1
|
Jin S, Cho HJ. Cerebral hemodynamics as biomarkers for neuropathic pain in rats: a longitudinal study using a spinal nerve ligation model. Pain 2024:00006396-990000000-00655. [PMID: 38985168 DOI: 10.1097/j.pain.0000000000003332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Accepted: 06/07/2024] [Indexed: 07/11/2024]
Abstract
ABSTRACT Neuropathic pain is one of the most challenging types of pain to diagnose and treat, a problem exacerbated by the lack of a quantitative biomarker. Recently, several clinical and preclinical studies have shown that neuropathic pain induces cerebral hemodynamic changes as a result of neuroplasticity in the brain. Our hypothesis in this study is that neuropathic pain leads to cerebral hemodynamic changes over postoperative time in a spinal nerve ligation (SNL) rat model, which has not been longitudinally explored previously. Furthermore, by identifying multiple regional hemodynamic features that are the most distinct between SNL and sham groups, where the sham group underwent only an incision without SNL, it may be possible to classify the SNL group regardless of when the onset of pain occurs. We investigate cerebral hemodynamic changes using dynamic susceptibility contrast magnetic resonance imaging in a rat model up to 28 days after ligating L5/L6 spinal nerves. We trained a linear support vector machine with relative cerebral blood volume data from different brain regions and found that the prediction model trained on the nucleus accumbens, motor cortex, pretectal area, and thalamus classified the SNL group and sham group at a 79.27% balanced accuracy, regardless of when the onset of pain occurred (SNL/sham: 60/45 data points). From the use of the SNL model without prior knowledge of the onset time of pain, the current findings highlight the potential of relative cerebral blood volume in the 4 highlighted brain regions as a biomarker for neuropathic pain.
Collapse
Affiliation(s)
- Seokha Jin
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | | |
Collapse
|
2
|
Badwy M, Baart SJ, Thio HB, Huygen FJPM, de Vos CC. Electrical neurostimulation for the treatment of chronic pruritus: A systematic review. Exp Dermatol 2021; 31:280-289. [PMID: 34637585 PMCID: PMC9299998 DOI: 10.1111/exd.14468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 07/06/2021] [Accepted: 09/30/2021] [Indexed: 11/30/2022]
Abstract
Approximately one fifth of the world population experiences continuous itch for 6 weeks or more during their life, that is chronic itch. It is diverse in its aetiologies, and it is notoriously hard to treat. Because itch and pain have largely overlapping pathophysiology and the demonstrated efficacy of neurostimulation in treatment of selected chronic pain conditions, we conducted a systematic review to investigate whether neurostimulation could be an effective treatment for chronic itch. We identified two randomized controlled trials and 17 open label studies or case reports investigating various neurostimulation modalities for the treatment of refractory itch of various aetiologies. Transcutaneous electrical nerve stimulation (TENS) was the most investigated modality (n = 17), and in the largest number of conditions. Other modalities were cutaneous field stimulation (n = 2), painscrambler (n = 1), transcranial direct current stimulation (n = 1) and peripheral nerve field stimulation (n = 1). Atopic dermatitis was the most studied condition (n = 5). Despite the large heterogeneity in used stimulation paradigms and outcome parameters, all studies reported a positive effect of at least one neurostimulation modality. Our review indicates that electrical neurostimulation could be considered for the treatment of refractory chronic itch of selected aetiologies, such as atopic dermatitis or burn pruritus. However, better understanding of the mechanisms of action of the neurostimulation modalities and regimens in various pruritic conditions is necessary.
Collapse
Affiliation(s)
- Moustafa Badwy
- Center for pain Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Sara J Baart
- Center for pain Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.,Department of Biostatistics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Hok B Thio
- Department of Dermatology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Frank J P M Huygen
- Center for pain Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Cecile C de Vos
- Center for pain Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| |
Collapse
|
3
|
Current Understanding of the Involvement of the Insular Cortex in Neuropathic Pain: A Narrative Review. Int J Mol Sci 2021; 22:ijms22052648. [PMID: 33808020 PMCID: PMC7961886 DOI: 10.3390/ijms22052648] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/03/2021] [Accepted: 03/04/2021] [Indexed: 12/22/2022] Open
Abstract
Neuropathic pain is difficult to cure and is often accompanied by emotional and psychological changes. Exploring the mechanisms underlying neuropathic pain will help to identify a better treatment for this condition. The insular cortex is an important information integration center. Numerous imaging studies have documented increased activity of the insular cortex in the presence of neuropathic pain; however, the specific role of this region remains controversial. Early studies suggested that the insular lobe is mainly involved in the processing of the emotional motivation dimension of pain. However, increasing evidence suggests that the role of the insular cortex is more complex and may even be related to the neural plasticity, cognitive evaluation, and psychosocial aspects of neuropathic pain. These effects contribute not only to the development of neuropathic pain, but also to its comorbidity with neuropsychiatric diseases. In this review, we summarize the changes that occur in the insular cortex in the presence of neuropathic pain and analgesia, as well as the molecular mechanisms that may underlie these conditions. We also discuss potential sex-based differences in these processes. Further exploration of the involvement of the insular lobe will contribute to the development of new pharmacotherapy and psychotherapy treatments for neuropathic pain.
Collapse
|
4
|
Bravo L, Llorca-Torralba M, Berrocoso E, Micó JA. Monoamines as Drug Targets in Chronic Pain: Focusing on Neuropathic Pain. Front Neurosci 2019; 13:1268. [PMID: 31942167 PMCID: PMC6951279 DOI: 10.3389/fnins.2019.01268] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 11/08/2019] [Indexed: 12/11/2022] Open
Abstract
Monoamines are involved in regulating the endogenous pain system and indeed, peripheral and central monoaminergic dysfunction has been demonstrated in certain types of pain, particularly in neuropathic pain. Accordingly, drugs that modulate the monaminergic system and that were originally designed to treat depression are now considered to be first line treatments for certain types of neuropathic pain (e.g., serotonin and noradrenaline (and also dopamine) reuptake inhibitors). The analgesia induced by these drugs seems to be mediated by inhibiting the reuptake of these monoamines, thereby reinforcing the descending inhibitory pain pathways. Hence, it is of particular interest to study the monoaminergic mechanisms involved in the development and maintenance of chronic pain. Other analgesic drugs may also be used in combination with monoamines to facilitate descending pain inhibition (e.g., gabapentinoids and opioids) and such combinations are often also used to alleviate certain types of chronic pain. By contrast, while NSAIDs are thought to influence the monoaminergic system, they just produce consistent analgesia in inflammatory pain. Thus, in this review we will provide preclinical and clinical evidence of the role of monoamines in the modulation of chronic pain, reviewing how this system is implicated in the analgesic mechanism of action of antidepressants, gabapentinoids, atypical opioids, NSAIDs and histaminergic drugs.
Collapse
Affiliation(s)
- Lidia Bravo
- Neuropsychopharmacology and Psychobiology Research Group, Department of Neuroscience, University of Cádiz, Cádiz, Spain
- Instituto de Investigación e Innovación Biomédica de Cádiz, INiBICA, Hospital Universitario Puerta del Mar, Cádiz, Spain
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Instituto de Salud Carlos III, Madrid, Spain
| | - Meritxell Llorca-Torralba
- Neuropsychopharmacology and Psychobiology Research Group, Department of Neuroscience, University of Cádiz, Cádiz, Spain
- Instituto de Investigación e Innovación Biomédica de Cádiz, INiBICA, Hospital Universitario Puerta del Mar, Cádiz, Spain
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Instituto de Salud Carlos III, Madrid, Spain
| | - Esther Berrocoso
- Instituto de Investigación e Innovación Biomédica de Cádiz, INiBICA, Hospital Universitario Puerta del Mar, Cádiz, Spain
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Instituto de Salud Carlos III, Madrid, Spain
- Neuropsychopharmacology and Psychobiology Research Group, Department of Psychology, University of Cádiz, Cádiz, Spain
| | - Juan Antonio Micó
- Neuropsychopharmacology and Psychobiology Research Group, Department of Neuroscience, University of Cádiz, Cádiz, Spain
- Instituto de Investigación e Innovación Biomédica de Cádiz, INiBICA, Hospital Universitario Puerta del Mar, Cádiz, Spain
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Instituto de Salud Carlos III, Madrid, Spain
- *Correspondence: Juan Antonio Micó,
| |
Collapse
|
5
|
Bravo L, Mico JA, Rey-Brea R, Camarena-Delgado C, Berrocoso E. Effect of DSP4 and desipramine in the sensorial and affective component of neuropathic pain in rats. Prog Neuropsychopharmacol Biol Psychiatry 2016; 70:57-67. [PMID: 27181607 DOI: 10.1016/j.pnpbp.2016.05.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 05/08/2016] [Accepted: 05/09/2016] [Indexed: 12/13/2022]
Abstract
Previous findings suggest that neuropathic pain induces characteristic changes in the noradrenergic system that may modify the sensorial and affective dimensions of pain. We raise the hypothesis that different drugs that manipulate the noradrenergic system can modify specific domains of pain. In the chronic constriction injury (CCI) model of neuropathic pain, the sensorial (von Frey and acetone tests) and the affective (place escape/avoidance paradigm) domains of pain were evaluated in rats 1 and 2weeks after administering the noradrenergic neurotoxin [N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine hydrochloride] (DSP4, 50mg/kg). In other animals, we evaluated the effect of enhancing noradrenergic tone in the 2weeks after injury by administering the antidepressant desipramine (10mg/kg/day, delivered by osmotic minipumps) during this period, a noradrenaline reuptake inhibitor. Moreover, the phosphorylation of the extracellular signal regulated kinases (p-ERK) in the anterior cingulate cortex (ACC) was also assessed. The ACC receives direct inputs from the main noradrenergic nucleus, the locus coeruleus, and ERK activation has been related with the expression of pain-related negative affect. These studies revealed that DSP4 almost depleted noradrenergic axons in the ACC and halved noradrenergic neurons in the locus coeruleus along with a decrease in the affective dimension and an increased of p-ERK in the ACC. However, it did not modify sensorial pain perception. By contrast, desipramine reduced pain hypersensitivity, while completely impeding the reduction of the affective pain dimension and without modifying the amount of p-ERK. Together results suggest that the noradrenergic system may regulate the sensorial and affective sphere of neuropathic pain independently.
Collapse
Affiliation(s)
- Lidia Bravo
- Neuropsychopharmacology & Psychobiology Research Group, University of Cádiz, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Instituto de Salud Carlos III, 28007 Madrid, Spain; Psychobiology Area, Department of Psychology, University of Cadiz, Spain
| | - Juan A Mico
- Neuropsychopharmacology & Psychobiology Research Group, University of Cádiz, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Instituto de Salud Carlos III, 28007 Madrid, Spain; Department of Neuroscience, University of Cádiz, Spain
| | - Raquel Rey-Brea
- Neuropsychopharmacology & Psychobiology Research Group, University of Cádiz, Spain
| | | | - Esther Berrocoso
- Neuropsychopharmacology & Psychobiology Research Group, University of Cádiz, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Instituto de Salud Carlos III, 28007 Madrid, Spain; Psychobiology Area, Department of Psychology, University of Cadiz, Spain.
| |
Collapse
|
6
|
Lin HC, Huang YH, Chao THH, Lin WY, Sun WZ, Yen CT. Gabapentin reverses central hypersensitivity and suppresses medial prefrontal cortical glucose metabolism in rats with neuropathic pain. Mol Pain 2014; 10:63. [PMID: 25253440 PMCID: PMC4182821 DOI: 10.1186/1744-8069-10-63] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 09/10/2014] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Gabapentin (GBP) is known to suppress neuropathic hypersensitivity of primary afferents and the spinal cord dorsal horn. However, its supra-spinal action sites are unclear. We identify the brain regions where GBP changes the brain glucose metabolic rate at the effective dose that alleviates mechanical allodynia using 18 F-fluorodeoxyglucose-positron emission tomography (FDG-PET) scanning. RESULTS Comparing the PET imaging data before and after the GBP treatment, the spared nerve injury-induced increases of glucose metabolism in the thalamus and cerebellar vermis were reversed, and a significant decrease occurred in glucose metabolism in the medial prefrontal cortex (mPFC), including the anterior cingulate cortex. GBP treatment also reversed post-SNI connectivity increases between limbic cortices and thalamus. CONCLUSIONS Our results indicate that GBP analgesic effect may be mediated by reversing central hypersensitivity, and suppressing mPFC, a crucial part of the cortical representation of pain, in the brain.
Collapse
Affiliation(s)
- Hsiao-Chun Lin
- />Department of Life Science, National Taiwan University, No 1, Section 4, Roosevelt Road, Taipei, 10617 Taiwan
| | - Yu-Hsin Huang
- />Department of Anesthesiology, National Taiwan University Hospital, Taipei, 10002 Taiwan
| | - Tzu-Hao Harry Chao
- />Department of Life Science, National Taiwan University, No 1, Section 4, Roosevelt Road, Taipei, 10617 Taiwan
| | - Wen-Ying Lin
- />Department of Life Science, National Taiwan University, No 1, Section 4, Roosevelt Road, Taipei, 10617 Taiwan
- />Department of Anesthesiology, National Taiwan University Hospital, Taipei, 10002 Taiwan
| | - Wei-Zen Sun
- />Department of Anesthesiology, National Taiwan University Hospital, Taipei, 10002 Taiwan
| | - Chen-Tung Yen
- />Department of Life Science, National Taiwan University, No 1, Section 4, Roosevelt Road, Taipei, 10617 Taiwan
| |
Collapse
|
7
|
Deng L, Guindon J. Muscarinic agonists in the treatment of neuropathic pain: a novel finding. Clin Exp Pharmacol Physiol 2013; 40:395-7. [DOI: 10.1111/1440-1681.12123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Josée Guindon
- Department of Psychological and Brain Sciences; Indiana University; Bloomington; IN; USA
| |
Collapse
|
8
|
Catechol-O-methyltransferase gene polymorphism and chronic human pain: a systematic review and meta-analysis. Pharmacogenet Genomics 2013; 22:673-91. [PMID: 22722321 DOI: 10.1097/fpc.0b013e3283560c46] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In human studies, low COMT (catechol-O-methyltransferase) activity has been associated with increased sensitivity to acute clinical preoperative or postoperative pain. We explored the association between the COMT genotype and three chronic pain conditions: migrainous headache, fibromyalgia, or chronic widespread pain and chronic musculoskeletal pain. Furthermore, we evaluated whether COMT genotype affects the efficacy of opioids in chronic pain. After a systematic literature review, we carried out meta-analyses on the three chronic pain conditions. The efficacy of opioids was evaluated using a systematic review only. The meta-analyses showed that fibromyalgia or chronic widespread pain is the only type of chronic pain that could be associated with the COMT single nucleotide polymorphism rs4680 (Val158Met). Met158, which results in the low-activity variant of COMT, is the risk allele. In chronic clinical pain, the effect of the COMT polymorphism depends on the pain condition. Low COMT activity is not associated with migrainous headache or chronic musculoskeletal pain conditions, but it may increase the risk for fibromyalgia or chronic widespread pain. Low COMT activity increases opioid receptors and enhances opioid analgesia and adverse effects in some cancer pains. Findings from animal studies that have utilized COMT inhibitors elucidate the mechanism behind these findings. In rodent pain models, COMT inhibitors are pronociceptive, except for neuropathic pain models, where nitecapone was found to be antiallodynic. The complex interplay between enhanced adrenergic and dopaminergic activity in different parts of the nociceptive system probably explains the complicated actions of low COMT activity.
Collapse
|
9
|
Farghaly HSM, Abdel-Zaher AO, Mostafa MG, Kotb HI. Comparative evaluation of the effect of tricyclic antidepressants on inducible nitric oxide synthase expression in neuropathic pain model. Nitric Oxide 2012; 27:88-94. [DOI: 10.1016/j.niox.2012.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2012] [Revised: 04/24/2012] [Accepted: 05/07/2012] [Indexed: 12/23/2022]
|
10
|
Thompson SJ, Bushnell MC. Rodent functional and anatomical imaging of pain. Neurosci Lett 2012; 520:131-9. [PMID: 22445887 DOI: 10.1016/j.neulet.2012.03.015] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 03/06/2012] [Accepted: 03/07/2012] [Indexed: 02/07/2023]
Abstract
Human brain imaging has provided much information about pain processing and pain modulation, but brain imaging in rodents can provide information not attainable in human studies. First, the short lifespan of rats and mice, as well as the ability to have homogenous genetics and environments, allows for longitudinal studies of the effects of chronic pain on the brain. Second, brain imaging in animals allows for the testing of central actions of novel pharmacological and nonpharmacological analgesics before they can be tested in humans. The two most commonly used brain imaging methods in rodents are magnetic resonance imaging (MRI) and positron emission tomography (PET). MRI provides better spatial and temporal resolution than PET, but PET allows for the imaging of neurotransmitters and non-neuronal cells, such as astrocytes, in addition to functional imaging. One problem with rodent brain imaging involves methods for keeping the subject still in the scanner. Both anesthetic agents and restraint techniques have potential confounds. Some PET methods allow for tracer uptake before the animal is anesthetized, but imaging a moving animal also has potential confounds. Despite the challenges associated with the various techniques, the 31 studies using either functional MRI or PET to image pain processing in rodents have yielded surprisingly consistent results, with brain regions commonly activated in human pain imaging studies (somatosensory cortex, cingulate cortex, thalamus) also being activated in the majority of these studies. Pharmacological imaging in rodents shows overlapping activation patterns with pain and opiate analgesics, similar to what is found in humans. Despite the many structural imaging studies in human chronic pain patients, only one study has been performed in rodents, but that study confirmed human findings of decreased cortical thickness associated with chronic pain. Future directions in rodent pain imaging include miniaturized PET for the freely moving animal, as well as new MRI techniques that enable ongoing chronic pain imaging.
Collapse
Affiliation(s)
- Scott J Thompson
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC H3A 2T5, Canada
| | | |
Collapse
|
11
|
Hache G, Coudore F, Gardier AM, Guiard BP. Monoaminergic Antidepressants in the Relief of Pain: Potential Therapeutic Utility of Triple Reuptake Inhibitors (TRIs). Pharmaceuticals (Basel) 2011. [PMCID: PMC4053958 DOI: 10.3390/ph4020285] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Over 75% of depressed patients suffer from painful symptoms predicting a greater severity and a less favorable outcome of depression. Imaging, anatomical and functional studies have demonstrated the existence of common brain structures, neuronal pathways and neurotransmitters in depression and pain. In particular, the ascending serotonergic and noradrenergic pathways originating from the raphe nuclei and the locus coeruleus; respectively, send projections to the limbic system. Such pathways control many of the psychological functions that are disturbed in depression and in the perception of pain. On the other hand, the descending pathways, from monoaminergic nuclei to the spinal cord, are specifically implicated in the inhibition of nociception providing rationale for the use of serotonin (5-HT) and/or norepinephrine (NE) reuptake inhibitors (SSRIs, NRIs, SNRIs), in the relief of pain. Compelling evidence suggests that dopamine (DA) is also involved in the pathophysiology and treatment of depression. Indeed, recent insights have demonstrated a central role for DA in analgesia through an action at both the spinal and suprasinal levels including brain regions such as the periaqueductal grey (PAG), the thalamus, the basal ganglia and the limbic system. In this context, dopaminergic antidepressants (i.e., containing dopaminergic activity), such as bupropion, nomifensine and more recently triple reuptake inhibitors (TRIs), might represent new promising therapeutic tools in the treatment of painful symptoms with depression. Nevertheless, whether the addition of the dopaminergic component produces more robust effects than single- or dual-acting agents, has yet to be demonstrated. This article reviews the main pathways regulating pain transmission in relation with the monoaminergic systems. It then focuses on the current knowledge regarding the in vivo pharmacological properties and mechanism of action of monoaminergic antidepressants including SSRIs, NRIs, SNRIs and TRIs. Finally, a synthesis of the preclinical studies supporting the efficacy of these antidepressants in analgesia is also addressed in order to highlight the relative contribution of 5-HT, NE and DA to nociception.
Collapse
Affiliation(s)
- Guillaume Hache
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: 011-331-46-83-53-61
| | | | | | | |
Collapse
|
12
|
CNS animal fMRI in pain and analgesia. Neurosci Biobehav Rev 2010; 35:1125-43. [PMID: 21126534 DOI: 10.1016/j.neubiorev.2010.11.005] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Revised: 11/22/2010] [Accepted: 11/23/2010] [Indexed: 11/22/2022]
Abstract
Animal imaging of brain systems offers exciting opportunities to better understand the neurobiology of pain and analgesia. Overall functional studies have lagged behind human studies as a result of technical issues including the use of anesthesia. Now that many of these issues have been overcome including the possibility of imaging awake animals, there are new opportunities to study whole brain systems neurobiology of acute and chronic pain as well as analgesic effects on brain systems de novo (using pharmacological MRI) or testing in animal models of pain. Understanding brain networks in these areas may provide new insights into translational science, and use neural networks as a "language of translation" between preclinical to clinical models. In this review we evaluate the role of functional and anatomical imaging in furthering our understanding in pain and analgesia.
Collapse
|
13
|
Barrot M, Yalcin I, Tessier LH, Freund-Mercier MJ. Antidepressant treatment of neuropathic pain: looking for the mechanism. FUTURE NEUROLOGY 2010. [DOI: 10.2217/fnl.09.82] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Neuropathic pain arises as a direct consequence of a lesion or disease affecting the somatosensory system. Among the recommended first-line treatments are antidepressant drugs – that is, molecules that were initially developed to treat other disorders of the nervous system. While their clinical efficacy against neuropathic pain was established more than 30 years ago, there is little information on the mechanism underlying their antidepressant action. However, understanding the therapeutic mechanism of these treatments could help to improve them, or even lead to new therapeutic approaches. In this article, we discuss the difficulties in conducting relevant preclinical research on neuropathic pain treatment with antidepressant drugs and we present the most recent findings on the putative mechanism, which highlight the role of β2-adrenoceptors and δ-opioid receptors.
Collapse
Affiliation(s)
- Michel Barrot
- Département Nociception & Douleur, Institut des Neurosciences Cellulaires & Intégratives, 21 rue René Descartes, 67084 Strasbourg Cedex, France
| | - Ipek Yalcin
- Institut des Neurosciences Cellulaires & Intégratives, Centre National de la Recherche Scientifique, Strasbourg, France
| | - Luc-Henri Tessier
- Institut des Neurosciences Cellulaires & Intégratives, Centre National de la Recherche Scientifique, Strasbourg, France
| | | |
Collapse
|
14
|
Shah TH, Moradimehr A. Review Article: Bupropion for the Treatment of Neuropathic Pain. Am J Hosp Palliat Care 2010; 27:333-6. [DOI: 10.1177/1049909110361229] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Neuropathic pain is a common problem in clinical practice, affecting patients physically, emotionally, financially, and socially. Current treatment includes antidepressants, antiepileptics, and opioid analgesics. Bupropion is a specific inhibitor of neuronal noradrenaline reuptake and a weak inhibitor of dopamine reuptake, which shows some promise in the treatment of neuropathic pain.
Collapse
Affiliation(s)
- Tanmay H. Shah
- East Tennessee State University, Quillen College of Medicine, Johnson City, TN, USA,
| | | |
Collapse
|
15
|
Abstract
Neuroimaging makes it possible to study pain processing beyond the peripheral nervous system, at the supraspinal level, in a safe, noninvasive way, without interfering with neurophysiological processes. In recent years, studies using brain imaging methods have contributed to our understanding of the mechanisms responsible for the development and maintenance of chronic pain. Moreover, neuroimaging shows promising results for analgesic drug development and in characterizing different types of pain, bringing us closer to development of mechanism-based diagnoses and treatments for the chronic pain patient.
Collapse
Affiliation(s)
- Karolina Wartolowska
- grid.4991.50000000419368948Centre for Functional Magnetic Resonance Imaging of the Brain, Department of Clinical Neurology, and Nuffield Department of Anaesthetics, University of Oxford, Oxford, England, OX3 9DU, UK
| | - Irene Tracey
- grid.4991.50000000419368948Centre for Functional Magnetic Resonance Imaging of the Brain, Department of Clinical Neurology, and Nuffield Department of Anaesthetics, University of Oxford, Oxford, England, OX3 9DU, UK
| |
Collapse
|
16
|
Sorkin LS, Yaksh TL. Behavioral models of pain states evoked by physical injury to the peripheral nerve. Neurotherapeutics 2009; 6:609-19. [PMID: 19789066 PMCID: PMC5084283 DOI: 10.1016/j.nurt.2009.07.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Accepted: 07/09/2009] [Indexed: 11/30/2022] Open
Abstract
Physical injury or compression of the root, dorsal root ganglion, or peripheral sensory axon leads to well-defined changes in biology and function. Behaviorally, humans report ongoing painful dysesthesias and aberrations in function, such that an otherwise innocuous stimulus will yield a pain report. These behavioral reports are believed to reflect the underlying changes in nerve function after injury, wherein increased spontaneous activity arises from the neuroma and dorsal root ganglion and spinal changes increase the response of spinal projection neurons. These pain states are distinct from those associated with tissue injury and pose particular problems in management. To provide for developing an understanding of the underlying mechanisms of these pain states and to promote development of therapeutic agents, preclinical models involving section, compression, and constriction of the peripheral nerve or compression of the dorsal root ganglion have been developed. These models give rise to behaviors, which parallel those observed in the human after nerve injury. The present review considers these models and their application.
Collapse
Affiliation(s)
- Linda S. Sorkin
- grid.266100.30000000121074242Department of Anesthesiology, University of California, San Diego, 9500 Gilman Dr., Mail Code 0818, 92093-0818 La Jolla, CA
| | - Tony L. Yaksh
- grid.266100.30000000121074242Department of Anesthesiology, University of California, San Diego, 9500 Gilman Dr., Mail Code 0818, 92093-0818 La Jolla, CA
| |
Collapse
|