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Cao J, Tu Y, Orr SP, Lang C, Park J, Vangel M, Chen L, Gollub R, Kong J. Analgesic Effects Evoked by Real and Imagined Acupuncture: A Neuroimaging Study. Cereb Cortex 2019; 29:3220-3231. [PMID: 30137262 PMCID: PMC7302519 DOI: 10.1093/cercor/bhy190] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 07/08/2018] [Accepted: 07/19/2018] [Indexed: 12/20/2022] Open
Abstract
Acupuncture can provide therapeutic analgesic benefits but is limited by its cost and scheduling difficulties. Guided imagery is a commonly used method for treating many disorders, such as chronic pain. The present study examined a novel intervention for pain relief that integrates acupuncture with imagery called video-guided acupuncture imagery treatment (VGAIT). A total of 27 healthy subjects were recruited for a crossover-design study that included 5 sessions administered in a randomized order (i.e., baseline and 4 different interventions). We investigated changes in pain threshold and fMRI signals modulated by: 1) VGAIT, watching a video of acupuncture previously administered on the participant's own body at baseline while imagining it being concurrently applied; 2) a VGAIT control condition, watching a video of a cotton swab touching the skin; 3) real acupuncture; and 4) sham acupuncture. Results demonstrated that real acupuncture and VGAIT significantly increased pain threshold compared with respective control groups. Imaging showed that real acupuncture produced greater activation of the insula compared with VGAIT. VGAIT produced greater deactivation at the rostral anterior cingulate cortex. Our findings demonstrate that VGAIT holds potential clinical value for pain management.
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Affiliation(s)
- Jin Cao
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
- School of Acupuncture Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Yiheng Tu
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Scott P Orr
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Courtney Lang
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Joel Park
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Mark Vangel
- Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Lucy Chen
- Department of Anesthesia, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Randy Gollub
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
- Martinos Brain Imaging Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Jian Kong
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
- Martinos Brain Imaging Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
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Slupe AM, Kirsch JR. Effects of anesthesia on cerebral blood flow, metabolism, and neuroprotection. J Cereb Blood Flow Metab 2018; 38:2192-2208. [PMID: 30009645 PMCID: PMC6282215 DOI: 10.1177/0271678x18789273] [Citation(s) in RCA: 160] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 06/11/2018] [Accepted: 06/25/2018] [Indexed: 12/12/2022]
Abstract
Administration of anesthetic agents fundamentally shifts the responsibility for maintenance of homeostasis from the patient and their intrinsic physiological regulatory mechanisms to the anesthesiologist. Continuous delivery of oxygen and nutrients to the brain is necessary to prevent irreversible injury and arises from a complex series of regulatory mechanisms that ensure uninterrupted cerebral blood flow. Our understanding of these regulatory mechanisms and the effects of anesthetics on them has been driven by the tireless work of pioneers in the field. It is of paramount importance that the anesthesiologist shares this understanding. Herein, we will review the physiological determinants of cerebral blood flow and how delivery of anesthesia impacts these processes.
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Affiliation(s)
- Andrew M Slupe
- Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR, USA
| | - Jeffrey R Kirsch
- Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR, USA
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Zeidan F, Vago DR. Mindfulness meditation-based pain relief: a mechanistic account. Ann N Y Acad Sci 2017; 1373:114-27. [PMID: 27398643 DOI: 10.1111/nyas.13153] [Citation(s) in RCA: 131] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 05/25/2016] [Accepted: 05/25/2016] [Indexed: 12/15/2022]
Abstract
Pain is a multidimensional experience that involves interacting sensory, cognitive, and affective factors, rendering the treatment of chronic pain challenging and financially burdensome. Further, the widespread use of opioids to treat chronic pain has led to an opioid epidemic characterized by exponential growth in opioid misuse and addiction. The staggering statistics related to opioid use highlight the importance of developing, testing, and validating fast-acting nonpharmacological approaches to treat pain. Mindfulness meditation is a technique that has been found to significantly reduce pain in experimental and clinical settings. The present review delineates findings from recent studies demonstrating that mindfulness meditation significantly attenuates pain through multiple, unique mechanisms-an important consideration for the millions of chronic pain patients seeking narcotic-free, self-facilitated pain therapy.
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Affiliation(s)
- Fadel Zeidan
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, Winston-Salem, North Carolina
| | - David R Vago
- Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
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Moore K, Madularu D, Iriah S, Yee JR, Kulkarni P, Darcq E, Kieffer BL, Ferris CF. BOLD Imaging in Awake Wild-Type and Mu-Opioid Receptor Knock-Out Mice Reveals On-Target Activation Maps in Response to Oxycodone. Front Neurosci 2016; 10:471. [PMID: 27857679 PMCID: PMC5094148 DOI: 10.3389/fnins.2016.00471] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 10/03/2016] [Indexed: 02/06/2023] Open
Abstract
Blood oxygen level dependent (BOLD) imaging in awake mice was used to identify differences in brain activity between wild-type, and Mu (μ) opioid receptor knock-outs (MuKO) in response to oxycodone (OXY). Using a segmented, annotated MRI mouse atlas and computational analysis, patterns of integrated positive and negative BOLD activity were identified across 122 brain areas. The pattern of positive BOLD showed enhanced activation across the brain in WT mice within 15 min of intraperitoneal administration of 2.5 mg of OXY. BOLD activation was detected in 72 regions out of 122, and was most prominent in areas of high μ opioid receptor density (thalamus, ventral tegmental area, substantia nigra, caudate putamen, basal amygdala, and hypothalamus), and focus on pain circuits indicated strong activation in major pain processing centers (central amygdala, solitary tract, parabrachial area, insular cortex, gigantocellularis area, ventral thalamus primary sensory cortex, and prelimbic cortex). Importantly, the OXY-induced positive BOLD was eliminated in MuKO mice in most regions, with few exceptions (some cerebellar nuclei, CA3 of the hippocampus, medial amygdala, and preoptic areas). This result indicates that most effects of OXY on positive BOLD are mediated by the μ opioid receptor (on-target effects). OXY also caused an increase in negative BOLD in WT mice in few regions (16 out of 122) and, unlike the positive BOLD response the negative BOLD was only partially eliminated in the MuKO mice (cerebellum), and in some case intensified (hippocampus). Negative BOLD analysis therefore shows activation and deactivation events in the absence of the μ receptor for some areas where receptor expression is normally extremely low or absent (off-target effects). Together, our approach permits establishing opioid-induced BOLD activation maps in awake mice. In addition, comparison of WT and MuKO mutant mice reveals both on-target and off-target activation events, and set an OXY brain signature that should, in the future, be compared to other μ opioid agonists.
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Affiliation(s)
- Kelsey Moore
- Department of Psychology, Center for Translational NeuroImaging, Northeastern University Boston, MA, USA
| | - Dan Madularu
- Brain Imaging Center, Douglas Hospital Research Institute, McGill University Montreal, QC, Canada
| | - Sade Iriah
- Department of Psychology, Center for Translational NeuroImaging, Northeastern University Boston, MA, USA
| | - Jason R Yee
- Department of Psychology, Center for Translational NeuroImaging, Northeastern University Boston, MA, USA
| | - Praveen Kulkarni
- Department of Psychology, Center for Translational NeuroImaging, Northeastern University Boston, MA, USA
| | - Emmanuel Darcq
- Brain Imaging Center, Douglas Hospital Research Institute, McGill University Montreal, QC, Canada
| | - Brigitte L Kieffer
- Brain Imaging Center, Douglas Hospital Research Institute, McGill University Montreal, QC, Canada
| | - Craig F Ferris
- Department of Psychology, Center for Translational NeuroImaging, Northeastern University Boston, MA, USA
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Abstract
UNLABELLED Mindfulness meditation, a cognitive practice premised on sustaining nonjudgmental awareness of arising sensory events, reliably attenuates pain. Mindfulness meditation activates multiple brain regions that contain a high expression of opioid receptors. However, it is unknown whether mindfulness-meditation-based analgesia is mediated by endogenous opioids. The present double-blind, randomized study examined behavioral pain responses in healthy human volunteers during mindfulness meditation and a nonmanipulation control condition in response to noxious heat and intravenous administration of the opioid antagonist naloxone (0.15 mg/kg bolus + 0.1 mg/kg/h infusion) or saline placebo. Meditation during saline infusion significantly reduced pain intensity and unpleasantness ratings when compared to the control + saline group. However, naloxone infusion failed to reverse meditation-induced analgesia. There were no significant differences in pain intensity or pain unpleasantness reductions between the meditation + naloxone and the meditation + saline groups. Furthermore, mindfulness meditation during naloxone produced significantly greater reductions in pain intensity and unpleasantness than the control groups. These findings demonstrate that mindfulness meditation does not rely on endogenous opioidergic mechanisms to reduce pain. SIGNIFICANCE STATEMENT Endogenous opioids have been repeatedly shown to be involved in the cognitive inhibition of pain. Mindfulness meditation, a practice premised on directing nonjudgmental attention to arising sensory events, reduces pain by engaging mechanisms supporting the cognitive control of pain. However, it remains unknown if mindfulness-meditation-based analgesia is mediated by opioids, an important consideration for using meditation to treat chronic pain. To address this question, the present study examined pain reports during meditation in response to noxious heat and administration of the opioid antagonist naloxone and placebo saline. The results demonstrate that meditation-based pain relief does not require endogenous opioids. Therefore, the treatment of chronic pain may be more effective with meditation due to a lack of cross-tolerance with opiate-based medications.
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Postoperative Structural Brain Changes and Cognitive Dysfunction in Patients with Breast Cancer. PLoS One 2015; 10:e0140655. [PMID: 26536672 PMCID: PMC4633203 DOI: 10.1371/journal.pone.0140655] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 09/29/2015] [Indexed: 12/25/2022] Open
Abstract
Objective The primary purpose of this study was to clarify the influence of the early response to surgery on brain structure and cognitive function in patients with breast cancer. It was hypothesized that the structure of the thalamus would change during the early response after surgery due to the effects of anesthesia and would represent one aspect of an intermediate phenotype of postoperative cognitive dysfunction (POCD). Methods We examined 32 postmenopausal females with breast cancer and 20 age-matched controls. We assessed their cognitive function (attention, memory, and executive function), and performed brain structural MRI 1.5 ± 0.5 days before and 5.6 ± 1.2 days after surgery. Results We found a significant interaction between regional grey matter volume (rGMV) in the thalamus (P < 0.05, familywise error (FWE), small volume correction (SVC)) and one attention domain subtest (P = 0.001, Bonferroni correction) after surgery in the patient group compared with the control group. Furthermore, the changes in attention were significantly associated with sevoflurane anesthetic dose (r2 = 0.247, β = ‒0.471, P = 0.032) and marginally associated with rGMV changes in the thalamus (P = 0.07, FWE, SVC) in the Pt group. Conclusion Our findings suggest that alterations in brain structure, particularly in the thalamus, may occur shortly after surgery and may be associated with attentional dysfunction. This early postoperative response to anesthesia may represent an intermediate phenotype of POCD. It was assumed that patients experiencing other risk factors of POCD, such as the severity of surgery, the occurrence of complications, and pre-existing cognitive impairments, would develop clinical POCD with broad and multiple types of cognitive dysfunction.
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Wardle MC, Fitzgerald DA, Angstadt M, Rabinak CA, de Wit H, Phan KL. Effects of oxycodone on brain responses to emotional images. Psychopharmacology (Berl) 2014; 231:4403-15. [PMID: 24800897 PMCID: PMC6720110 DOI: 10.1007/s00213-014-3592-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 04/08/2014] [Indexed: 11/25/2022]
Abstract
RATIONALE Evidence from animal and human studies suggests that opiate drugs decrease emotional responses to negative stimuli and increase responses to positive stimuli. Such emotional effects may motivate misuse of oxycodone (OXY), a widely abused opiate. Yet, we know little about how OXY affects neural circuits underlying emotional processing in humans. OBJECTIVE We examined effects of OXY on brain activity during presentation of positive and negative visual emotional stimuli. We predicted that OXY would decrease amygdala activity to negative stimuli and increase ventral striatum (VS) activity to positive stimuli. Secondarily, we examined the effects of OXY on other emotional network regions on an exploratory basis. METHODS In a three-session study, healthy adults (N = 17) received placebo, 10 and 20 mg OXY under counterbalanced, double-blind conditions. At each session, participants completed subjective and cardiovascular measures and underwent functional MRI (fMRI) scanning while completing two emotional response tasks. RESULTS Our emotional tasks reliably activated emotional network areas. OXY produced subjective effects but did not alter either behavioral responses to emotional stimuli or activity in our primary areas of interest. OXY did decrease right medial orbitofrontal cortex (MOFC) responses to happy faces. CONCLUSIONS Contrary to our expectations, OXY did not affect behavioral or neural responses to emotional stimuli in our primary areas of interest. Further, the effects of OXY in the MOFC would be more consistent with a decrease in value for happy faces. This may indicate that healthy adults do not receive emotional benefits from opiates, or the pharmacological actions of OXY differ from other opiates.
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Affiliation(s)
- Margaret C. Wardle
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S. Maryland Ave., MC 3077, Chicago, IL 60637, USA
| | | | - Michael Angstadt
- Department of Psychiatry and Neuroscience Program, University of Michigan, Ann Arbor, MI, USA
| | - Christine A. Rabinak
- Department of Psychiatry and Neuroscience Program, University of Michigan, Ann Arbor, MI, USA
| | - Harriet de Wit
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S. Maryland Ave., MC 3077, Chicago, IL 60637, USA
| | - K. Luan Phan
- Mental Health Service Line, Jesse Brown VA Medical Center, Chicago, IL, USA
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Callan D, Mills L, Nott C, England R, England S. A tool for classifying individuals with chronic back pain: using multivariate pattern analysis with functional magnetic resonance imaging data. PLoS One 2014; 9:e98007. [PMID: 24905072 PMCID: PMC4048172 DOI: 10.1371/journal.pone.0098007] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 04/27/2014] [Indexed: 12/19/2022] Open
Abstract
Chronic pain is one of the most prevalent health problems in the world today, yet neurological markers, critical to diagnosis of chronic pain, are still largely unknown. The ability to objectively identify individuals with chronic pain using functional magnetic resonance imaging (fMRI) data is important for the advancement of diagnosis, treatment, and theoretical knowledge of brain processes associated with chronic pain. The purpose of our research is to investigate specific neurological markers that could be used to diagnose individuals experiencing chronic pain by using multivariate pattern analysis with fMRI data. We hypothesize that individuals with chronic pain have different patterns of brain activity in response to induced pain. This pattern can be used to classify the presence or absence of chronic pain. The fMRI experiment consisted of alternating 14 seconds of painful electric stimulation (applied to the lower back) with 14 seconds of rest. We analyzed contrast fMRI images in stimulation versus rest in pain-related brain regions to distinguish between the groups of participants: 1) chronic pain and 2) normal controls. We employed supervised machine learning techniques, specifically sparse logistic regression, to train a classifier based on these contrast images using a leave-one-out cross-validation procedure. We correctly classified 92.3% of the chronic pain group (N = 13) and 92.3% of the normal control group (N = 13) by recognizing multivariate patterns of activity in the somatosensory and inferior parietal cortex. This technique demonstrates that differences in the pattern of brain activity to induced pain can be used as a neurological marker to distinguish between individuals with and without chronic pain. Medical, legal and business professionals have recognized the importance of this research topic and of developing objective measures of chronic pain. This method of data analysis was very successful in correctly classifying each of the two groups.
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Affiliation(s)
- Daniel Callan
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Osaka University, Osaka, Japan
- Chronic Pain Diagnostics, Roseville, California, United States of America
| | - Lloyd Mills
- Chronic Pain Diagnostics, Roseville, California, United States of America
| | - Connie Nott
- Chronic Pain Diagnostics, Roseville, California, United States of America
| | - Robert England
- Chronic Pain Diagnostics, Roseville, California, United States of America
| | - Shaun England
- Chronic Pain Diagnostics, Roseville, California, United States of America
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Lee MC, Wanigasekera V, Tracey I. Imaging opioid analgesia in the human brain and its potential relevance for understanding opioid use in chronic pain. Neuropharmacology 2013; 84:123-30. [PMID: 23891639 PMCID: PMC4067746 DOI: 10.1016/j.neuropharm.2013.06.035] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 06/19/2013] [Accepted: 06/27/2013] [Indexed: 01/09/2023]
Abstract
Opioids play an important role for the management of acute pain and in palliative care. The role of long-term opioid therapy in chronic non-malignant pain remains unclear and is the focus of much clinical research. There are concerns regarding analgesic tolerance, paradoxical pain and issues with dependence that can occur with chronic opioid use in the susceptible patient. In this review, we discuss how far human neuroimaging research has come in providing a mechanistic understanding of pain relief provided by opioids, and suggest avenues for further studies that are relevant to the management of chronic pain with opioids. This article is part of the Special Issue Section entitled ‘Neuroimaging in Neuropharmacology’. Brain mechanisms are crucial to opioid analgesia in humans. Opioids can have a direct effect on brain mechanisms for pain perception. Opioids can also engage descending inhibition of spinal nociception. Drug-induced tolerance, dependence and paradoxical pain may limit chronic opioid analgesic therapy.
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Affiliation(s)
- Michael C Lee
- Centre for Functional MRI of the Brain (FMRIB), Department of Clinical Neurology and Nuffield Department of Clinical Neurosciences, Division of Anaesthesia, United Kingdom.
| | - Vishvarani Wanigasekera
- Centre for Functional MRI of the Brain (FMRIB), Department of Clinical Neurology and Nuffield Department of Clinical Neurosciences, Division of Anaesthesia, United Kingdom
| | - Irene Tracey
- Centre for Functional MRI of the Brain (FMRIB), Department of Clinical Neurology and Nuffield Department of Clinical Neurosciences, Division of Anaesthesia, United Kingdom.
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Duerden EG, Albanese MC. Localization of pain-related brain activation: a meta-analysis of neuroimaging data. Hum Brain Mapp 2011; 34:109-49. [PMID: 22131304 DOI: 10.1002/hbm.21416] [Citation(s) in RCA: 257] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 05/28/2011] [Accepted: 07/05/2011] [Indexed: 12/23/2022] Open
Abstract
A meta-analysis of 140 neuroimaging studies was performed using the activation-likelihood-estimate (ALE) method to explore the location and extent of activation in the brain in response to noxious stimuli in healthy volunteers. The first analysis involved the creation of a likelihood map illustrating brain activation common across studies using noxious stimuli. The left thalamus, right anterior cingulate cortex (ACC), bilateral anterior insulae, and left dorsal posterior insula had the highest likelihood of being activated. The second analysis contrasted noxious cold with noxious heat stimulation and revealed higher likelihood of activation to noxious cold in the subgenual ACC and the amygdala. The third analysis assessed the implications of using either a warm stimulus or a resting baseline as the control condition to reveal activation attributed to noxious heat. Comparing noxious heat to warm stimulation led to peak ALE values that were restricted to cortical regions with known nociceptive input. The fourth analysis tested for a hemispheric dominance in pain processing and showed the importance of the right hemisphere, with the strongest ALE peaks and clusters found in the right insula and ACC. The fifth analysis compared noxious muscle with cutaneous stimuli and the former type was more likely to evoke activation in the posterior and anterior cingulate cortices, precuneus, dorsolateral prefrontal cortex, and cerebellum. In general, results indicate that some brain regions such as the thalamus, insula and ACC have a significant likelihood of activation regardless of the type of noxious stimuli, while other brain regions show a stimulus-specific likelihood of being activated.
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Affiliation(s)
- Emma G Duerden
- Département de Physiologie, Groupe de Recherche Sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada.
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The response to rapid infusion of fentanyl in the human brain measured using pulsed arterial spin labelling. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2011; 25:163-75. [PMID: 22113518 DOI: 10.1007/s10334-011-0293-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Revised: 09/17/2011] [Accepted: 10/21/2011] [Indexed: 10/15/2022]
Abstract
OBJECTIVE We evaluated the sensitivity of pulsed Arterial Spin Labelling (pASL) for the detection of changes in regional cerebral blood perfusion (CBP) during and after intra-venous (i.v.) infusion of an opioid agonist (fentanyl) and an opioid antagonist (naloxone). MATERIALS AND METHODS Twenty-three subjects were scanned four times, receiving i.v. infusion of fentanyl, naloxone, placebo and a second fentanyl administration, in four separate scanning sessions in randomised order. End-tidal CO(2), respiration rate and heart rate were recorded continuously throughout each scan. pASL time series were collected using single shot EPI for 15 min (including 5 min of baseline prior to infusion). RESULTS Significant increases in CBP were detected during and after administration of fentanyl, (when compared to placebo and naloxone), in most areas of high concentration of mu-opioid receptors (thalamus, lingual gyrus, para-hippocampal gyrus, and insula); near-significant increases were also observed in the insula. No increases in perfusion were observed during or after naloxone infusion. No correlation was found between regional rCBF changes and end-tidal CO(2), respiration rate or heart rate. Good reliability was found between the first and second fentanyl sessions but the regions of high reliability did not overlap completely with those of highest perfusion change. CONCLUSION pASL is a suitable method for examining rapid, dynamic effects of opioid administration on brain physiology.
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[Studies on cerebral processing of pain using functional imaging : Somatosensory, emotional, cognitive, autonomic and motor aspects]. Schmerz 2010; 24:114-21. [PMID: 20376599 DOI: 10.1007/s00482-010-0896-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Functional neuroimaging methods such as positron emission tomography (PET) or functional magnetic resonance imaging (fMRI) provide fascinating insights into the cerebral processing of pain. Neuroimaging studies have shown that no clearly defined "pain centre" exists. Rather, an entire network of brain regions is involved in the processing of nociceptive information, which leads to the subjective impression of "pain". Sophisticated study designs nowadays permit the characterisation of different components of pain processing. In this review, we summarise neuroimaging studies, which contributed to the characterisation of these different aspects of cerebral pain processing, such as somatosensory (discrimination of different stimulus modalities, noxious vs non-noxious, summation), emotional, cognitive (attention, anticipation, distraction), vegetative (homeostasis) and motor aspects.
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Schoell ED, Bingel U, Eippert F, Yacubian J, Christiansen K, Andresen H, May A, Buechel C. The effect of opioid receptor blockade on the neural processing of thermal stimuli. PLoS One 2010; 5:e12344. [PMID: 20811582 PMCID: PMC2930255 DOI: 10.1371/journal.pone.0012344] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Accepted: 07/22/2010] [Indexed: 11/18/2022] Open
Abstract
The endogenous opioid system represents one of the principal systems in the modulation of pain. This has been demonstrated in studies of placebo analgesia and stress-induced analgesia, where anti-nociceptive activity triggered by pain itself or by cognitive states is blocked by opioid antagonists. The aim of this study was to characterize the effect of opioid receptor blockade on the physiological processing of painful thermal stimulation in the absence of cognitive manipulation. We therefore measured BOLD (blood oxygen level dependent) signal responses and intensity ratings to non-painful and painful thermal stimuli in a double-blind, cross-over design using the opioid receptor antagonist naloxone. On the behavioral level, we observed an increase in intensity ratings under naloxone due mainly to a difference in the non-painful stimuli. On the neural level, painful thermal stimulation was associated with a negative BOLD signal within the pregenual anterior cingulate cortex, and this deactivation was abolished by naloxone.
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Affiliation(s)
- Eszter D Schoell
- NeuroImage Nord, Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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Borsook D, Upadhyay J, Chudler EH, Becerra L. A key role of the basal ganglia in pain and analgesia--insights gained through human functional imaging. Mol Pain 2010; 6:27. [PMID: 20465845 PMCID: PMC2883978 DOI: 10.1186/1744-8069-6-27] [Citation(s) in RCA: 220] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Accepted: 05/13/2010] [Indexed: 01/18/2023] Open
Abstract
The basal ganglia (BG) are composed of several nuclei involved in neural processing related to the execution of motor, cognitive and emotional activities. Preclinical and clinical data have implicated a role for these structures in pain processing. Recently neuroimaging has added important information on BG activation in conditions of acute pain, chronic pain and as a result of drug effects. Our current understanding of alterations in cortical and sub-cortical regions in pain suggests that the BG are uniquely involved in thalamo-cortico-BG loops to integrate many aspects of pain. These include the integration of motor, emotional, autonomic and cognitive responses to pain.
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Affiliation(s)
- David Borsook
- PAIN Group, Harvard Medical School, 115 Mill Street, Belmont, MA 02478, USA.
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The spinothalamic system targets motor and sensory areas in the cerebral cortex of monkeys. J Neurosci 2009; 29:14223-35. [PMID: 19906970 DOI: 10.1523/jneurosci.3398-09.2009] [Citation(s) in RCA: 249] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Classically, the spinothalamic (ST) system has been viewed as the major pathway for transmitting nociceptive and thermoceptive information to the cerebral cortex. There is a long-standing controversy about the cortical targets of this system. We used anterograde transneuronal transport of the H129 strain of herpes simplex virus type 1 in the Cebus monkey to label the cortical areas that receive ST input. We found that the ST system reaches multiple cortical areas located in the contralateral hemisphere. The major targets are granular insular cortex, secondary somatosensory cortex and several cortical areas in the cingulate sulcus. It is noteworthy that comparable cortical regions in humans consistently display activation when subjects are acutely exposed to painful stimuli. We next combined anterograde transneuronal transport of virus with injections of a conventional tracer into the ventral premotor area (PMv). We used the PMv injection to identify the cingulate motor areas on the medial wall of the hemisphere. This combined approach demonstrated that each of the cingulate motor areas receives ST input. Our meta-analysis of imaging studies indicates that the human equivalents of the three cingulate motor areas also correspond to sites of pain-related activation. The cingulate motor areas in the monkey project directly to the primary motor cortex and to the spinal cord. Thus, the substrate exists for the ST system to have an important influence on the cortical control of movement.
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Pain-related effects of trait anger expression: neural substrates and the role of endogenous opioid mechanisms. Neurosci Biobehav Rev 2008; 33:475-91. [PMID: 19146872 DOI: 10.1016/j.neubiorev.2008.12.003] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Revised: 10/17/2008] [Accepted: 12/15/2008] [Indexed: 11/23/2022]
Abstract
Literature is reviewed indicating that greater tendency to manage anger via direct verbal or physical expression (trait anger-out) is associated with increased acute and chronic pain responsiveness. Neuroimaging data are overviewed supporting overlapping neural circuits underlying regulation of both pain and anger, consisting of brain regions including the rostral anterior cingulate cortex, orbitofrontal cortex, anterior insula, amygdala, and periaqueductal gray. These circuits provide a potential neural basis for observed positive associations between anger-out and pain responsiveness. The role of endogenous opioids in modulating activity in these interlinked brain regions is explored, and implications for understanding pain-related effects of anger-out are described. An opioid dysfunction hypothesis is presented in which inadequate endogenous opioid inhibitory activity in these brain regions contributes to links between trait anger-out and pain. A series of studies is presented that supports the opioid dysfunction hypothesis, further suggesting that gender and genetic factors may moderate these effects. Finally, possible implications of interactions between trait anger-out and state behavioral anger expression on endogenous opioid analgesic activity are described.
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Wang JY, Zhang HT, Chang JY, Woodward DJ, Baccalá LA, Luo F. Anticipation of pain enhances the nociceptive transmission and functional connectivity within pain network in rats. Mol Pain 2008; 4:34. [PMID: 18724875 PMCID: PMC2531182 DOI: 10.1186/1744-8069-4-34] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2008] [Accepted: 08/26/2008] [Indexed: 01/02/2023] Open
Abstract
Background Expectation is a very potent pain modulator in both humans and animals. There is evidence that pain transmission neurons are modulated by expectation preceding painful stimuli. Nonetheless, few studies have examined the influence of pain expectation on the pain-related neuronal activity and the functional connectivity within the central nociceptive network. Results This study used a tone-laser conditioning paradigm to establish the pain expectation in rats, and simultaneously recorded the anterior cingulate cortex (ACC), the medial dorsal thalamus (MD), and the primary somatosensory cortex (SI) to investigate the effect of pain expectation on laser-induced neuronal responses. Cross-correlation and partial directed coherence analysis were used to determine the functional interactions within and between the recorded areas during nociceptive transmission. The results showed that under anticipation condition, the neuronal activity to the auditory cue was significantly increased in the ACC area, whereas those to actual noxious stimuli were enhanced in all the recorded areas. Furthermore, neuronal correlations within and between these areas were significantly increased under conditions of expectation compared to those under non-expectation conditions, indicating an enhanced synchronization of neural activity within the pain network. In addition, information flow from the medial (ACC and MD) to the lateral (SI cortex) pain pathway increased, suggesting that the emotion-related neural circuits may modulate the neuronal activity in the somatosensory pathway during nociceptive transmission. Conclusion These results demonstrate that the nociceptive processing in both medial and lateral pain systems is modulated by the expectation of pain.
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Affiliation(s)
- Jin-Yan Wang
- Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, PR China.
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18
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Abstract
Rapidly developing, non-invasive, neuroimaging methods provide increasingly detailed structural and functional information about the nervous system, helping advance our understanding of pain processing, chronic pain conditions and the mechanisms of analgesia. However, effective treatment for many chronic pain conditions remains a large, unmet medical need. Neuroimaging techniques may enhance our understanding of why currently available analgesics are ineffective for so many patients and aid in identifying new neural targets for pharmacological interventions of pain. This review examines how neuroimaging has enhanced our understanding of the mechanisms of chronic pain, the neural correlates of pharmacological modulation of pain, and the role of neuroimaging in analgesic development. Rather than focusing on one method, we discuss the advantages and limitations of several techniques that may each serve a unique role in aiding drug development, and we discuss current issues that exist in the design and implementation of pharmacological neuroimaging studies. Particularly, experimental design must be carefully considered as there are limitations in terms of the pharmacokinetics of the drug of interest as well as in respect to the capabilities of the neuroimaging method in use. Finally, we identify future directions including novel approaches that may also play a role in furthering our knowledge of the neural basis of analgesia. In the future, neuroimaging will certainly impact the methodology of analgesic drug development as it may lead to quicker and more efficient methods of evaluating the neural modulation of chronic pain.
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Affiliation(s)
- Jane Lawrence
- Department of Anesthesia, Stanford University, Stanford, California 94304, USA
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19
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Galynker II, Eisenberg D, Matochik JA, Gertmenian-King E, Cohen L, Kimes AS, Contoreggi C, Kurian V, Ernst M, Rosenthal RN, Prosser J, London ED. Cerebral metabolism and mood in remitted opiate dependence. Drug Alcohol Depend 2007; 90:166-74. [PMID: 17521829 PMCID: PMC2063442 DOI: 10.1016/j.drugalcdep.2007.03.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2006] [Revised: 02/06/2007] [Accepted: 03/01/2007] [Indexed: 11/21/2022]
Abstract
BACKGROUND Opiate-dependent individuals are prone to dysphoria that may contribute to treatment failure. Methadone-maintenance therapy (MMT) may mitigate this vulnerability, but controversy surrounds its long-term use. Little is known about the neurobiology of mood dysregulation in individuals receiving or removed from MMT. METHODS Fifteen opiate-abstinent and 12 methadone-maintained, opiate-dependent subjects, who lacked other Axis I pathology, and 13 control subjects were compared on the Cornell Dysthymia Rating Scale (CDRS) and regional cerebral glucose metabolism (rCMRglc) using [(18)F]fluorodeoxyglucose positron emission tomography. RESULTS CDRS scores showed no group differences. Opiate-abstinent subjects had lower rCMRglc than control subjects in the bilateral perigenual anterior cingulate cortex (ACC), left mid-cingulate cortex, left insula and right superior frontal cortex. Methadone-maintained subjects exhibited lower rCMRglc than control subjects in the left insula and thalamus. In opiate-abstinent subjects, rCMRglc in the left perigenual ACC and mid-cingulate cortex correlated positively with CDRS scores. CONCLUSIONS In remitted heroin dependence, opiate-abstinence is associated with more widespread patterns of abnormal cortical activity than MMT. Aberrant mood processing in the left perigenual ACC and mid-cingulate cortex, seen in opiate-abstinent individuals, is absent in those receiving MMT, suggesting that methadone may improve mood regulation in this population.
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Affiliation(s)
- Igor I Galynker
- Department of Psychiatry and Behavioral Sciences, Beth Israel Medical Center, Albert Einstein College of Medicine, First Avenue at 16th Street, New York, NY 10003, USA.
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20
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Nemoto H, Nemoto Y, Toda H, Mikuni M, Fukuyama H. Placebo analgesia: a PET study. Exp Brain Res 2007; 179:655-64. [PMID: 17287994 DOI: 10.1007/s00221-006-0821-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2006] [Accepted: 11/29/2006] [Indexed: 11/25/2022]
Abstract
Placebo analgesia involves complex mechanisms and sometimes has a marked effect on patients in pain. In this study we examined changes in regional cerebral blood flow (rCBF) under three different conditions (resting, hot, painful) before and after placebo administration using H(2)(15)O and positron emission tomography in ten healthy subjects. In five subjects, placebo administration significantly decreased pain-intensity score (placebo responders), and rCBF in the medial prefrontal cortex (MPFC), posterior parietal cortex (PPC), and inferior parietal lobe (IPL) increased after placebo administration compared with before placebo administration under the painful condition. Furthermore, in the placebo responders, rCBF in the MPFC, PPC and IPL also increased under the resting condition (without sensory stimulation) after placebo administration compared with before placebo administration. However, there was no rCBF change under the rest condition in the placebo nonresponders after placebo administration. These results suggest that placebo analgesia has its effect under the resting condition and MPFC, IPL and PPC may have an important role in placebo analgesia.
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Affiliation(s)
- Hidenori Nemoto
- Department of Anesthesiology, Mito Red Cross Hospital, 3-12-48 Sannomaru, Mito, Ibaraki 310-0011, Japan.
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21
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Abstract
The discovery of the endogenous systems of analgesia has produced a large amount of research aimed at investigating their biochemical and neurophysiological mechanisms and their neuroanatomical localization. Nevertheless, the neurobiological acquisitions on these mechanisms have not been paralleled by behavioural correlates in humans--in other words, by the understanding of when and how these endogenous mechanisms of analgesia are activated. Until recent times one of the most studied behavioural correlates of endogenous analgesia was stress-induced analgesia, in which the activation of endogenous opioid systems is known to be involved. By contrast, today the placebo analgesic effect represents one of the best-described situations in which this endogenous opioid network is naturally activated in humans. Therefore, not only is placebo research helpful towards improving clinical trial design and medical practice, but it also provides us with a better understanding of the endogenous mechanisms of analgesia.
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Affiliation(s)
- F Benedetti
- Department of Neuroscience, Clinical and Applied Physiology Programme, University of Turin Medical School, Corso Raffaello 30, 10125 Turin, Italy.
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22
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Zubieta JK, Bueller JA, Jackson LR, Scott DJ, Xu Y, Koeppe RA, Nichols TE, Stohler CS. Placebo effects mediated by endogenous opioid activity on mu-opioid receptors. J Neurosci 2006; 25:7754-62. [PMID: 16120776 PMCID: PMC6725254 DOI: 10.1523/jneurosci.0439-05.2005] [Citation(s) in RCA: 619] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Reductions in pain ratings when administered a placebo with expected analgesic properties have been described and hypothesized to be mediated by the pain-suppressive endogenous opioid system. Using molecular imaging techniques, we directly examined the activity of the endogenous opioid system on mu-opioid receptors in humans in sustained pain with and without the administration of a placebo. Significant placebo-induced activation of mu-opioid receptor-mediated neurotransmission was observed in both higher-order and sub-cortical brain regions, which included the pregenual and subgenual rostral anterior cingulate, the dorsolateral prefrontal cortex, the insular cortex, and the nucleus accumbens. Regional activations were paralleled by lower ratings of pain intensity, reductions in its sensory and affective qualities, and in the negative emotional state of the volunteers. These data demonstrate that cognitive factors (e.g., expectation of pain relief) are capable of modulating physical and emotional states through the site-specific activation of mu-opioid receptor signaling in the human brain.
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Affiliation(s)
- Jon-Kar Zubieta
- Department of Psychiatry, Mental Health Research Institute, The University of Michigan, Ann Arbor, Michigan 48109-0720, USA.
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23
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Schlünzen L, Cold GE, Rasmussen M, Vafaee MS. Effects of dose-dependent levels of isoflurane on cerebral blood flow in healthy subjects studied using positron emission tomography. Acta Anaesthesiol Scand 2006; 50:306-12. [PMID: 16480463 DOI: 10.1111/j.1399-6576.2006.00954.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND In this study, we tested the hypothesis that escalating drug concentrations of isoflurane are associated with a significant decline in cerebral blood flow (CBF) in regions sub-serving conscious brain activity, including specifically the thalamus. METHODS Nine human volunteers received three escalating drug concentrations: 0.2, 0.4 and 1.0 MAC end-tidal inhalation. During waking, baseline and the three levels of sedation, aO PET scan was performed. RESULTS Isoflurane decreased the bispectral index (BIS) values dose-dependently. Cardiovascular and respiratory parameters were maintained constant over time. No significant change in global CBF was observed. Throughout all three MAC levels of sedation, isoflurane caused an increased regional cerebral blood flow (rCBF) in the anterior cingulate and decreased rCBF in the cerebellum. Initially, isoflurane (0 vs. 0.2 MAC) significantly increased relative rCBF in the medial frontal gyrus and in the nucleus accumbens. At the next level (0.2 vs. 0.4 MAC), relative rCBF was significantly increased in the caudate nucleus and decreased in the lingual gyrus and cuneus. At the last level (0.4 vs. 1 MAC), relative rCBF was significantly increased in the insula and decreased in the thalamus, the cuneus and lingual gyrus. Compared with flow distribution in awake volunteers, 1 MAC of isoflurane significantly raised relative activity in the anterior cingulate and insula regions. In contrast, a significant relative flow reduction was identified in the thalamus, the cerebellum and lingual gyrus. CONCLUSIONS Isoflurane, like sevoflurane, induced characteristic flow redistribution at doses of 0.2-1.0 MAC. At 1 MAC of isoflurane, rCBF decreased in the thalamus. Specific areas affected by both isoflurane and sevoflurane included the anterior cingulate, insula regions, cerebellum, lingual gyrus and thalamus.
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Affiliation(s)
- L Schlünzen
- Department of Neuroanaesthesiology, Aarhus University Hospital, Aarhus, Denmark.
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24
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Benedetti F, Mayberg HS, Wager TD, Stohler CS, Zubieta JK. Neurobiological mechanisms of the placebo effect. J Neurosci 2006; 25:10390-402. [PMID: 16280578 PMCID: PMC6725834 DOI: 10.1523/jneurosci.3458-05.2005] [Citation(s) in RCA: 437] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Fabrizio Benedetti
- Department of Neuroscience, University of Turin Medical School, 10125 Turin, Italy
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25
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Farrell MJ, Laird AR, Egan GF. Brain activity associated with painfully hot stimuli applied to the upper limb: a meta-analysis. Hum Brain Mapp 2005; 25:129-39. [PMID: 15846813 PMCID: PMC6871740 DOI: 10.1002/hbm.20125] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The capacity of pain to alert against potential injury or focus attention on damaged tissue is enhanced by the intrinsically aversive nature of the experience. Finding methods to relieve pain will ultimately be facilitated by deeper understanding of the processes that contribute to the experience, and functional brain imaging has contributed substantially toward that end. An impressive body of literature has identified a distributed network of pain-related activity in the brain that is subject to considerable modulation by different stimulus parameters, contextual factors, and clinical conditions. The fundamental substrates of the pain network are yet to be distilled from the highly variable results of studies published thus far. Qualitative reviews of the pain-imaging literature have been contributory, but lack the greater surety of quantitative methods. We employ the activation likelihood estimation (ALE) meta-analytic technique to establish the most consistent activations among studies reporting brain responses subsequent to the application of noxious heat. A network of pain-related activity was replicated for stimuli to either upper limb that included two discernible regions of the mid-anterior cingulate cortex, bilateral thalami, insula, and opercula cortices, posterior parietal cortex, premotor cortex, supplementary motor area, and cerebellum. The findings of the meta-analysis resonate with other streams of information that continue to enhance our understanding of pain in the brain. The results also point toward new areas of research that may be fruitful for the exploration of central pain processing.
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Affiliation(s)
- Michael J Farrell
- Howard Florey Institute, University of Melbourne, Melbourne, Australia.
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26
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Nagel E, Vilser W. Flicker observation light induces diameter response in retinal arterioles: a clinical methodological study. Br J Ophthalmol 2004; 88:54-6. [PMID: 14693773 PMCID: PMC1771962 DOI: 10.1136/bjo.88.1.54] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM To investigate diameter changes in retinal arterioles in response to flicker variations of the examination light. METHODS One randomised eye of five healthy subjects (mean age 33.8 (SD 1.6) years) was examined. The arterial diameter response to flicker light (12.5 Hz, 530-600 nm, duration 20 seconds) was automatically and continuously measured online three times by retinal vessel analyser (RVA) and once offline from flash images using the VesselMap program. RESULTS An arterial diameter response to flicker light was found both by RVA and by analysis of flash images (p<0.001). The maximum induced dilation reached at the end of the flicker period was +7.4% (SD 2.4%) in the RVA measurements and +3.5% (0.8%) in the photographs (p = 0.01). In both techniques the vascular diameter overshot the baseline approximately 10 seconds. In the RVA measurements a minimum of -4.6% (1.9%) (p = 0.01) was measured 22 (4.7) seconds after the end of flicker exposure. CONCLUSION Flicker evoked response for retinal arterioles was found both by RVA and by analysis of flash images. The authors believe that the method is suitable for the quantitative investigation of retinal vasosclerosis, especially in association with arteriosclerotic and hypertensive systemic disease.
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Affiliation(s)
- E Nagel
- Ophthalmic Private Practice, Anton-Sommer-Strasse 55, D-07407 Rudolstadt, Germany.
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27
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Borsook D, Becerra L. Pain imaging: future applications to integrative clinical and basic neurobiology. Adv Drug Deliv Rev 2003; 55:967-86. [PMID: 12935940 DOI: 10.1016/s0169-409x(03)00099-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We have entered a new era in understanding CNS circuitry involved in acute and chronic pain. The ability to objectively measure a pain or analgesic state of the brain using non-invasive methods that define neural activation provides the possibility for top-down approaches to drug discovery. These brain maps represent the specific brain state. In the future, correlations with such states and behavioral, genetic, epigenetic or other chemical markers may help define specific diagnostic tools and novel approaches to drug discovery.
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Affiliation(s)
- David Borsook
- Descartes Therapeutics, Inc, 790 Memorial Drive, Suite 104, Cambridge, MA, USA.
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28
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Treede RD. Pain and the Somatosensory Cortex. Pain 2003. [DOI: 10.1201/9780203911259.ch6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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29
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Reduction in opioid- and cannabinoid-induced antinociception in rhesus monkeys after bilateral lesions of the amygdaloid complex. J Neurosci 2001. [PMID: 11588195 DOI: 10.1523/jneurosci.21-20-08238.2001] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The amygdaloid complex is a prominent temporal lobe region that is associated with "emotional" information processing. Studies in the rodent have also recently implicated the amygdala in the processing and modulation of pain sensation, the experience of which involves a considerable emotional component in humans. In the present study, we sought to establish the relevance of the amygdala to pain modulation in humans by investigating the contribution of this region to antinociceptive processes in nonhuman primates. Using magnetic resonance imaging guidance, the amygdaloid complex was lesioned bilaterally in six rhesus monkeys (Macaca mulatta) through microinjection of the neurotoxin ibotenic acid. This procedure resulted in substantial neuronal cell loss in all nuclear subdivisions of this structure. In awake unoperated control monkeys, systemic administration of the prototypical opioid morphine or the cannabinoid receptor agonist WIN55,212-2 produced dose-dependent antinociception on a warm-water tail-withdrawal assay. The antinociceptive effects of each drug were reversible with an appropriate antagonist. In monkeys with bilateral amygdala lesions, however, the antinociceptive effects of each drug were significantly reduced. These results constitute the first causal data demonstrating the necessity of neurons in a specific brain region for the full expression of opioid- and cannabinoid-induced antinociception in the primate. Because our amygdala-lesioned monkeys exhibited both a reduction in antinociception and a reduction in behavioral indices of fear (Emery et al., 2001), the possibility should be considered that, in the primate, "antinociceptive circuitry" and "fear circuitry" overlap at the level of the amygdala.
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30
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Chung GH, Han YM, Kim CS. Functional MRI of the supplementary motor area: comparison of motor and sensory tasks. J Comput Assist Tomogr 2000; 24:521-5. [PMID: 10966180 DOI: 10.1097/00004728-200007000-00002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE The purpose of this work was to assess the activation of the supplementary motor area (SMA) during simple motor, complex motor, hot sensory, and touch sensory tasks. METHOD Functional MRI (fMRI) was performed in eight right-handed healthy volunteers. There were four tasks: simple motor, complex motor, hot sensory, and touch sensory. The number of pixels and the average percentage change of signal intensity in the activated SMA were obtained during the four tasks and then compared. RESULTS The SMA was consistently activated on fMRI during both motor and sensory tasks. The average number of activated pixels during the complex motor task was more than the number during the hot sensory task, but the difference was not statistically significant. The average number of activated pixels during the complex motor task was greater than during the simple motor task. The average number of activated pixels during the hot sensory task was greater than during the touch sensory task. The average percentage change of signal intensity was statistically significant between the simple motor and the complex motor task. The average percentage change of signal intensity was not statistically significant between the complex motor and the hot sensory task. CONCLUSION The SMA is activated in both motor and sensory tasks. The degree of activation of the SMA differs according to the type of task.
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Affiliation(s)
- G H Chung
- Department of Diagnostic Radiology, Chonbuk National University College of Medicine, Korea.
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31
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Bryant CA, Jackson SH. Functional imaging of the brain in the evaluation of drug response and its application to the study of aging. Drugs Aging 1998; 13:211-22. [PMID: 9789725 DOI: 10.2165/00002512-199813030-00004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Functional neuroimaging techniques including single photon emission computerised tomography (SPECT), positron emission tomography (PET) and functional magnetic resonance imaging (FMRI) can provide insight into the functional connectivity of the human brain in both health and disease, including the effects of aging and drugs on brain function. Neuroimaging measurement techniques can either be direct, using radio-specific ligands, or indirect, using the neurophysiological consequences of pharmacological interventions. Both approaches can be combined with sensorimotor or cognitive activation to examine the interaction between the targeted receptor function and the sensorimotor or cognitive process implicit in the study design. Using radionuclides, PET can provide absolute measurement of cerebral blood flow to regions of interest and can measure changes in cerebral metabolism using labelled fluorodeoxyglucose. PET offered the first opportunity to image brain activation caused by a variety of stimuli and hence to measure the effect of drugs on brain activation. PET also enables the study of drug disposition within the brain. SPECT has been used to study relative changes in cerebral blood flow associated with disease processes and also receptor occupancy. FMRI, by contrast, does not involve ionising radiation and has better spatial and temporal resolution. It is still a relatively new technique and limited by its ability to only measure haemodynamic changes through the blood oxygen level-dependent (BOLD) signal. The effects of aging on drug responsiveness and the effects of drug treatment of diseases associated with old age are relatively unexplored areas of functional neuroimaging research.
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Affiliation(s)
- C A Bryant
- Department of Health Care of the Elderly, King's College School of Medicine and Dentistry, London, England.
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