pain modulation systems. Our findings indicate a potential predictive biomarker and highlight targets for future early preventive interventions. ANN NEUROL 2022;92:819-833.
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Affiliation(s)
- Noam Bosak
- Rappaport Faculty of MedicineTechnion – Israel Institute of TechnologyHaifaIsrael,Department of NeurologyRambam Health Care CampusHaifaIsrael
| | - Paulo Branco
- Department of NeuroscienceNorthwestern University Medical SchoolChicagoIL
| | - Pora Kuperman
- Rappaport Faculty of MedicineTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Chen Buxbaum
- Rappaport Faculty of MedicineTechnion – Israel Institute of TechnologyHaifaIsrael,Department of NeurologyRambam Health Care CampusHaifaIsrael
| | - Ruth Manor Cohen
- Rappaport Faculty of MedicineTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Shiri Fadel
- Department of NeurologyRambam Health Care CampusHaifaIsrael
| | - Rabab Zubeidat
- Rappaport Faculty of MedicineTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Rafi Hadad
- Department of NeurologyRambam Health Care CampusHaifaIsrael
| | - Amir Lawen
- Rappaport Faculty of MedicineTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Noam Saadon‐Grosman
- Department of Medical Neurobiology, Faculty of MedicineThe Hebrew UniversityJerusalemIsrael
| | - Michele Sterling
- RECOVER Injury Research Centre, NHMRC Centre of Research Excellence in Road Traffic Injury RecoveryThe University of QueenslandBrisbaneAustralia
| | - Yelena Granovsky
- Rappaport Faculty of MedicineTechnion – Israel Institute of TechnologyHaifaIsrael
| | | | - David Yarnitsky
- Rappaport Faculty of MedicineTechnion – Israel Institute of TechnologyHaifaIsrael,Department of NeurologyRambam Health Care CampusHaifaIsrael
| | - Itamar Kahn
- Rappaport Faculty of MedicineTechnion – Israel Institute of TechnologyHaifaIsrael
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Hays Weeks CC, Simmons AN, Strigo IA, Timtim S, Ellis RJ, Keltner JR. Distal neuropathic pain in HIV is associated with functional connectivity patterns in default mode and salience networks. FRONTIERS IN PAIN RESEARCH (LAUSANNE, SWITZERLAND) 2022; 3:1004060. [PMID: 36313219 PMCID: PMC9596968 DOI: 10.3389/fpain.2022.1004060] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 09/26/2022] [Indexed: 11/05/2022]
Abstract
HIV-associated distal neuropathic pain (DNP) is one of the most prevalent, disabling, and treatment-resistant complications of HIV, but its biological underpinnings are incompletely understood. While data specific to mechanisms underlying HIV DNP are scarce, functional neuroimaging of chronic pain more broadly implicates the role of altered resting-state functional connectivity within and between salience network (SN) and default mode network (DMN) regions. However, it remains unclear the extent to which HIV DNP is associated with similar alterations in connectivity. The current study aimed to bridge this gap in the literature through examination of resting-state functional connectivity patterns within SN and DMN regions among people with HIV (PWH) with and without DNP. Resting state functional magnetic resonance imaging (rs-fMRI) scans were completed among 62 PWH with HIV-associated peripheral neuropathy, of whom 27 reported current DNP and 35 did not. Using subgrouping group iterative multiple estimation, we compared connectivity patterns in those with current DNP to those without. We observed weaker connectivity between the medial prefrontal cortex (MPFC) and posterior cingulate cortex (PCC) and stronger connectivity between the anterior cingulate cortex (ACC) and thalamus among those reporting DNP. Overall, these findings implicate altered within DMN (i.e., MPFC-PCC) and within SN (i.e., ACC-thalamus) connectivity as potential manifestations of adaptation to pain from neuropathy and/or mechanisms underlying the development/maintenance of DNP. Findings are discussed in the context of differential brain response to pain (i.e., mind wandering, pain aversion, pain facilitation/inhibition) and therapeutic implications.
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Affiliation(s)
| | - Alan N. Simmons
- CESAMH, VA San Diego Healthcare System, San Diego, United States,Department of Psychiatry, UC San Diego, La Jolla, CA, United States
| | - Irina A. Strigo
- Department of Psychiatry, UC San Francisco, CA, United States
| | - Sara Timtim
- Department of Psychiatry, UC San Diego, La Jolla, CA, United States
| | - Ronald J. Ellis
- Department of Psychiatry, UC San Diego, La Jolla, CA, United States,Department of Neurosciences, UC San Diego, La Jolla, CA, United States
| | - John R. Keltner
- CESAMH, VA San Diego Healthcare System, San Diego, United States,Department of Psychiatry, UC San Diego, La Jolla, CA, United States,Correspondence: John R. Keltner
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43
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Ma X, Chen W, Yang NN, Wang L, Hao XW, Tan CX, Li HP, Liu CZ. Potential mechanisms of acupuncture for neuropathic pain based on somatosensory system. Front Neurosci 2022; 16:940343. [PMID: 36203799 PMCID: PMC9530146 DOI: 10.3389/fnins.2022.940343] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 08/29/2022] [Indexed: 12/04/2022] Open
Abstract
Neuropathic pain, caused by a lesion or disease of the somatosensory system, is common and distressing. In view of the high human and economic burden, more effective treatment strategies were urgently needed. Acupuncture has been increasingly used as an adjuvant or complementary therapy for neuropathic pain. Although the therapeutic effects of acupuncture have been demonstrated in various high-quality randomized controlled trials, there is significant heterogeneity in the underlying mechanisms. This review aimed to summarize the potential mechanisms of acupuncture on neuropathic pain based on the somatosensory system, and guided for future both foundational and clinical studies. Here, we argued that acupuncture may have the potential to inhibit neuronal activity caused by neuropathic pain, through reducing the activation of pain-related ion channels and suppressing glial cells (including microglia and astrocytes) to release inflammatory cytokines, chemokines, amongst others. Meanwhile, acupuncture as a non-pharmacologic treatment, may have potential to activate descending pain control system via increasing the level of spinal or brain 5-hydroxytryptamine (5-HT), norepinephrine (NE), and opioid peptides. And the types of endogenously opioid peptides was influenced by electroacupuncture-frequency. The cumulative evidence demonstrated that acupuncture provided an alternative or adjunctive therapy for neuropathic pain.
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Affiliation(s)
- Xin Ma
- School of Acupuncture-Moxibustion and Tuina, Shandong University of Traditional Chinese Medicine, Jinan, China
- School of Acupuncture-Moxibustion and Tuina, International Acupuncture and Moxibustion Innovation Institute, Beijing University of Chinese Medicine, Beijing, China
| | - Wen Chen
- School of Acupuncture-Moxibustion and Tuina, International Acupuncture and Moxibustion Innovation Institute, Beijing University of Chinese Medicine, Beijing, China
| | - Na-Na Yang
- School of Acupuncture-Moxibustion and Tuina, International Acupuncture and Moxibustion Innovation Institute, Beijing University of Chinese Medicine, Beijing, China
| | - Lu Wang
- School of Acupuncture-Moxibustion and Tuina, International Acupuncture and Moxibustion Innovation Institute, Beijing University of Chinese Medicine, Beijing, China
| | - Xiao-Wan Hao
- School of Acupuncture-Moxibustion and Tuina, International Acupuncture and Moxibustion Innovation Institute, Beijing University of Chinese Medicine, Beijing, China
| | - Chun-Xia Tan
- School of Acupuncture-Moxibustion and Tuina, International Acupuncture and Moxibustion Innovation Institute, Beijing University of Chinese Medicine, Beijing, China
| | - Hong-Ping Li
- School of Acupuncture-Moxibustion and Tuina, International Acupuncture and Moxibustion Innovation Institute, Beijing University of Chinese Medicine, Beijing, China
- Hong-Ping Li,
| | - Cun-Zhi Liu
- School of Acupuncture-Moxibustion and Tuina, Shandong University of Traditional Chinese Medicine, Jinan, China
- School of Acupuncture-Moxibustion and Tuina, International Acupuncture and Moxibustion Innovation Institute, Beijing University of Chinese Medicine, Beijing, China
- *Correspondence: Cun-Zhi Liu,
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44
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Fiorio M, Braga M, Marotta A, Villa-Sánchez B, Edwards MJ, Tinazzi M, Barbiani D. Functional neurological disorder and placebo and nocebo effects: shared mechanisms. Nat Rev Neurol 2022; 18:624-635. [PMID: 36075980 DOI: 10.1038/s41582-022-00711-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2022] [Indexed: 11/09/2022]
Abstract
Functional neurological disorder (FND) is characterized by neurological symptoms that cannot be explained by a structural neurological cause. Among the different aetiological models that have been proposed for FND, of note is the Bayesian predictive coding model, which posits that perception relies on top-down cortical predictions (priors) to infer the source of incoming sensory information. This model can also apply to non-pathological experiences, such as placebo and nocebo effects, wherein sensory information is shaped by prior expectations and learning. To date, most studies of the relationship between placebo and nocebo effects and FND have focused on the use of placebos for diagnosis and treatment of FND. Here, we propose that this relationship might go beyond diagnosis and therapy. We develop a framework in which shared cognitive, personality and neuroanatomical factors justify the consideration of a deeper link between FND and placebo and nocebo effects. This new perspective might offer guidance for clarification of the pathogenesis of FND and for the identification of potential biomarkers and therapeutic targets.
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Affiliation(s)
- Mirta Fiorio
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
| | - Miriam Braga
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Angela Marotta
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | | | - Mark J Edwards
- Institute of Molecular and Clinical Sciences, St George's University of London, London, UK
| | - Michele Tinazzi
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Diletta Barbiani
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
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45
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Feldman HA, Feldman JA, Miller CC, Walsh G, Tyson JE. Informed Consent for Placebo-Controlled Trials: Do Ethics and Science Conflict? Ethics Hum Res 2022; 44:42-48. [PMID: 36047276 PMCID: PMC9841466 DOI: 10.1002/eahr.500142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The use of a placebo has been considered the best method for controlling bias in a prospective randomized clinical trial and provides the most rigorous test of treatment efficacy for evaluating a medical therapy. Placebos commonly produce clinically important effects particularly in studies where the primary outcomes are subjective. Yet the potential beneficial or harmful effects of placebos are often not addressed in designing a clinical trial, calculating the sample size, seeking consent, or interpreting clinical trial results. In this manuscript, we use an actual study to indicate three approaches that might be considered in seeking informed consent for placebo-controlled trials, and we explore the fundamental ethical and scientific complexities involved with each.
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Affiliation(s)
- Hope A. Feldman
- Department of Thoracic and Cardiovascular Surgery at the University of Texas MD Anderson Cancer Center
| | - James A. Feldman
- Department of Emergency Medicine at the Boston Medical Center at the Boston University School of Medicine
| | - Charles C. Miller
- University of Texas Health Science Center at Houston in the McGovern Medical School
| | - Garrett Walsh
- Department of Thoracic and Cardiovascular Surgery at the University of Texas MD Anderson Cancer Center
| | - Jon E. Tyson
- University of Texas Health Science Center at Houston in the McGovern Medical School
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46
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Liu LY, Li X, Tian ZL, Zhang Q, Shen ZF, Wei W, Guo XL, Chen L, Su MH, Yang L, Yu SY, Yang J. Acupuncture modulates the frequency-specific functional connectivity density in primary dysmenorrhea. Front Neurosci 2022; 16:917721. [PMID: 36051643 PMCID: PMC9426343 DOI: 10.3389/fnins.2022.917721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 07/15/2022] [Indexed: 11/13/2022] Open
Abstract
BackgroundThe study aimed to investigate how acupuncture modulates brain activities across multiple frequency bands to achieve therapeutic effects in PDM.MethodsA total of 47 patients with PDM were randomly assigned to the verum acupuncture group and sham acupuncture group with three menstrual cycles of the acupuncture course. The fMRI scans, visual analog scale (VAS) scores, and other clinical evaluations were assessed at baseline and after three menstrual-cycles treatments. The global functional connectivity density (gFCD) analyses were performed between the pre-and post-acupuncture course of two groups at full-low frequency band, Slow-3 band, Slow-4 band, and Slow-5 band.ResultsAfter the acupuncture treatments, the patients with PDM in the verum acupuncture group showed significantly decreased VAS scores (p < 0.05). The frequency-dependent gFCD alternations were found in the verum acupuncture group, altered regions including DLPFC, somatosensory cortex, anterior cingulate cortex (ACC), middle cingulate cortex (MCC), precuneus, hippocampus, and insula. The sham acupuncture modulated regions including angular gyrus, inferior frontal gyrus, and hippocampus. The gFCD alternation in DLPFC at the Slow-5 band was negatively in the patients with PDM following verum acupuncture, and S2 at the Slow-4 band was positively correlated with VAS scores.ConclusionThese findings supported that verum acupuncture could effectively modulate frequency-dependent gFCD in PDM by influencing abnormal DLPFC at Slow-5 band and hippocampus at the Slow-3 band. The outcome of this study may shed light on enhancing the potency of acupuncture in clinical practice.
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Affiliation(s)
- Li-Ying Liu
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Xiang Li
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Zi-Lei Tian
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Qi Zhang
- Chongqing Hospital of Traditional Chinese Medicine, Chongqing, China
| | - Zhi-Fu Shen
- Department of Traditional Chinese and Western Medicine, North Sichuan Medical College, Nanchong, China
| | - Wei Wei
- Chengdu Xinan Gynecological Hospital, Chengdu, China
| | - Xiao-Li Guo
- Chengdu Xinan Gynecological Hospital, Chengdu, China
| | - Ling Chen
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Meng-Hua Su
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Lu Yang
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Si-Yi Yu
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- *Correspondence: Si-Yi Yu,
| | - Jie Yang
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Chengdu Xinan Gynecological Hospital, Chengdu, China
- Jie Yang,
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47
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Placebo administration for dry eye disease: a level I evidence based systematic review and meta-analysis. Int J Clin Pharm 2022; 44:1087-1101. [PMID: 35939178 PMCID: PMC9618542 DOI: 10.1007/s11096-022-01439-y] [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: 12/04/2021] [Accepted: 06/04/2022] [Indexed: 12/05/2022]
Abstract
Background The efficacy of various common treatment options for dry eye disease (DED) has been investigated against placebo. However, the potential beneficial effect of placebo in the management of DED is still unclear. Aim This meta-analysis investigated the impact of placebo administration in DED in Ocular Surface Disease Index (OSDI), Schirmer I test (SIT), tear breakup time (TBUT), corneal staining, and complications. Method This meta-analysis and systematic review was conducted according to the 2020 PRISMA guidelines. In March 2022, Pubmed, Web of Science, Google Scholar, and Embase were accessed. All the randomised clinical trials which investigated any active treatment against a placebo control group were considered. The following data were extracted at baseline and at last follow-up: Ocular Surface Disease Index (OSDI), tear breakup time test (TBUT), Schirmer I test (SIT), corneal staining. Results Data from 56 studies (12,205 patients) were retrieved. Placebo administration is not effective in improving TBUT (P = 0.3), OSDI (P = 0.2), SIT (P = 0.1) and corneal staining (P = 0.1) from baseline to last follow-up. Active treatment led to a higher TBUT and SIT compared to placebo administration (P < 0.0001). The active treatment resulted in a lower OSDI compared to placebo administration (P = 0.0005). Five studies reported data on the corneal staining. No difference was found between placebo administration and active treatment (P = 0.8). Conclusion Placebo administration does not impact symptoms of DED and can be successfully employed to evaluate the efficacy of active treatments. Supplementary Information The online version contains supplementary material available at 10.1007/s11096-022-01439-y.
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48
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Aksu S, Şirin TC, Hasırcı Bayır BR, Ulukan Ç, Soyata AZ, Kurt A, Karamürsel S, Baykan B. Long-Term Prophylactic Transcranial Direct Current Stimulation Ameliorates Allodynia and Improves Clinical Outcomes in Individuals With Migraine. Neuromodulation 2022:S1094-7159(22)00759-0. [DOI: 10.1016/j.neurom.2022.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 04/27/2022] [Accepted: 06/28/2022] [Indexed: 10/15/2022]
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49
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Nguyen E, Smith KM, Cramer N, Holland RA, Bleimeister IH, Flores-Felix K, Silberberg H, Keller A, Le Pichon CE, Ross SE. Medullary kappa-opioid receptor neurons inhibit pain and itch through a descending circuit. Brain 2022; 145:2586-2601. [PMID: 35598161 PMCID: PMC9612802 DOI: 10.1093/brain/awac189] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/01/2022] [Accepted: 04/27/2022] [Indexed: 11/13/2022] Open
Abstract
In perilous and stressful situations, the ability to suppress pain can be critical for survival. The rostral ventromedial medulla contains neurons that robustly inhibit nocioception at the level of the spinal cord through a top-down modulatory pathway. Although much is known about the role of the rostral ventromedial medulla in the inhibition of pain, the precise ability to directly manipulate pain-inhibitory neurons in the rostral ventromedial medulla has never been achieved. We now expose a cellular circuit that inhibits nocioception and itch in mice. Through a combination of molecular, tracing and behavioural approaches, we found that rostral ventromedial medulla neurons containing the kappa-opioid receptor inhibit itch and nocioception. With chemogenetic inhibition, we uncovered that these neurons are required for stress-induced analgesia. Using intersectional chemogenetic and pharmacological approaches, we determined that rostral ventromedial medulla kappa-opioid receptor neurons inhibit nocioception and itch through a descending circuit. Lastly, we identified a dynorphinergic pathway arising from the periaqueductal grey that modulates nociception within the rostral ventromedial medulla. These discoveries highlight a distinct population of rostral ventromedial medulla neurons capable of broadly and robustly inhibiting itch and nocioception.
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Affiliation(s)
- Eileen Nguyen
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Kelly M Smith
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Nathan Cramer
- Department of Anatomy and Neurobiology, Program in Neuroscience, University of Maryland, School of Medicine, Baltimore, MD 21201, USA
| | - Ruby A Holland
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Isabel H Bleimeister
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Krystal Flores-Felix
- Department of Anatomy and Neurobiology, Program in Neuroscience, University of Maryland, School of Medicine, Baltimore, MD 21201, USA
| | - Hanna Silberberg
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Asaf Keller
- Department of Anatomy and Neurobiology, Program in Neuroscience, University of Maryland, School of Medicine, Baltimore, MD 21201, USA
| | - Claire E Le Pichon
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sarah E Ross
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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50
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Takasawa E, Abe M, Chikuda H, Hanakawa T. A computational model based on corticospinal functional MRI revealed asymmetrically organized motor corticospinal networks in humans. Commun Biol 2022; 5:664. [PMID: 35790815 PMCID: PMC9256686 DOI: 10.1038/s42003-022-03615-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 06/21/2022] [Indexed: 11/21/2022] Open
Abstract
Evolution of the direct, monosynaptic connection from the primary motor cortex to the spinal cord parallels acquisition of hand dexterity and lateralization of hand preference. In non-human mammals, the indirect, multi-synaptic connections between the bilateral primary motor cortices and the spinal cord also participates in controlling dexterous hand movement. However, it remains unknown how the direct and indirect corticospinal pathways work in concert to control unilateral hand movement with lateralized preference in humans. Here we demonstrated the asymmetric functional organization of the two corticospinal networks, by combining network modelling and simultaneous functional magnetic resonance imaging techniques of the brain and the spinal cord. Moreover, we also found that the degree of the involvement of the two corticospinal networks paralleled lateralization of hand preference. The present results pointed to the functionally lateralized motor nervous system that underlies the behavioral asymmetry of handedness in humans. MRI and network modelling reveal correlation between the degree of involvement of the two corticospinal networks and the lateralization of handedness in humans.
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Affiliation(s)
- Eiji Takasawa
- Department of Advanced Neuroimaging, Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, Tokyo, Japan.,Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Mitsunari Abe
- Department of Advanced Neuroimaging, Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, Tokyo, Japan.
| | - Hirotaka Chikuda
- Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Takashi Hanakawa
- Department of Advanced Neuroimaging, Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, Tokyo, Japan. .,Department of Integrated Neuroanatomy & Neuroimaging, Kyoto University Graduate School of Medicine, Kyoto, Japan.
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