1
|
Tian X, Wang WT, Zhang MM, Yang QQ, Xu YL, Wu JB, Xie XX, Wang JY, Wang JY. Red nucleus mGluR1 and mGluR5 facilitate the development of neuropathic pain through stimulating the expressions of TNF-α and IL-1β. Neurochem Int 2024; 178:105786. [PMID: 38843952 DOI: 10.1016/j.neuint.2024.105786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Revised: 05/17/2024] [Accepted: 06/01/2024] [Indexed: 06/10/2024]
Abstract
Our previous study has identified that glutamate in the red nucleus (RN) facilitates the development of neuropathic pain through metabotropic glutamate receptors (mGluR). Here, we further explored the actions and possible molecular mechanisms of red nucleus mGluR Ⅰ (mGluR1 and mGluR5) in the development of neuropathic pain induced by spared nerve injury (SNI). Our data indicated that both mGluR1 and mGluR5 were constitutively expressed in the RN of normal rats. Two weeks after SNI, the expressions of mGluR1 and mGluR5 were significantly boosted in the RN contralateral to the nerve injury. Administration of mGluR1 antagonist LY367385 or mGluR5 antagonist MTEP to the RN contralateral to the nerve injury at 2 weeks post-SNI significantly ameliorated SNI-induced neuropathic pain. However, unilateral administration of mGluRⅠ agonist DHPG to the RN of normal rats provoked a significant mechanical allodynia, this effect could be blocked by LY367385 or MTEP. Further studies indicated that the expressions of TNF-α and IL-1β in the RN were also elevated at 2 weeks post-SNI. Administration of mGluR1 antagonist LY367385 or mGluR5 antagonist MTEP to the RN at 2 weeks post-SNI significantly inhibited the elevations of TNF-α and IL-1β. However, administration of mGluR Ⅰ agonist DHPG to the RN of normal rats significantly enhanced the expressions of TNF-α and IL-1β, these effects were blocked by LY367385 or MTEP. These results suggest that activation of red nucleus mGluR1 and mGluR5 facilitate the development of neuropathic pain by stimulating the expressions of TNF-α and IL-1β. mGluR Ⅰ maybe potential targets for drug development and clinical treatment of neuropathic pain.
Collapse
Affiliation(s)
- Xue Tian
- Department of Laboratory Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China; Department of Pathogenic Biology and Immunology, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, Shaanxi, China; Shaanxi Blood Center, Xi'an, 710061, Shaanxi, China
| | - Wen-Tao Wang
- Department of Pathogenic Biology and Immunology, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, Shaanxi, China
| | - Miao-Miao Zhang
- Department of Pathogenic Biology and Immunology, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, Shaanxi, China
| | - Qing-Qing Yang
- Department of Laboratory Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China; Department of Pathogenic Biology and Immunology, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, Shaanxi, China
| | - Ya-Li Xu
- Department of Pathogenic Biology and Immunology, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, Shaanxi, China
| | - Ji-Bo Wu
- Department of Pathogenic Biology and Immunology, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, Shaanxi, China
| | - Xin-Xin Xie
- Department of Pathogenic Biology and Immunology, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, Shaanxi, China
| | - Jun-Yang Wang
- Department of Pathogenic Biology and Immunology, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, Shaanxi, China.
| | - Jing-Yuan Wang
- Department of Laboratory Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China.
| |
Collapse
|
2
|
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
|
3
|
Wang L, Zhao S, Shao J, Su C. The effect and mechanism of low-dose esketamine in neuropathic pain-related depression-like behavior in rats. Brain Res 2024; 1843:149117. [PMID: 38977235 DOI: 10.1016/j.brainres.2024.149117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 05/28/2024] [Accepted: 07/05/2024] [Indexed: 07/10/2024]
Abstract
BACKGROUND Clinical evidence suggests that Esketamine (ESK) is an effective treatment for depression. However, the effects of Esketamine in treating depression-like behavior induced by neuropathic pain is unclear. The underlying molecular mechanisms require further investigation to provide new therapeutic targets for the treatment of clinical neuropathic pain-related depression. METHODS A neuropathic pain-related depression model was established in rats with spared nerve injury (SNI). Male Sprague-Dawley rats were randomly divided into four groups: Sham Group, SNI group, SNI + Normal Saline (NS) Group and SNI + ESK5mg/kg Group. Mechanical pain thresholds were measured to assess pain sensitivity in SNI rats. On the 14th day after surgery a forced swim test and sucrose preference test were used to evaluate the depressive-like behavior of rats in each group. Further, a proteomic analysis was used to quantify differentially expressed proteins. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were analyzed to explore the main protein targets of SNI in the medial prefrontal cortex. The expression of proteins was detected by Western blotting. RESULTS A neuropathic pain-related depression model was established. Compared with the Sham group, the mechanical pain threshold was decreased significantly (13.2 ± 1.0 vs. 0.7 ± 0.01 g n = 8), while immobility on the forced swim test was also decreased (93.1 ± 7.4 vs. 169.5 ± 9.6 s n = 8), and sucrose preference rate was significantly increased (98.8 ± 0.3 vs. 73.1 ± 1.4n = 7) in SNI group rats. Compared with the SNI + NS group, the mechanical pain threshold was not statistically significant, while immobility on the forced swim test was clearly decreased (161.1 ± 11.6 vs. 77.9 ± 5.0 s n = 8), and sucrose preference rate was significantly increased (53.1 ± 8.9 vs. 96.1 ± 1.4n = 7) in SNI + ESK5mg/kg group rats. To further investigate the underlying mechanism, we employed proteomics to identify proteins exhibiting more than a 1.2-fold difference (P < 0.05) in expression levels within each group for subsequent analysis. Relative to the Sham group, 88 downregulated and 104 up-regulated proteins were identified in the SNI group, while 120 and 84 proteins were up- and down-regulated in the Esketamine treatment group compared with the SNI + NS group. Compared with Sham group, the expressions of mGluR5 and Homer1a were up-regulated in the medial prefrontal cortex (mPFC) in SNI group (mGluR5:0.97 ± 0.05 vs 1.47 ± 0.15, Homer1a:1.03 ± 0.06 vs 1.46 ± 0.16n = 6), and down-regulated after intervention with Esketamine (mGluR5:1.54 ± 0.11 vs 1.06 ± 0.07, Homer1a:1.51 ± 0.13 vs 1.12 ± 0.34n = 6). CONCLUSIONS Low-dose Esketamine appeared to relieve depression-like behavior induced by neuropathic pain. The Homer1a-mGluR5 signaling pathway might be the mechanism of antidepressant effect of Esketamine.
Collapse
Affiliation(s)
- Lijuan Wang
- Department of Anesthesiology, The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University/ Hunan Cancer Hospital, Changsha, Hunan, China; Department of Medicine, Hengyang Medical School, University of South China, Hengyang, China
| | - Shuwu Zhao
- Department of Anesthesiology, The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University/ Hunan Cancer Hospital, Changsha, Hunan, China
| | - Jiali Shao
- Department of Anesthesiology, The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University/ Hunan Cancer Hospital, Changsha, Hunan, China
| | - Chen Su
- Department of Anesthesiology, The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University/ Hunan Cancer Hospital, Changsha, Hunan, China.
| |
Collapse
|
4
|
Fu S, Sun H, Wang J, Gao S, Zhu L, Cui K, Liu S, Qi X, Guan R, Fan X, Liu Q, Chen W, Su L, Cui S, Liao F, Liu F, Wong CCL, Yi M, Wan Y. Impaired neuronal macroautophagy in the prelimbic cortex contributes to comorbid anxiety-like behaviors in rats with chronic neuropathic pain. Autophagy 2024; 20:1559-1576. [PMID: 38522078 PMCID: PMC11210912 DOI: 10.1080/15548627.2024.2330038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 03/08/2024] [Indexed: 03/26/2024] Open
Abstract
A large proportion of patients with chronic pain experience co-morbid anxiety. The medial prefrontal cortex (mPFC) is proposed to underlie this comorbidity, but the molecular and neuronal mechanisms are not fully understood. Here, we reported that impaired neuronal macroautophagy in the prelimbic cortical (PrL) subregion of the mPFC paralleled the occurrence of anxiety-like behaviors in rats with chronic spared nerve injury (SNI). Intriguingly, such macroautophagy impairment was mainly observed in a FOS/c-Fos+ neuronal subpopulation in the PrL. Chemogenetic inactivation of this comorbid anxiety-related neuronal ensemble relieved pain-induced anxiety-like behaviors. Rescuing macroautophagy impairment in this neuronal ensemble relieved chronic pain-associated anxiety and mechanical allodynia and restored synaptic homeostasis at the molecular level. By contrast, artificial disruption of macroautophagy induced early-onset co-morbid anxiety in neuropathic rats, but not general anxiety in normal rats. Taken together, our work identifies causal linkage between PrL neuronal macroautophagy dysfunction and comorbid anxiety in neuropathic pain and provides novel insights into the role of PrL by differentiating its contribution in pain-induced comorbid anxiety from its modulation over general anxiety-like behaviors.Abbreviation: AAV: adeno-associated viruses; ACC: anterior cingulate cortex; ATG5: autophagy related 5; ATG7: autophagy related 7; ATG12: autophagy related 12; CAMK2/CaMKII: calcium/calmodulin-dependent protein kinase II; CNO: clozapine-N-oxide; CQ: chloroquine; DIA: data independent acquisition; DIO: double floxed inverse orf; DLG4/PSD-95: discs large MAGUK scaffold protein 4; Dox: doxycycline; GABA: γ-aminobutyric acid; GFP: green fluorescent protein; GO: gene ontology; Gi: inhibitory guanine nucleotide-binding proteins; HsCHRM4/M4D: human cholinergic receptor muscarinic 4; HsSYN: human synapsin; KEGG: Kyoto encyclopedia of genes and genomes; LAMP1: lysosomal-associated membrane protein 1; LC3-II: PE conjugated microtubule-associated protein 1 light chain3; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; mPFC: medial prefrontal cortex; P2A: 2A self-cleaving peptide; PPI: protein-protein interaction networks; PrL: prelimbic cortex; RBFOX3/NeuN: RNA binding protein, fox-1 homolog (C. elegans) 3; rtTA: reverse tetracycline-transactivator; SDS-PAGE: sodium dodecylsulfate-polyacrylamide gel electrophoresis; SHANK3: SH3 and multiple ankyrin repeat domains 3; SLC1A1/EAAC1: solute carrier family 1 (neuronal/epithelial high affinity glutamate transporter, systemXag), member 1; SNAP23: synaptosomal-associated protein 23; SNI:spared nerve injury; SQSTM1/p62: sequestosome 1; SYT3: synaptotagmin 3; TRE: tetracycline-responsive element; TRE3G: third-generation tetracycline-responsive element.
Collapse
Affiliation(s)
- Su Fu
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Haojie Sun
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, China
- Key Laboratory for Neuroscience, Ministry of Education and National Health Commission, Peking University, Beijing, China
- UCL School of Pharmacy, University College London, London, UK
| | - Jiaxin Wang
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, China
- Key Laboratory for Neuroscience, Ministry of Education and National Health Commission, Peking University, Beijing, China
| | - Shuaixin Gao
- Department of Medical Research Center, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing, China
- Human Nutrition Program, Department of Human Sciences & James Comprehensive Cancer Center, 309 Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA
| | - Liu Zhu
- Department of Biochemistry and Biophysics, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Kun Cui
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, China
- Key Laboratory for Neuroscience, Ministry of Education and National Health Commission, Peking University, Beijing, China
| | - Shimeng Liu
- Laboratory of Cardiovascular Bioactive Molecule, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Xuetao Qi
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, China
- Key Laboratory for Neuroscience, Ministry of Education and National Health Commission, Peking University, Beijing, China
| | - Rui Guan
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, China
- Key Laboratory for Neuroscience, Ministry of Education and National Health Commission, Peking University, Beijing, China
| | - Xiaocen Fan
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, China
- Key Laboratory for Neuroscience, Ministry of Education and National Health Commission, Peking University, Beijing, China
| | - Qingying Liu
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, China
- Key Laboratory for Neuroscience, Ministry of Education and National Health Commission, Peking University, Beijing, China
| | - Wen Chen
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, China
- Key Laboratory for Neuroscience, Ministry of Education and National Health Commission, Peking University, Beijing, China
| | - Li Su
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, China
- Key Laboratory for Neuroscience, Ministry of Education and National Health Commission, Peking University, Beijing, China
| | - Shuang Cui
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, China
- Key Laboratory for Neuroscience, Ministry of Education and National Health Commission, Peking University, Beijing, China
| | - Feifei Liao
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, China
- Key Laboratory for Neuroscience, Ministry of Education and National Health Commission, Peking University, Beijing, China
| | - Fengyu Liu
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, China
- Key Laboratory for Neuroscience, Ministry of Education and National Health Commission, Peking University, Beijing, China
| | - Catherine C L Wong
- Department of Medical Research Center, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing, China
| | - Ming Yi
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, China
- Key Laboratory for Neuroscience, Ministry of Education and National Health Commission, Peking University, Beijing, China
| | - You Wan
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, China
- Key Laboratory for Neuroscience, Ministry of Education and National Health Commission, Peking University, Beijing, China
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, P.R. China
| |
Collapse
|
5
|
Ebrahim Soltani Z, Elahi M, Askari Rad M, Farsio S, Dehpour AR. "Niclosamide: A potential antipruritic agent by modulating serotonin pathway through metabotropic glutamate receptors (mGluRs)". Heliyon 2024; 10:e33050. [PMID: 38994087 PMCID: PMC11238049 DOI: 10.1016/j.heliyon.2024.e33050] [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: 03/27/2024] [Revised: 06/08/2024] [Accepted: 06/13/2024] [Indexed: 07/13/2024] Open
Abstract
Pruritus is an uncomfortable sensation induced by various pruritogens, including serotonin. Serotonin, acting as an inflammatory mediator, can activate a histamine-independent pathway. Consequently, many anti-pruritus medications, such as antihistamines, are not effective in adequately relieving patient symptoms. Niclosamide, an anthelmintic drug, has recently demonstrated an affinity for Metabotropic glutamate receptors (mGluRs). mGluRs are a group of receptors activated by glutamate, and they are involved in regulating neuronal excitability. In this study, we utilized mouse models of serotonergic itch and administered different doses of Niclosamide to examine the expression of mGluR1, mGluR5, and 5-HT2. The administration of 5 mg/kg Niclosamide successfully suppressed pruritus in the mice. Additionally, the levels of mGluR1, mGluR5, 5-HT2, and TRPV1 were significantly reduced. These findings suggest that Niclosamide holds promise as a potential antipruritic drug.
Collapse
Affiliation(s)
- Zahra Ebrahim Soltani
- Experimental Medicine Research Center, Tehran University Medical Science, Tehran, Iran
| | - Mohammad Elahi
- Center for Orthopedic Trans-disciplinary Applied Research, Tehran University of Medical Science, Tehran, Iran
| | - Maziyar Askari Rad
- Pain Research Center, Neuroscience Institute, Imam Khomeini Hospital Complex, School of Medicine, Tehran University Medical Science, Tehran, Iran
| | - Sara Farsio
- Department of Microbiology, North Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Ahmad Reza Dehpour
- Experimental Medicine Research Center, Tehran University Medical Science, Tehran, Iran
| |
Collapse
|
6
|
Jahan M, Amir A, Das A, Kihlström J, Nag S. Automated radiosynthesis of mGluR5 PET tracer [ 18F]FPEB from aryl-chloro precursor and validation for clinical application. J Labelled Comp Radiopharm 2024; 67:155-164. [PMID: 38369901 DOI: 10.1002/jlcr.4088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 12/11/2023] [Accepted: 01/29/2024] [Indexed: 02/20/2024]
Abstract
The radioligand [18F]FPEB, used for PET imaging of the brain's metabotropic glutamate receptor subtype 5 (mGluR5), undergoes a thorough validation process to ensure its safety, efficacy, and quality for clinical use. The process starts by optimizing the synthesis of [18F]FPEB to achieve high radiochemical yield and purity. This study focuses on optimizing the radiolabeling process using an aryl-chloro precursor and validating the GMP production for clinical applications. Fully automated radiolabeling was achieved via one-step nucleophilic substitution reaction. [18F]FPEB was produced and isolated in high radioactivity and radiochemical purity. Throughout the validation process, thorough quality control measures are implemented. Radiopharmaceutical batch release criteria are established, including testing for physical appearance, filter integrity, pH, radiochemical purity, molar activity, radiochemical identity, chemical impurity, structural identity, stability, residual solvent, sterility, and endotoxin levels. In conclusion, the validation of [18F]FPEB involved a comprehensive process of synthesis optimization, quality control, which ensure the safety, efficacy, and quality of [18F]FPEB, enabling its reliable use in clinical PET. Here, we successfully radiolabeled and validated [18F]FPEB using aryl-chloro precursor according to GMP production for clinical application.
Collapse
Affiliation(s)
- Mahabuba Jahan
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Arsalan Amir
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Arindam Das
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Jacob Kihlström
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Sangram Nag
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| |
Collapse
|
7
|
PET imaging of animal models with depressive-like phenotypes. Eur J Nucl Med Mol Imaging 2023; 50:1564-1584. [PMID: 36642759 PMCID: PMC10119194 DOI: 10.1007/s00259-022-06073-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 12/03/2022] [Indexed: 01/17/2023]
Abstract
Major depressive disorder is a growing and poorly understood pathology. Due to technical and ethical limitations, a significant proportion of the research on depressive disorders cannot be performed on patients, but needs to be investigated in animal paradigms. Over the years, animal studies have provided new insight in the mechanisms underlying depression. Several of these studies have used PET imaging for the non-invasive and longitudinal investigation of the brain physiology. This review summarises the findings of preclinical PET imaging in different experimental paradigms of depression and compares these findings with observations from human studies. Preclinical PET studies in animal models of depression can be divided into three main different approaches: (a) investigation of glucose metabolism as a biomarker for regional and network involvement, (b) evaluation of the availability of different neuroreceptor populations associated with depressive phenotypes, and (c) monitoring of the inflammatory response in phenotypes of depression. This review also assesses the relevance of the use of PET imaging techniques in animal paradigms for the understanding of specific aspects of the depressive-like phenotypes, in particular whether it might contribute to achieve a more detailed characterisation of the clinical depressive phenotypes for the development of new therapies for depression.
Collapse
|
8
|
Zhou YP, Sun Y, Takahashi K, Belov V, Andrews N, Woolf CJ, Brugarolas P. Development of a PET radioligand for α2δ-1 subunit of calcium channels for imaging neuropathic pain. Eur J Med Chem 2022; 242:114688. [PMID: 36031695 PMCID: PMC9623503 DOI: 10.1016/j.ejmech.2022.114688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 08/11/2022] [Accepted: 08/12/2022] [Indexed: 11/26/2022]
Abstract
Neuropathic pain affects 7-10% of the adult population. Being able to accurately monitor biological changes underlying neuropathic pain will improve our understanding of neuropathic pain mechanisms and facilitate the development of novel therapeutics. Positron emission tomography (PET) is a noninvasive molecular imaging technique that can provide quantitative information of biochemical changes at the whole-body level by using radiolabeled ligands. One important biological change underlying the development of neuropathic pain is the overexpression of α2δ-1 subunit of voltage-dependent calcium channels (the target of gabapentin). Thus, we hypothesized that a radiolabeled form of gabapentin may allow imaging changes in α2δ-1 for monitoring the underlying pathophysiology of neuropathic pain. Here, we report the development of two 18F-labeled derivatives of gabapentin (trans-4-[18F]fluorogabapentin and cis-4-[18F]fluorogabapentin) and their evaluation in healthy rats and a rat model of neuropathic pain (spinal nerve ligation model). Both isomers were found to selectively bind to the α2δ-1 receptor with trans-4-[18F]fluorogabapentin having higher affinity. Both tracers displayed around 1.5- to 2-fold increased uptake in injured nerves over the contralateral uninjured nerves when measured by gamma counting ex vivo. Although the small size of the nerves and the signal from surrounding muscle prevented visualizing these changes using PET, this work demonstrates that fluorinated derivatives of gabapentin retain binding to α2δ-1 and that their radiolabeled forms can be used to detect pathological changes in vitro and ex vivo. Furthermore, this work confirms that α2δ-1 is a promising target for imaging specific features of neuropathic pain.
Collapse
Affiliation(s)
- Yu-Peng Zhou
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Yang Sun
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Kazue Takahashi
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Vasily Belov
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Nick Andrews
- F.M. Kirby Neurobiology Center, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Clifford J Woolf
- F.M. Kirby Neurobiology Center, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Pedro Brugarolas
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
9
|
Papadogiannis A, Dimitrov E. A Possible Mechanism for Development of Working Memory Impairment in Male Mice Subjected to Inflammatory Pain. Neuroscience 2022; 503:17-27. [PMID: 36100034 PMCID: PMC9588797 DOI: 10.1016/j.neuroscience.2022.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 08/30/2022] [Accepted: 09/05/2022] [Indexed: 11/15/2022]
Abstract
We studied the effects of inflammatory pain on working memory and correlated the pain effects with changes in dendritic spine density and glutamate signaling in the medial prefrontal cortex (mPFC) of male and female mice. Injection of Complete Freund's Adjuvant (CFA) into the hind paw modeled inflammatory pain. The CFA equally decreased the mechanical thresholds in both sexes. The density of dendritic spines, as a marker for neuronal input, increased on the dendrites of both, pyramidal cells and interneurons in males but only on the dendrites of interneurons in CFA injected females. Next, we injected virus with glutamate sensor (pAAV5.hSyn.iGluSnFr) into the mPFC and used fiber photometry to record glutamate signaling during Y-maze spontaneous alternations test, which is a test for working memory in rodents. The detected fluorescent signal was higher during correct alternations when compared to incorrect alternations in both sexes. The CFA injection did not change the pattern of glutamate fluorescence during the test but the female mice made fewer incorrect alternations than their male counterparts. Furthermore, while the CFA injection decreased the expression of the glutamate transporter VGlut1 on the soma of mPFC neurons in both sexes, the decrease was sex dependent. We concluded that inflammatory pain, which increases sensory input into the mPFC neurons, may impair working memory by altering the glutamate signaling. The glutamate deficit that develops as a result of the pain is more pronounced in male mice in comparison to female mice.
Collapse
Affiliation(s)
- Alexander Papadogiannis
- Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064, United States.
| | - Eugene Dimitrov
- Center for the Neurobiology of Stress Resilience and Psychiatric Disorders, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064, United States.
| |
Collapse
|
10
|
Pricope CV, Tamba BI, Stanciu GD, Cuciureanu M, Neagu AN, Creanga-Murariu I, Dobrovat BI, Uritu CM, Filipiuc SI, Pricope BM, Alexa-Stratulat T. The Roles of Imaging Biomarkers in the Management of Chronic Neuropathic Pain. Int J Mol Sci 2022; 23:13038. [PMID: 36361821 PMCID: PMC9657736 DOI: 10.3390/ijms232113038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/22/2022] [Accepted: 10/24/2022] [Indexed: 08/04/2023] Open
Abstract
Chronic neuropathic pain (CNP) affects around 10% of the general population and has a significant social, emotional, and economic impact. Current diagnosis techniques rely mainly on patient-reported outcomes and symptoms, which leads to significant diagnostic heterogeneity and subsequent challenges in management and assessment of outcomes. As such, it is necessary to review the approach to a pathology that occurs so frequently, with such burdensome and complex implications. Recent research has shown that imaging methods can detect subtle neuroplastic changes in the central and peripheral nervous system, which can be correlated with neuropathic symptoms and may serve as potential markers. The aim of this paper is to review available imaging methods used for diagnosing and assessing therapeutic efficacy in CNP for both the preclinical and clinical setting. Of course, further research is required to standardize and improve detection accuracy, but available data indicate that imaging is a valuable tool that can impact the management of CNP.
Collapse
Affiliation(s)
- Cosmin Vasilica Pricope
- Advanced Research and Development Center for Experimental Medicine (CEMEX), Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
- Department of Pharmacology, Clinical Pharmacology and Algesiology, Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
| | - Bogdan Ionel Tamba
- Advanced Research and Development Center for Experimental Medicine (CEMEX), Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
- Department of Pharmacology, Clinical Pharmacology and Algesiology, Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
| | - Gabriela Dumitrita Stanciu
- Advanced Research and Development Center for Experimental Medicine (CEMEX), Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
| | - Magdalena Cuciureanu
- Department of Pharmacology, Clinical Pharmacology and Algesiology, Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
| | - Anca Narcisa Neagu
- Laboratory of Animal Histology, Faculty of Biology, Alexandru Ioan Cuza University of Iasi, Carol I bvd. No. 22, 700505 Iasi, Romania
| | - Ioana Creanga-Murariu
- Advanced Research and Development Center for Experimental Medicine (CEMEX), Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
| | - Bogdan-Ionut Dobrovat
- Department of Radiology, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 16 University Street, 700115 Iasi, Romania
| | - Cristina Mariana Uritu
- Advanced Research and Development Center for Experimental Medicine (CEMEX), Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
| | - Silviu Iulian Filipiuc
- Advanced Research and Development Center for Experimental Medicine (CEMEX), Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
| | - Bianca-Mariana Pricope
- Department of Preventive Medicine and Interdisciplinarity, Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
| | - Teodora Alexa-Stratulat
- Advanced Research and Development Center for Experimental Medicine (CEMEX), Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
- Medical Oncology-Radiotherapy Department, Grigore T. Popa University of Medicine and Pharmacy, 16 University Street, 700115 Iasi, Romania
| |
Collapse
|
11
|
Yang HM, Hou TZ, Zhang YN, Zhao SD, Wu YL, Zhang H. Blocked metabotropic glutamate receptor 5 enhances chemosensitivity in hepatocellular carcinoma and attenuates chemotoxicity in the normal liver by regulating DNA damage. Cancer Gene Ther 2022; 29:1487-1501. [PMID: 35396501 DOI: 10.1038/s41417-022-00465-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 03/08/2022] [Accepted: 03/21/2022] [Indexed: 12/12/2022]
Abstract
DNA damaging agents are used as chemotherapeutics in many cancers, including hepatocellular carcinoma (HCC). However, they are associated with problems such as low sensitivity to chemotherapy and the induction of liver injury, underscoring the need to identify new therapies. Here, we investigated the differential regulatory effect of metabotropic glutamate receptor 5 (mGlu5) on chemosensitivity in HCC and chemotoxicity to the normal liver. The expression of mGlu5 was higher in HCC than in the normal liver, and correlated with poor prognosis according to The Cancer Genome Atlas database and Integrative Molecular Database of Hepatocellular Carcinoma. Cisplatin, oxaliplatin or methyl methanesulfonate (MMS) caused cell death by decreasing mGlu5 expression in HCC cells and increased mGlu5 expression in hepatic cells. In HCC cells, inhibition of mGlu5 aggravated MMS-induced DNA damage by increasing intracellular Ca2+ overload and mitogen-activated protein kinase (MAPK) activation, thereby promoting cell death, and activation of mGlu5 rescued the effect of MMS. However, in hepatic cells, mGlu5 inhibition alleviated MMS-induced DNA damage by downregulating Ca2+-derived MAPK pathways to advance hepatic cell survival. The opposite effects of mGlu5 overexpression or knockdown on MMS-induced DNA damage supported that cell death is a result of the differential regulation of mGlu5 expression. Inhibition of mGlu5 increased chemosensitivity and decreased chemotoxicity in a rat tumor model. This study suggests that mGlu5 inhibition could act synergistically with HCC chemotherapeutics with minimal side effects, which may improve the treatment of patients with HCC in the future.
Collapse
Affiliation(s)
- Hui-Min Yang
- Department of Neurobiology, School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Institute for Brain Disorders, Capital Medical University, 100069, Beijing, China
| | - Tian-Zhong Hou
- Department of Neurobiology, School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Institute for Brain Disorders, Capital Medical University, 100069, Beijing, China
| | - Ya-Nan Zhang
- Department of Neurobiology, School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Institute for Brain Disorders, Capital Medical University, 100069, Beijing, China
| | - Shu-Dong Zhao
- Department of Neurobiology, School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Institute for Brain Disorders, Capital Medical University, 100069, Beijing, China
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Engineering Medicine, Beihang University, 100083, Beijing, China
| | - Yong-Le Wu
- Center of Hepatic and Digestive Disease, Beijing YouAn Hospital, Capital Medical University, 100069, Beijing, China
| | - Hong Zhang
- Department of Neurobiology, School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Institute for Brain Disorders, Capital Medical University, 100069, Beijing, China.
| |
Collapse
|
12
|
Gao SH, Tao Y, Zhu Y, Huang H, Shen LL, Gao CY. Activation of Dopamine D2 Receptors Alleviates Neuronal Hyperexcitability in the Lateral Entorhinal Cortex via Inhibition of HCN Current in a Rat Model of Chronic Inflammatory Pain. Neurosci Bull 2022; 38:1041-1056. [PMID: 35705785 PMCID: PMC9468209 DOI: 10.1007/s12264-022-00892-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 04/10/2022] [Indexed: 10/18/2022] Open
Abstract
Functional changes in synaptic transmission from the lateral entorhinal cortex to the dentate gyrus (LEC-DG) are considered responsible for the chronification of pain. However, the underlying alterations in fan cells, which are the predominant neurons in the LEC that project to the DG, remain elusive. Here, we investigated possible mechanisms using a rat model of complete Freund's adjuvant (CFA)-induced inflammatory pain. We found a substantial increase in hyperpolarization-activated/cyclic nucleotide-gated currents (Ih), which led to the hyperexcitability of LEC fan cells of CFA slices. This phenomenon was attenuated in CFA slices by activating dopamine D2, but not D1, receptors. Chemogenetic activation of the ventral tegmental area -LEC projection had a D2 receptor-dependent analgesic effect. Intra-LEC microinjection of a D2 receptor agonist also suppressed CFA-induced behavioral hypersensitivity, and this effect was attenuated by pre-activation of the Ih. Our findings suggest that down-regulating the excitability of LEC fan cells through activation of the dopamine D2 receptor may be a strategy for treating chronic inflammatory pain.
Collapse
Affiliation(s)
- Shi-Hao Gao
- Department of Rehabilitation, Daping Hospital, Army Medical University, Chongqing, 400042, China
- Army 953 Hospital, Army Medical University, Shigatse, 857000, China
| | - Yong Tao
- Department of Rehabilitation, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Yang Zhu
- Department of Rehabilitation, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Hao Huang
- Department of Rehabilitation, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Lin-Lin Shen
- Department of Respiratory and Critical Care Medicine, Xinqiao Hospital, Army Medical University, Chongqing, 400037, China.
| | - Chang-Yue Gao
- Department of Rehabilitation, Daping Hospital, Army Medical University, Chongqing, 400042, China.
| |
Collapse
|
13
|
Hu Y, Zhu Y, Wen X, Zeng F, Feng Y, Xu Z, Xu F, Wang J. Repetitive transcranial magnetic stimulation regulates neuroinflammation, relieves hyperalgesia and reverses despair-like behaviour in chronic constriction injury rats. Eur J Neurosci 2022; 56:4930-4947. [PMID: 35895439 DOI: 10.1111/ejn.15779] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 07/08/2022] [Accepted: 07/16/2022] [Indexed: 11/28/2022]
Abstract
Repetitive transcranial magnetic stimulation (rTMS) could effectively relieve the pain and depression in neuropathic pain (NP) patients. However, the specific treatment parameters and exact mechanism are still unclear. Our purpose is to observe the effects of rTMS on pain and despair-like behaviour in chronic constriction injury (CCI) rats and explore its possible mechanism. Thirty-two 8-week-old male Sprague-Dawley rats were randomly divided into four groups: sham operation group (S, n = 8), CCI group (n = 8), 1 Hz-rTMS group (n = 8) and 10 Hz-rTMS group (n = 8). The rTMS was applied to the left dorsal anterior agranular insular (AId) 1 week after the operation, once a day, 5 days/week for 4 consecutive weeks. Mechanical hyperalgesia, despair-like behaviours and sciatic nerve function were used to evaluate the effects of rTMS. Besides, glucose metabolism, the metabotropic glutamate receptors 5 (mGluR5), N-Methyl-D-Aspartic acid receptor type 2B (NMDAR2B), tumour necrosis factor-α (TNF-α), interleukin-6 (Ll-6) and interleukin-1β (Ll-1β) in AId were tested to explore the possible mechanism. Compared with 1 Hz-rTMS, the rats of 10 Hz-rTMS had higher the mechanical hyperalgesia, higher sugar preference and shorter swimming immobility time. Besides, the expressions of mGluR5, NMDAR2B, TNF-α, Ll-1β and Ll-6 both in 1 Hz-rTMS and 10 Hz-rTMS groups were reduced compared with the CCI group; the 10 Hz-rTMS group had a more decrease than that of 1 Hz-rTMS. Furthermore, the [18]F-FDG uptake was lower than that in the 1 Hz-rTMS group. Compared with 1 Hz-rTMS, 10 Hz-rTMS could more effectively relieve mechanical hyperalgesia and reverse despair-like behaviour in rats. The mechanism could be related to regulating mGluR5/NMDAR2B-related inflammatory signalling pathways in the AId.
Collapse
Affiliation(s)
- Yue Hu
- Department of Rehabilitation Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Yuanliang Zhu
- Department of Rehabilitation Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Xin Wen
- Department of Rehabilitation Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Fanshuo Zeng
- Department of Rehabilitation Medicine, The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Yue Feng
- Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan Province, Luzhou, China
| | - Zhangyu Xu
- Department of Rehabilitation Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Fangyuan Xu
- Department of Rehabilitation Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Jianxiong Wang
- Department of Rehabilitation Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, China.,Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan Province, Luzhou, China.,Laboratory of Neurological Diseases and Brain Function, Luzhou, China
| |
Collapse
|
14
|
Mazzitelli M, Presto P, Antenucci N, Meltan S, Neugebauer V. Recent Advances in the Modulation of Pain by the Metabotropic Glutamate Receptors. Cells 2022; 11:2608. [PMID: 36010684 PMCID: PMC9406805 DOI: 10.3390/cells11162608] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/16/2022] [Accepted: 08/18/2022] [Indexed: 01/22/2023] Open
Abstract
Metabotropic glutamate receptors (mGluR or mGlu) are G-protein coupled receptors activated by the binding of glutamate, the main classical neurotransmitter of the nervous system. Eight different mGluR subtypes (mGluR1-8) have been cloned and are classified in three groups based on their molecular, pharmacological and signaling properties. mGluRs mediate several physiological functions such as neuronal excitability and synaptic plasticity, but they have also been implicated in numerous pathological conditions including pain. The availability of new and more selective allosteric modulators together with the canonical orthosteric ligands and transgenic technologies has led to significant advances in our knowledge about the role of the specific mGluR subtypes in the pathophysiological mechanisms of various diseases. Although development of successful compounds acting on mGluRs for clinical use has been scarce, the subtype-specific-pharmacological manipulation might be a compelling approach for the treatment of several disorders in humans, including pain; this review aims to summarize and update on preclinical evidence for the roles of different mGluRs in the pain system and discusses knowledge gaps regarding mGluR-related sex differences and neuroimmune signaling in pain.
Collapse
Affiliation(s)
- Mariacristina Mazzitelli
- Department of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Peyton Presto
- Department of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Nico Antenucci
- Department of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Shakira Meltan
- Department of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Volker Neugebauer
- Department of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
- Center of Excellence for Translational Neuroscience and Therapeutics, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
- Garrison Institute on Aging, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| |
Collapse
|
15
|
Metabotropic Glutamate Receptor 5 in the Dysgranular Zone of Primary Somatosensory Cortex Mediates Neuropathic Pain in Rats. Biomedicines 2022; 10:biomedicines10071633. [PMID: 35884938 PMCID: PMC9313034 DOI: 10.3390/biomedicines10071633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/05/2022] [Accepted: 07/06/2022] [Indexed: 11/16/2022] Open
Abstract
The primary somatosensory cortex (S1) plays a key role in the discrimination of somatic sensations. Among subdivisions in S1, the dysgranular zone of rodent S1 (S1DZ) is homologous to Brodmann’s area 3a of primate S1, which is involved in the processing of noxious signals from the body. However, molecular changes in this region and their role in the pathological pain state have never been studied. In this study, we identified molecular alteration of the S1DZ in a rat model of neuropathic pain induced by right L5 spinal nerve ligation (SNL) surgery and investigated its functional role in pain symptoms. Brain images acquired from SNL group and control group in our previous study were analyzed, and behaviors were measured using the von Frey test, acetone test, and conditioned place preference test. We found that metabotropic glutamate receptor 5 (mGluR5) levels were significantly upregulated in the S1DZ contralateral to the nerve injury in the SNL group compared to the sham group. Pharmacological deactivation of mGluR5 in S1DZ ameliorated symptoms of neuropathic allodynia, which was shown by a significant increase in the mechanical paw withdrawal threshold and a decrease in the behavioral response to cold stimuli. We further confirmed that this treatment induced relief from the tonic-aversive state of chronic neuropathic pain, as a place preference memory associated with the treatment-paired chamber was formed in rats with neuropathic pain. Our data provide evidence that mGluR5 in the S1DZ is involved in the manifestation of abnormal pain sensations in the neuropathic pain state.
Collapse
|
16
|
Zheng CJ, Van Drunen S, Egorova-Brumley N. Neural correlates of co-occurring pain and depression: an activation-likelihood estimation (ALE) meta-analysis and systematic review. Transl Psychiatry 2022; 12:196. [PMID: 35545623 PMCID: PMC9095719 DOI: 10.1038/s41398-022-01949-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 04/19/2022] [Accepted: 04/21/2022] [Indexed: 11/09/2022] Open
Abstract
The relationship between pain and depression is thought to be bidirectional and the underlying neurobiology 'shared' between the two conditions. However, these claims are often based on qualitative comparisons of brain regions implicated in pain or depression, while focused quantitative studies of the neurobiology of pain-depression comorbidity are lacking. Particularly, the direction of comorbidity, i.e., pain with depression vs. depression with pain, is rarely addressed. In this systematic review (PROSPERO registration CRD42020219876), we aimed to delineate brain correlates associated with primary pain with concomitant depression, primary depression with concurrent pain, and equal pain and depression comorbidity, using activation likelihood estimation (ALE) meta-analysis. Neuroimaging studies published in English until the 28th of September 2021 were evaluated using PRISMA guidelines. A total of 70 studies were included, of which 26 reported stereotactic coordinates and were analysed with ALE. All studies were assessed for quality by two authors, using the National Institute of Health Quality Assessment Tool. Our results revealed paucity of studies that directly investigated the neurobiology of pain-depression comorbidity. The ALE analysis indicated that pain with concomitant depression was associated with the right amygdala, while depression with concomitant pain was related primarily to the left dorsolateral prefrontal cortex (DLPFC). We provide evidence that pain and depression have a cumulative negative effect on a specific set of brain regions, distinct for primary diagnosis of depression vs. pain.
Collapse
Affiliation(s)
| | | | - Natalia Egorova-Brumley
- The University of Melbourne, Parkville, VIC, Australia.
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia.
| |
Collapse
|
17
|
Mills EP, Keay KA, Henderson LA. Brainstem Pain-Modulation Circuitry and Its Plasticity in Neuropathic Pain: Insights From Human Brain Imaging Investigations. FRONTIERS IN PAIN RESEARCH 2021; 2:705345. [PMID: 35295481 PMCID: PMC8915745 DOI: 10.3389/fpain.2021.705345] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 06/23/2021] [Indexed: 11/17/2022] Open
Abstract
Acute pain serves as a protective mechanism that alerts us to potential tissue damage and drives a behavioural response that removes us from danger. The neural circuitry critical for mounting this behavioural response is situated within the brainstem and is also crucial for producing analgesic and hyperalgesic responses. In particular, the periaqueductal grey, rostral ventromedial medulla, locus coeruleus and subnucleus reticularis dorsalis are important structures that directly or indirectly modulate nociceptive transmission at the primary nociceptive synapse. Substantial evidence from experimental animal studies suggests that plasticity within this system contributes to the initiation and/or maintenance of chronic neuropathic pain, and may even predispose individuals to developing chronic pain. Indeed, overwhelming evidence indicates that plasticity within this circuitry favours pro-nociception at the primary synapse in neuropathic pain conditions, a process that ultimately contributes to a hyperalgesic state. Although experimental animal investigations have been crucial in our understanding of the anatomy and function of the brainstem pain-modulation circuitry, it is vital to understand this system in acute and chronic pain states in humans so that more effective treatments can be developed. Recent functional MRI studies have identified a key role of this system during various analgesic and hyperalgesic responses including placebo analgesia, offset analgesia, attentional analgesia, conditioned pain modulation, central sensitisation and temporal summation. Moreover, recent MRI investigations have begun to explore brainstem pain-modulation circuitry plasticity in chronic neuropathic pain conditions and have identified altered grey matter volumes and functioning throughout the circuitry. Considering the findings from animal investigations, it is likely that these changes reflect a shift towards pro-nociception that ultimately contributes to the maintenance of neuropathic pain. The purpose of this review is to provide an overview of the human brain imaging investigations that have improved our understanding of the pain-modulation system in acute pain states and in neuropathic conditions. Our interpretation of the findings from these studies is often guided by the existing body of experimental animal literature, in addition to evidence from psychophysical investigations. Overall, understanding the plasticity of this system in human neuropathic pain conditions alongside the existing experimental animal literature will ultimately improve treatment options.
Collapse
|
18
|
Xu X, Wu K, Ma X, Wang W, Wang H, Huang M, Luo L, Su C, Yuan T, Shi H, Han J, Wang A, Xu T. mGluR5-Mediated eCB Signaling in the Nucleus Accumbens Controls Vulnerability to Depressive-Like Behaviors and Pain After Chronic Social Defeat Stress. Mol Neurobiol 2021; 58:4944-4958. [PMID: 34227060 DOI: 10.1007/s12035-021-02469-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/21/2021] [Indexed: 12/16/2022]
Abstract
Stress contributes to major depressive disorder (MDD) and chronic pain, which affect a significant portion of the global population, but researchers have not clearly determined how these conditions are initiated or amplified by stress. The chronic social defeat stress (CSDS) model is a mouse model of psychosocial stress that exhibits depressive-like behavior and chronic pain. We hypothesized that metabotropic glutamate receptor 5 (mGluR5) expressed in the nucleus accumbens (NAc) normalizes the depressive-like behaviors and pain following CSDS. Here, we show that CSDS induced both pain and social avoidance and that the level of mGluR5 decreased in susceptible mice. Overexpression of mGluR5 in the NAc shell and core prevented the development of depressive-like behaviors and pain in susceptible mice, respectively. Conversely, depression-like behaviors and pain were exacerbated in mice with mGluR5 knockdown in the NAc shell and core, respectively, compared to control mice subjected to 3 days of social defeat stress. Furthermore, (RS)-2-chloro-5-hydroxyphenylglycine (CHPG), an mGluR5 agonist, reversed the reduction in the level of the endocannabinoid (eCB) 2-arachidonoylglycerol (2-AG) in the NAc of susceptible mice, an effect that was blocked by 3-((2-methyl-1, 3-thiazol-4-yl) ethynyl) pyridine hydrochloride (MTEP), an mGluR5 antagonist. In addition, the injection of CHPG into the NAc shell and core normalized depressive-like behaviors and pain, respectively, and these effects were inhibited by AM251, a cannabinoid type 1 receptor (CB1R) antagonist. Based on these results, mGluR5-mediated eCB production in the NAc relieves stress-induced depressive-like behaviors and pain.
Collapse
Affiliation(s)
- Xiaotao Xu
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, People's Republic of China
| | - Kaixuan Wu
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, People's Republic of China
| | - Xiaqing Ma
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, People's Republic of China
| | - Wenying Wang
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, People's Republic of China
| | - Haiyan Wang
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, People's Republic of China
| | - Min Huang
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, People's Republic of China
| | - Limin Luo
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, People's Republic of China
| | - Chen Su
- Department of Anesthesiology and Pain Medicine, Hunan Cancer Hospital/The Affiliated Cancer Hospital of Xiangya School of Medicine, Changsha, 410013, People's Republic of China
| | - Tifei Yuan
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200030, People's Republic of China
| | - Haibo Shi
- Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, 200233, People's Republic of China
| | - Ji Han
- Internal medicine of TCM, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, No.164 Lanxi Road, Shanghai, 200062, China.
| | - Aizhong Wang
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, People's Republic of China.
| | - Tao Xu
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, People's Republic of China. .,Department of Anesthesiology, Tongzhou People's Hospital, Nantong, 226300, China.
| |
Collapse
|
19
|
Medeiros P, Dos Santos IR, Júnior IM, Palazzo E, da Silva JA, Machado HR, Ferreira SH, Maione S, Coimbra NC, de Freitas RL. An Adapted Chronic Constriction Injury of the Sciatic Nerve Produces Sensory, Affective, and Cognitive Impairments: A Peripheral Mononeuropathy Model for the Study of Comorbid Neuropsychiatric Disorders Associated with Neuropathic Pain in Rats. PAIN MEDICINE 2021; 22:338-351. [PMID: 32875331 DOI: 10.1093/pm/pnaa206] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Chronic constriction injury (CCI) is a model of neuropathic pain induced by four loose ligatures around the sciatic nerve. This work aimed to investigate the sensory, affective, cognitive, and motor changes induced by an adaptation of the CCI model by applying a single ligature around the sciatic nerve. METHODS Mechanical allodynia was measured from day 1 to day 28 postsurgery by the von Frey test. The beam walking test (BWT) was conducted weekly until 28 days after surgery. Anxiety- and depression-like behaviors, and cognitive performance were assessed through the open field (OF), forced swimming (FS), and novel object recognition (NOR) tests, respectively, 21 days after surgery. RESULTS The two CCI models, both Bennett and Xie's model (four ligatures of the sciatic nerve) and a modification of it (one ligature), induced mechanical allodynia, increased immobility in the FS, and reduced recognition index in the NOR. The exploratory behavior and time spent in the central part of the arena decreased, while the defensive behavior increased in the OF. The animals subjected to the two CCI models showed motor alterations in the BWT; however, autotomy was observed only in the group with four ligatures and not in the group with a single ligature. CONCLUSIONS Overall these results demonstrate that our adapted CCI model, using a single ligature around the sciatic nerve, induces sensory, affective, cognitive, and motor alterations comparable to the CCI model with four ligatures without generating autotomy. This adaptation to the CCI model may therefore represent an appropriate and more easily performed model for inducing neuropathic pain and study underlying mechanisms and effective treatments.
Collapse
Affiliation(s)
- Priscila Medeiros
- Laboratory of Neurosciences of Pain & Emotions and Neuroelectrophysiology Multi-User Centre, Department of Surgery and Anatomy, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Ribeirão Preto, São Paulo, Brazil.,Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Ribeirão Preto, São Paulo, Brazil.,Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Ieda Regina Dos Santos
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Ribeirão Preto, São Paulo, Brazil
| | - Ivair Matias Júnior
- Laboratory of Pediatric Surgery, Department of Surgery and Anatomy, Ribeirão Preto Medical School of the University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Enza Palazzo
- Division of Pharmacology, Department of Experimental Medicine, University of Campania "L. Vanvitelli," Naples, Italy
| | - José Aparecido da Silva
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Ribeirão Preto, São Paulo, Brazil.,Department of Psychology, Ribeirão Preto School of Philosophy, Sciences and Literature of the University of São Paulo, Ribeirão Preto, São Paulo, Brazil.,Psychology Department, Federal University of Juiz de Fora (UFJF-MG), Juiz de Fora, Minas Gerais, Brazil
| | - Hélio Rubens Machado
- Laboratory of Neurosciences of Pain & Emotions and Neuroelectrophysiology Multi-User Centre, Department of Surgery and Anatomy, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Ribeirão Preto, São Paulo, Brazil.,Laboratory of Pediatric Surgery, Department of Surgery and Anatomy, Ribeirão Preto Medical School of the University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Sérgio Henrique Ferreira
- Laboratory of Neurosciences of Pain & Emotions and Neuroelectrophysiology Multi-User Centre, Department of Surgery and Anatomy, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Ribeirão Preto, São Paulo, Brazil.,Biomedical Sciences Institute, Federal University of Alfenas (UNIFAL-MG), Str. Gabriel Monteiro da Silva, Alfenas, Minas Gerais, Brazil
| | - Sabatino Maione
- Division of Pharmacology, Department of Experimental Medicine, University of Campania "L. Vanvitelli," Naples, Italy.,IRCCS Neuromed, 86077, Pozzilli-Caserta, Italy
| | - Norberto Cysne Coimbra
- Laboratory of Neurosciences of Pain & Emotions and Neuroelectrophysiology Multi-User Centre, Department of Surgery and Anatomy, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Ribeirão Preto, São Paulo, Brazil.,Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Ribeirão Preto, São Paulo, Brazil.,Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Renato Leonardo de Freitas
- Laboratory of Neurosciences of Pain & Emotions and Neuroelectrophysiology Multi-User Centre, Department of Surgery and Anatomy, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Ribeirão Preto, São Paulo, Brazil.,Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Ribeirão Preto, São Paulo, Brazil.,Department of Psychology, Ribeirão Preto School of Philosophy, Sciences and Literature of the University of São Paulo, Ribeirão Preto, São Paulo, Brazil.,Biomedical Sciences Institute, Federal University of Alfenas (UNIFAL-MG), Str. Gabriel Monteiro da Silva, Alfenas, Minas Gerais, Brazil
| |
Collapse
|
20
|
Ramírez-López A, Pastor A, de la Torre R, La Porta C, Ozaita A, Cabañero D, Maldonado R. Role of the endocannabinoid system in a mouse model of Fragile X undergoing neuropathic pain. Eur J Pain 2021; 25:1316-1328. [PMID: 33619843 DOI: 10.1002/ejp.1753] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Neuropathic pain is a complex condition characterized by sensory, cognitive and affective symptoms that magnify the perception of pain. The underlying pathogenic mechanisms are largely unknown and there is an urgent need for the development of novel medications. The endocannabinoid system modulates pain perception and drugs targeting the cannabinoid receptor type 2 (CB2) devoid of psychoactive side effects could emerge as novel analgesics. An interesting model to evaluate the mechanisms underlying resistance to pain is the fragile X mental retardation protein knockout mouse (Fmr1KO), a model of fragile X syndrome that exhibits nociceptive deficits and fails to develop neuropathic pain. METHODS A partial sciatic nerve ligation was performed to wild-type (WT) and Fmr1KO mice having (HzCB2 and Fmr1KO-HzCB2, respectively) or not (WT and Fmr1KO mice) a partial deletion of CB2 to investigate the participation of the endocannabinoid system on the pain-resistant phenotype of Fmr1KO mice. RESULTS Nerve injury induced canonical hypersensitivity in WT and HzCB2 mice, whereas this increased pain sensitivity was absent in Fmr1KO mice. Interestingly, Fmr1KO mice partially lacking CB2 lost this protection against neuropathic pain. Similarly, pain-induced depressive-like behaviour was observed in WT, HzCB2 and Fmr1KO-HzCB2 mice, but not in Fmr1KO littermates. Nerve injury evoked different alterations in WT and Fmr1KO mice at spinal and supra-spinal levels that correlated with these nociceptive and emotional alterations. CONCLUSIONS This work shows that CB2 is necessary for the protection against neuropathic pain observed in Fmr1KO mice, raising the interest in targeting this receptor for the treatment of neuropathic pain. SIGNIFICANCE Neuropathic pain is a complex chronic pain condition and current treatments are limited by the lack of efficacy and the incidence of important side effects. Our findings show that the pain-resistant phenotype of Fmr1KO mice against nociceptive and emotional manifestations triggered by persistent nerve damage requires the participation of the cannabinoid receptor CB2, raising the interest in targeting this receptor for neuropathic pain treatment. Additional multidisciplinary studies more closely related to human pain experience should be conducted to explore the potential use of cannabinoids as adequate analgesic tools.
Collapse
Affiliation(s)
- Angela Ramírez-López
- Barcelona Biomedical Research Park (PRBB), University Pompeu Fabra, Barcelona, Spain
| | - Antoni Pastor
- IMIM-Hospital del Mar Research Institute, Barcelona, Spain
| | | | - Carmen La Porta
- Barcelona Biomedical Research Park (PRBB), University Pompeu Fabra, Barcelona, Spain
| | - Andrés Ozaita
- Barcelona Biomedical Research Park (PRBB), University Pompeu Fabra, Barcelona, Spain
| | - David Cabañero
- Barcelona Biomedical Research Park (PRBB), University Pompeu Fabra, Barcelona, Spain
| | - Rafael Maldonado
- Barcelona Biomedical Research Park (PRBB), University Pompeu Fabra, Barcelona, Spain.,IMIM-Hospital del Mar Research Institute, Barcelona, Spain
| |
Collapse
|
21
|
Cortical Modulation of Nociception. Neuroscience 2021; 458:256-270. [PMID: 33465410 DOI: 10.1016/j.neuroscience.2021.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 11/28/2020] [Accepted: 01/03/2021] [Indexed: 02/06/2023]
Abstract
Nociception is the neuronal process of encoding noxious stimuli and could be modulated at peripheral, spinal, brainstem, and cortical levels. At cortical levels, several areas including the anterior cingulate cortex (ACC), prefrontal cortex (PFC), ventrolateral orbital cortex (VLO), insular cortex (IC), motor cortex (MC), and somatosensory cortices are involved in nociception modulation through two main mechanisms: (i) a descending modulatory effect at spinal level by direct corticospinal projections or mostly by activation of brainstem structures (i.e. periaqueductal grey matter (PAG), locus coeruleus (LC), the nucleus of raphe (RM) and rostroventral medulla (RVM)); and by (ii) cortico-cortical or cortico-subcortical interactions. This review summarizes evidence related to the participation of the aforementioned cortical areas in nociception modulation and different neurotransmitters or neuromodulators that have been studied in each area. Besides, we point out the importance of considering intracortical neuronal populations and receptors expression, as well as, nociception-induced cortical changes, both functional and connectional, to better understand this modulatory effect. Finally, we discuss the possible mechanisms that could potentiate the use of cortical stimulation as a promising procedure in pain alleviation.
Collapse
|
22
|
Li D, Chung G, Kim SK. The Involvement of Central Noradrenergic Pathway in the Analgesic Effect of Bee Venom Acupuncture on Vincristine-Induced Peripheral Neuropathy in Rats. Toxins (Basel) 2020; 12:toxins12120775. [PMID: 33291335 PMCID: PMC7762247 DOI: 10.3390/toxins12120775] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/03/2020] [Accepted: 12/04/2020] [Indexed: 12/15/2022] Open
Abstract
Vincristine is a vinca alkaloid anti-mitotic drug with a broad spectrum of effects on solid and hematologic cancers. The major dose-limiting factor of this anti-cancer regimen is painful peripheral neuropathy. However, no gold-standard analgesic option has been used clinically. In this study, we investigated the effects and mechanism of bee venom acupuncture (BVA) to alleviate peripheral neuropathic pain induced by repeated intraperitoneal infusions of vincristine (1 mg/kg/day, days 1–5 and 8–12) in rats. Subcutaneous injection with bee venom (BV, 1.0 mg/kg) at the ST36 acupoint ameliorated cold and mechanical hypersensitivity (i.e., aberrant withdrawal responses in acetone drop and von Frey hair tests, respectively). In vivo extracellular recording demonstrated that BVA inhibited cutaneous cold (acetone) and mechanical (brush, press, and pinch) stimuli-elicited abnormal hyperexcitation of the spinal wide dynamic range (WDR) neurons in vincristine-treated rats. In addition, the microinjection of lidocaine into the ipsilateral locus coeruleus or the antagonism of the spinal α2-adrenergic receptors clearly reversed the effects of BVA on cold and mechanical hypersensitivity, indicating a vital role of the descending noradrenergic modulation in analgesia. These findings suggest that BVA could be a potential therapeutic option for vincristine-induced peripheral neuropathy.
Collapse
Affiliation(s)
- Daxian Li
- Department of Science in Korean Medicine, Graduate School, Kyung Hee University, Seoul 02447, Korea;
| | - Geehoon Chung
- Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul 02447, Korea;
| | - Sun Kwang Kim
- Department of Science in Korean Medicine, Graduate School, Kyung Hee University, Seoul 02447, Korea;
- Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul 02447, Korea;
- Department of East-West Medicine, Graduate School, Kyung Hee University, Seoul 02447, Korea
- Correspondence:
| |
Collapse
|
23
|
Chronic pain impact on rodents’ behavioral repertoire. Neurosci Biobehav Rev 2020; 119:101-127. [DOI: 10.1016/j.neubiorev.2020.09.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 07/14/2020] [Accepted: 09/21/2020] [Indexed: 12/20/2022]
|
24
|
Persistent Activity of Metabotropic Glutamate Receptor 5 in the Periaqueductal Gray Constrains Emergence of Chronic Neuropathic Pain. Curr Biol 2020; 30:4631-4642.e6. [PMID: 32976802 DOI: 10.1016/j.cub.2020.09.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 07/15/2020] [Accepted: 09/03/2020] [Indexed: 12/13/2022]
Abstract
Pain sensation is powerfully modulated by signal processing in the brain, and pain becomes chronic with the dysfunction of the pain modulatory system; however, the underlying mechanisms are unclear. We found that the metabotropic glutamate receptor 5 (mGluR5) in the periaqueductal gray (PAG), the key area of endogenous pain modulation, is persistently active in normal conditions to maintain an appropriate sensory perception. In the neuropathic pain condition, Homer1a, an activity-dependent immediate early gene product, disrupted the persistent mGluR5 activity resulting in chronic pain. Remarkably a single-time blockage of the mGluR5 resulted in chronic neuropathic pain-like symptoms even in the absence of nerve injury. The decline of mGluR5 activity induced the pain modulatory dysfunction with a profound reduction of excitability of PAG neurons. These findings uncover the role of the persistent mGluR5 activity in vivo and provide new insight into how pain becomes chronic with the maladaptive coping of the PAG to pain sensation.
Collapse
|
25
|
Kummer KK, Mitrić M, Kalpachidou T, Kress M. The Medial Prefrontal Cortex as a Central Hub for Mental Comorbidities Associated with Chronic Pain. Int J Mol Sci 2020; 21:E3440. [PMID: 32414089 PMCID: PMC7279227 DOI: 10.3390/ijms21103440] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/06/2020] [Accepted: 05/07/2020] [Indexed: 12/13/2022] Open
Abstract
Chronic pain patients frequently develop and suffer from mental comorbidities such as depressive mood, impaired cognition, and other significant constraints of daily life, which can only insufficiently be overcome by medication. The emotional and cognitive components of pain are processed by the medial prefrontal cortex, which comprises the anterior cingulate cortex, the prelimbic, and the infralimbic cortex. All three subregions are significantly affected by chronic pain: magnetic resonance imaging has revealed gray matter loss in all these areas in chronic pain conditions. While the anterior cingulate cortex appears hyperactive, prelimbic, and infralimbic regions show reduced activity. The medial prefrontal cortex receives ascending, nociceptive input, but also exerts important top-down control of pain sensation: its projections are the main cortical input of the periaqueductal gray, which is part of the descending inhibitory pain control system at the spinal level. A multitude of neurotransmitter systems contributes to the fine-tuning of the local circuitry, of which cholinergic and GABAergic signaling are particularly emerging as relevant components of affective pain processing within the prefrontal cortex. Accordingly, factors such as distraction, positive mood, and anticipation of pain relief such as placebo can ameliorate pain by affecting mPFC function, making this cortical area a promising target region for medical as well as psychosocial interventions for pain therapy.
Collapse
Affiliation(s)
| | | | | | - Michaela Kress
- Institute of Physiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (K.K.K.); (M.M.); (T.K.)
| |
Collapse
|
26
|
Nag S, Varnäs K, Arakawa R, Jahan M, Schou M, Farde L, Halldin C. Synthesis, Biodistribution, and Radiation Dosimetry of a Novel mGluR5 Radioligand: 18F-AZD9272. ACS Chem Neurosci 2020; 11:1048-1057. [PMID: 32167745 PMCID: PMC7309225 DOI: 10.1021/acschemneuro.9b00680] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
![]()
The metabotropic
glutamate receptor subtype mGluR5 has been proposed
as a potential drug target for CNS disorders such as anxiety, depression,
Parkinson’s disease, and epilepsy. The AstraZeneca compound
AZD9272 has previously been labeled with carbon-11 and used as a PET
radioligand for mGluR5 receptor binding. The molecular structure of
AZD9272 allows one to label the molecule with fluorine-18 without
altering the structure. The aim of this study was to develop a fluorine-18
analogue of AZD9272 and to examine its binding distribution in the
nonhuman primate brain in vivo as well as to obtain
whole body radiation dosimetry. 18F-AZD9272 was successfully
synthesized from a nitro precursor. The radioligand was stable, with
a radiochemical purity of >99% at 2 h after formulation in a sterile
phosphate buffered solution (pH = 7.4). After injection of 18F-AZD9272 in two cynomolgus monkeys, the maximum whole brain radioactivity
concentration was 4.9–6.7% of the injected dose (n = 2) and PET images showed a pattern of regional radioactivity consistent
with that previously obtained for 11C-AZD9272. The percentage
of parent radioligand in plasma was 59 and 64% (n = 2) at 120 min after injection of 18F-AZD9272, consistent
with high metabolic stability. Two whole body PET scans were performed
in nonhuman primates for a total of 231 min after injection of 18F-AZD9272. Highest uptakes were seen in liver and small intestine,
followed by brain and kidney. The estimated effective dose was around
0.017 mSv/MBq. 18F-AZD9272 shows suitable properties as
a PET radioligand for in vivo imaging of binding
in the primate brain. 18F-labeled AZD9272 offers advantages
over 11C-AZD9272 in terms of higher image resolution, combined
with a longer half-life. Moreover, based on the distribution and the
estimated radiation burden, imaging of 18F-AZD9272 could
be used as an improved tool for quantitative assessment and characterization
of AZD9272 binding sites in the human brain by using PET.
Collapse
Affiliation(s)
- Sangram Nag
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm 17176, Sweden
| | - Katarina Varnäs
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm 17176, Sweden
| | - Ryosuke Arakawa
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm 17176, Sweden
| | - Mahabuba Jahan
- Department of Medicinal Chemistry, Uppsala University, Uppsala 751 05, Sweden
| | - Magnus Schou
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm 17176, Sweden
- PET Science Centre, Precision Medicine, Oncology R&D, AstraZeneca, Stockholm 17176, Sweden
| | - Lars Farde
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm 17176, Sweden
| | - Christer Halldin
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm 17176, Sweden
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 639798
| |
Collapse
|
27
|
Kremer M, Becker LJ, Barrot M, Yalcin I. How to study anxiety and depression in rodent models of chronic pain? Eur J Neurosci 2020; 53:236-270. [DOI: 10.1111/ejn.14686] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 01/06/2020] [Accepted: 01/14/2020] [Indexed: 02/06/2023]
Affiliation(s)
- Mélanie Kremer
- Centre National de la Recherche Scientifique Institut des Neurosciences Cellulaires et Intégratives Université de Strasbourg Strasbourg France
| | - Léa J. Becker
- Centre National de la Recherche Scientifique Institut des Neurosciences Cellulaires et Intégratives Université de Strasbourg Strasbourg France
| | - Michel Barrot
- Centre National de la Recherche Scientifique Institut des Neurosciences Cellulaires et Intégratives Université de Strasbourg Strasbourg France
| | - Ipek Yalcin
- Centre National de la Recherche Scientifique Institut des Neurosciences Cellulaires et Intégratives Université de Strasbourg Strasbourg France
| |
Collapse
|
28
|
Suppressive Effects of Bee Venom-Derived Phospholipase A2 on Mechanical Allodynia in a Rat Model of Neuropathic Pain. Toxins (Basel) 2019; 11:toxins11080477. [PMID: 31430923 PMCID: PMC6723753 DOI: 10.3390/toxins11080477] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 08/14/2019] [Accepted: 08/15/2019] [Indexed: 11/30/2022] Open
Abstract
Bee venom (BV) has a long history of being used in traditional Korean medicine to relieve pain. Here, we investigated the effect of BV-derived phospholipase A2 (bvPLA2), a major component of BV, on peripheral nerve injury-induced neuropathic pain in rats. Spinal nerve ligation (SNL) was performed in Sprague Dawley rats to induce neuropathic pain, and paw withdrawal thresholds were measured using von Frey test. Mechanical allodynia, the representative symptom of neuropathic pain, was manifested following SNL and persisted for several weeks. The repetitive bvPLA2 treatment (0.2 mg/kg/day, i.p.) for two days significantly relieved the SNL-induced mechanical allodynia. The antiallodynic effect of bvPLA2 was blocked by spinal pretreatment with α1-adrenergic antagonist prazosin (30 μg, i.t.) but not with α2-adrenergic antagonist idazoxan (50 μg, i.t.). Also, the spinal application of α1-adrenergic agonist phenylephrine (50 μg, i.t.) reduced mechanical allodynia. These results indicate that bvPLA2 could relieve nerve injury-induced neuropathic mechanical allodynia through the activation of spinal α1-adrenergic receptors.
Collapse
|
29
|
Medeiros P, de Freitas RL, Boccella S, Iannotta M, Belardo C, Mazzitelli M, Romano R, De Gregorio D, Coimbra NC, Palazzo E, Maione S. Characterization of the sensory, affective, cognitive, biochemical, and neuronal alterations in a modified chronic constriction injury model of neuropathic pain in mice. J Neurosci Res 2019; 98:338-352. [PMID: 31396990 DOI: 10.1002/jnr.24501] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 06/24/2019] [Accepted: 07/08/2019] [Indexed: 12/12/2022]
Abstract
The chronic constriction injury (CCI) of the sciatic nerve is a nerve injury-based model of neuropathic pain (NP). Comorbidities of NP such as depression, anxiety, and cognitive deficits are associated with a functional reorganization of the medial prefrontal cortex (mPFC). Here, we have employed an adapted model of CCI by placing one single loose ligature around the sciatic nerve in mice for investigating the alterations in sensory, motor, affective, and cognitive behavior and in electrophysiological and biochemical properties in the prelimbic division (PrL) of the mPFC. Our adapted model of CCI induced mechanical allodynia, motor, and cognitive impairments and anxiety- and depression-like behavior. In the PrL division of mPFC was observed an increase in GABA and a decrease in d-aspartate levels. Moreover an increase in the activity of neurons responding to mechanical stimulation with an excitation, mPFC (+), and a decrease in those responding with an inhibition, mPFC (-), was found. Altogether these findings demonstrate that a single ligature around the sciatic nerve was able to induce sensory, affective, cognitive, biochemical, and functional alterations already observed in other neuropathic pain models and it may be an appropriate and easily reproducible model for studying neuropathic pain mechanisms and treatments.
Collapse
Affiliation(s)
- Priscila Medeiros
- Division of Pharmacology, Department of Experimental Medicine, Università degli Studi della Campania Luigi Vanvitelli, Naples, Italy.,Laboratory of Neurosciences of Pain & Emotions and Multi-User Centre of Neuroelectrophysiology, Department of Surgery and Anatomy, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Ribeirão Preto (SP), Brazil.,Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, FMRP-USP, Ribeirão Preto, Brazil.,Behavioural Neurosciences Institute (INeC), Ribeirão Preto, Brazil
| | - Renato Leonardo de Freitas
- Division of Pharmacology, Department of Experimental Medicine, Università degli Studi della Campania Luigi Vanvitelli, Naples, Italy.,Laboratory of Neurosciences of Pain & Emotions and Multi-User Centre of Neuroelectrophysiology, Department of Surgery and Anatomy, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Ribeirão Preto (SP), Brazil.,Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, FMRP-USP, Ribeirão Preto, Brazil.,Behavioural Neurosciences Institute (INeC), Ribeirão Preto, Brazil.,Biomedical Sciences Institute, Federal University of Alfenas (UNIFAL), Alfenas (MG), Brazil
| | - Serena Boccella
- Division of Pharmacology, Department of Experimental Medicine, Università degli Studi della Campania Luigi Vanvitelli, Naples, Italy
| | - Monica Iannotta
- Division of Pharmacology, Department of Experimental Medicine, Università degli Studi della Campania Luigi Vanvitelli, Naples, Italy
| | - Carmela Belardo
- Division of Pharmacology, Department of Experimental Medicine, Università degli Studi della Campania Luigi Vanvitelli, Naples, Italy
| | - Mariacristina Mazzitelli
- Division of Pharmacology, Department of Experimental Medicine, Università degli Studi della Campania Luigi Vanvitelli, Naples, Italy
| | - Rosaria Romano
- Division of Pharmacology, Department of Experimental Medicine, Università degli Studi della Campania Luigi Vanvitelli, Naples, Italy
| | - Danilo De Gregorio
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Norberto Cysne Coimbra
- Laboratory of Neurosciences of Pain & Emotions and Multi-User Centre of Neuroelectrophysiology, Department of Surgery and Anatomy, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Ribeirão Preto (SP), Brazil.,Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, FMRP-USP, Ribeirão Preto, Brazil.,Behavioural Neurosciences Institute (INeC), Ribeirão Preto, Brazil
| | - Enza Palazzo
- Division of Pharmacology, Department of Experimental Medicine, Università degli Studi della Campania Luigi Vanvitelli, Naples, Italy
| | - Sabatino Maione
- Division of Pharmacology, Department of Experimental Medicine, Università degli Studi della Campania Luigi Vanvitelli, Naples, Italy
| |
Collapse
|
30
|
Neuroimaging of pain in animal models: a review of recent literature. Pain Rep 2019; 4:e732. [PMID: 31579844 PMCID: PMC6728006 DOI: 10.1097/pr9.0000000000000732] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 02/06/2019] [Accepted: 02/12/2019] [Indexed: 01/19/2023] Open
Abstract
Neuroimaging of pain in animals allows us to better understand mechanisms of pain processing and modulation. In this review, we discuss recently published brain imaging studies in rats, mice, and monkeys, including functional magnetic resonance imaging (MRI), manganese-enhanced MRI, positron emission tomography, and electroencephalography. We provide an overview of innovations and limitations in neuroimaging techniques, as well as results of functional brain imaging studies of pain from January 1, 2016, to October 10, 2018. We then discuss how future investigations can address some bias and gaps in the field. Despite the limitations of neuroimaging techniques, the 28 studies reinforced that transition from acute to chronic pain entails considerable changes in brain function. Brain activations in acute pain were in areas more related to the sensory aspect of noxious stimulation, including primary somatosensory cortex, insula, cingulate cortex, thalamus, retrosplenial cortex, and periaqueductal gray. Pharmacological and nonpharmacological treatments modulated these brain regions in several pain models. On the other hand, in chronic pain models, brain activity was observed in regions commonly associated with emotion and motivation, including prefrontal cortex, anterior cingulate cortex, hippocampus, amygdala, basal ganglia, and nucleus accumbens. Neuroimaging of pain in animals holds great promise for advancing our knowledge of brain function and allowing us to expand human subject research. Additional research is needed to address effects of anesthesia, analysis approaches, sex bias and omission, and potential effects of development and aging.
Collapse
|
31
|
Becker S, Bräscher AK, Bannister S, Bensafi M, Calma-Birling D, Chan RCK, Eerola T, Ellingsen DM, Ferdenzi C, Hanson JL, Joffily M, Lidhar NK, Lowe LJ, Martin LJ, Musser ED, Noll-Hussong M, Olino TM, Pintos Lobo R, Wang Y. The role of hedonics in the Human Affectome. Neurosci Biobehav Rev 2019; 102:221-241. [PMID: 31071361 PMCID: PMC6931259 DOI: 10.1016/j.neubiorev.2019.05.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 03/25/2019] [Accepted: 05/03/2019] [Indexed: 01/06/2023]
Abstract
Experiencing pleasure and displeasure is a fundamental part of life. Hedonics guide behavior, affect decision-making, induce learning, and much more. As the positive and negative valence of feelings, hedonics are core processes that accompany emotion, motivation, and bodily states. Here, the affective neuroscience of pleasure and displeasure that has largely focused on the investigation of reward and pain processing, is reviewed. We describe the neurobiological systems of hedonics and factors that modulate hedonic experiences (e.g., cognition, learning, sensory input). Further, we review maladaptive and adaptive pleasure and displeasure functions in mental disorders and well-being, as well as the experience of aesthetics. As a centerpiece of the Human Affectome Project, language used to express pleasure and displeasure was also analyzed, and showed that most of these analyzed words overlap with expressions of emotions, actions, and bodily states. Our review shows that hedonics are typically investigated as processes that accompany other functions, but the mechanisms of hedonics (as core processes) have not been fully elucidated.
Collapse
Affiliation(s)
- Susanne Becker
- Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, J5, 68159 Mannheim, Germany.
| | - Anne-Kathrin Bräscher
- Department of Clinical Psychology, Psychotherapy and Experimental Psychopathology, University of Mainz, Wallstr. 3, 55122 Mainz, Germany.
| | | | - Moustafa Bensafi
- Research Center in Neurosciences of Lyon, CNRS UMR5292, INSERM U1028, Claude Bernard University Lyon 1, Lyon, Centre Hospitalier Le Vinatier, 95 bd Pinel, 69675 Bron Cedex, France.
| | - Destany Calma-Birling
- Department of Psychology, University of Wisconsin-Oshkosh, 800 Algoma, Blvd., Clow F011, Oshkosh, WI 54901, USA.
| | - Raymond C K Chan
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China.
| | - Tuomas Eerola
- Durham University, Palace Green, DH1 RL3, Durham, UK.
| | - Dan-Mikael Ellingsen
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, CNY149-2301, 13th St, Charlestown, MA 02129, USA.
| | - Camille Ferdenzi
- Research Center in Neurosciences of Lyon, CNRS UMR5292, INSERM U1028, Claude Bernard University Lyon 1, Lyon, Centre Hospitalier Le Vinatier, 95 bd Pinel, 69675 Bron Cedex, France.
| | - Jamie L Hanson
- University of Pittsburgh, Department of Psychology, 3939 O'Hara Street, Rm. 715, Pittsburgh, PA 15206, USA.
| | - Mateus Joffily
- Groupe d'Analyse et de Théorie Economique (GATE), 93 Chemin des Mouilles, 69130, Écully, France.
| | - Navdeep K Lidhar
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada.
| | - Leroy J Lowe
- Neuroqualia (NGO), 36 Arthur Street, Truro, NS, B2N 1X5, Canada.
| | - Loren J Martin
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada.
| | - Erica D Musser
- Department of Psychology, Center for Childen and Families, Florida International University, 11200 SW 8th St., Miami, FL 33199, USA.
| | - Michael Noll-Hussong
- Clinic for Psychiatry and Psychotherapy, Division of Psychosomatic Medicine and Psychotherapy, Saarland University Medical Centre, Kirrberger Strasse 100, D-66421 Homburg, Germany.
| | - Thomas M Olino
- Temple University, Department of Psychology, 1701N. 13th St, Philadelphia, PA 19010, USA.
| | - Rosario Pintos Lobo
- Department of Psychology, Center for Childen and Families, Florida International University, 11200 SW 8th St., Miami, FL 33199, USA.
| | - Yi Wang
- Neuropsychology and Applied Cognitive Neuroscience Laboratory, CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China.
| |
Collapse
|
32
|
Decoding neuropathic pain severity using distinct patterns of corticolimbic metabotropic glutamate receptor 5. Neuroimage 2019; 190:303-312. [DOI: 10.1016/j.neuroimage.2018.07.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 06/08/2018] [Accepted: 07/06/2018] [Indexed: 12/27/2022] Open
|
33
|
Humo M, Lu H, Yalcin I. The molecular neurobiology of chronic pain-induced depression. Cell Tissue Res 2019; 377:21-43. [PMID: 30778732 DOI: 10.1007/s00441-019-03003-z] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 02/01/2019] [Indexed: 12/18/2022]
Abstract
The increasing number of individuals with comorbidities poses an urgent need to improve the management of patients with multiple co-existing diseases. Among these comorbidities, chronic pain and mood disorders, two long-lasting disabling conditions that significantly reduce the quality of life, could be cited first. The recent development of animal models accelerated the studies focusing on the underlying mechanisms of the chronic pain and depression/anxiety comorbidity. This review provides an overview of clinical and pre-clinical studies performed over the past two decades addressing the molecular aspects of the comorbid relationship of chronic pain and depression. We thus focused on the studies that investigated the molecular characteristics of the comorbid relationship between chronic pain and mood disorders, especially major depressive disorders, from the genetic and epigenetic point of view to key neuromodulators which have been shown to play an important role in this comorbidity.
Collapse
Affiliation(s)
- Muris Humo
- Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique et Université de Strasbourg, 67000, Strasbourg, France
| | - Han Lu
- Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique et Université de Strasbourg, 67000, Strasbourg, France.,Faculty of Biology and Bernstein Center Freiburg, University of Freiburg, D-79104, Freiburg, Germany
| | - Ipek Yalcin
- Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique et Université de Strasbourg, 67000, Strasbourg, France.
| |
Collapse
|
34
|
Pereira V, Goudet C. Emerging Trends in Pain Modulation by Metabotropic Glutamate Receptors. Front Mol Neurosci 2019; 11:464. [PMID: 30662395 PMCID: PMC6328474 DOI: 10.3389/fnmol.2018.00464] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 11/30/2018] [Indexed: 12/20/2022] Open
Abstract
Pain is an essential protective mechanism meant to prevent tissue damages in organisms. On the other hand, chronic or persistent pain caused, for example, by inflammation or nerve injury is long lasting and responsible for long-term disability in patients. Therefore, chronic pain and its management represents a major public health problem. Hence, it is critical to better understand chronic pain molecular mechanisms to develop innovative and efficient drugs. Over the past decades, accumulating evidence has demonstrated a pivotal role of glutamate in pain sensation and transmission, supporting glutamate receptors as promising potential targets for pain relieving drug development. Glutamate is the most abundant excitatory neurotransmitter in the brain. Once released into the synapse, glutamate acts through ionotropic glutamate receptors (iGluRs), which are ligand-gated ion channels triggering fast excitatory neurotransmission, and metabotropic glutamate receptors (mGluRs), which are G protein-coupled receptors modulating synaptic transmission. Eight mGluRs subtypes have been identified and are divided into three classes based on their sequence similarities and their pharmacological and biochemical properties. Of note, all mGluR subtypes (except mGlu6 receptor) are expressed within the nociceptive pathways where they modulate pain transmission. This review will address the role of mGluRs in acute and persistent pain processing and emerging pharmacotherapies for pain management.
Collapse
Affiliation(s)
- Vanessa Pereira
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, France
| | - Cyril Goudet
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, France
| |
Collapse
|
35
|
Abstract
Pain has a strong emotional component and is defined by its unpleasantness. Chronic pain represents a complex disorder with anxio-depressive symptoms and cognitive deficits. Underlying mechanisms are still not well understood but an important role for interactions between prefrontal cortical areas and subcortical limbic structures has emerged. Evidence from preclinical studies in the rodent brain suggests that neuroplastic changes in prefrontal (anterior cingulate, prelimbic and infralimbic) cortical and subcortical (amygdala and nucleus accumbens) brain areas and their interactions (corticolimbic circuitry) contribute to the complexity and persistence of pain and may be predetermining factors as has been proposed in recent human neuroimaging studies.
Collapse
Affiliation(s)
- Jeremy M Thompson
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, School of Medicine, Lubbock, TX, United States
| | - Volker Neugebauer
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, School of Medicine, Lubbock, TX, United States; Center of Excellence for Translational Neuroscience and Therapeutics, Texas Tech University Health Sciences Center, Lubbock, TX, United States.
| |
Collapse
|
36
|
Chung G, Kim SJ, Kim SK. Metabotropic Glutamate Receptor 5 in the Medial Prefrontal Cortex as a Molecular Determinant of Pain and Ensuing Depression. Front Mol Neurosci 2018; 11:376. [PMID: 30349459 PMCID: PMC6186831 DOI: 10.3389/fnmol.2018.00376] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Accepted: 09/21/2018] [Indexed: 12/27/2022] Open
Abstract
Pain and depression affect one another, and this bidirectional interaction implies the existence of common or interacting neural pathways. Among the neural circuits relevant to negative affection, the medial prefrontal cortex (mPFC) is known to be involved in both pain and depression. Persistent stress from physical pain and mental distress can evoke maladaptive changes in mPFC circuits to induce depression. Conversely, the unpleasant mood condition alters mPFC circuits to distort the appraisal of aversion and make individuals vulnerable to pain. In this article, recent findings regarding mPFC in chronic pain and/or depression are reviewed, with particular focus on the metabotropic glutamate receptor 5 (mGluR5). Although the involvement of mGluR5 within the mPFC in both pain and depressive disorders has been extensively studied, there are controversies regarding changes in the activity of the mPFC during chronic pain and depression, and the functional roles of mGluR5 on altered mPFC activity. We discuss alterations in the availability of mGluR5 in the mPFC in these disorders, its role in behavioral manifestations, and its possible influence on cellular subpopulations that mediate dysfunction in the mPFC. We also propose molecular mechanisms that may cause expressional changes in mGluR5 within the mPFC circuitry.
Collapse
Affiliation(s)
- Geehoon Chung
- Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul, South Korea.,Department of Physiology, College of Medicine, Seoul National University, Seoul, South Korea
| | - Sang Jeong Kim
- Department of Physiology, College of Medicine, Seoul National University, Seoul, South Korea
| | - Sun Kwang Kim
- Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul, South Korea
| |
Collapse
|
37
|
Boccella S, Cristiano C, Romano R, Iannotta M, Belardo C, Farina A, Guida F, Piscitelli F, Palazzo E, Mazzitelli M, Imperatore R, Tunisi L, de Novellis V, Cristino L, Di Marzo V, Calignano A, Maione S, Luongo L. Ultra-micronized palmitoylethanolamide rescues the cognitive decline-associated loss of neural plasticity in the neuropathic mouse entorhinal cortex-dentate gyrus pathway. Neurobiol Dis 2018; 121:106-119. [PMID: 30266286 DOI: 10.1016/j.nbd.2018.09.023] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 09/10/2018] [Accepted: 09/24/2018] [Indexed: 02/08/2023] Open
Abstract
Chronic pain is associated with cognitive deficits. Palmitoylethanolamide (PEA) has been shown to ameliorate pain and pain-related cognitive impairments by restoring glutamatergic synapses functioning in the spared nerve injury (SNI) of the sciatic nerve in mice. SNI reduced mechanical and thermal threshold, spatial memory and LTP at the lateral entorhinal cortex (LEC)-dentate gyrus (DG) pathway. It decreased also postsynaptic density, volume and dendrite arborization of DG and increased the expression of metabotropic glutamate receptor 1 and 7 (mGluR1 and mGluR7), of the GluR1, GluR1s845 and GluR1s831 subunits of AMPA receptor and the levels of glutamate in the DG. The level of the endocannabinoid 2-arachidonoylglycerol (2-AG) was instead increased in the LEC. Chronic treatment with PEA, starting from when neuropathic pain was fully developed, was able to reverse mechanical allodynia and thermal hyperalgesia, memory deficit and LTP in SNI wild type, but not in PPARα null, mice. PEA also restored the level of glutamate and the expression of phosphorylated GluR1 subunits, postsynaptic density and neurogenesis. Altogether, these results suggest that neuropathic pain negatively affects cognitive behavior and related LTP, glutamatergic synapse and synaptogenesis in the DG. In these conditions PEA treatment alleviates pain and cognitive impairment by restoring LTP and synaptic maladaptative changes in the LEC-DG pathway. These outcomes open new perspectives for the use of the N-acylethanolamines, such as PEA, for the treatment of neuropathic pain and its central behavioural sequelae.
Collapse
Affiliation(s)
- Serena Boccella
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", 80138 Naples, Italy
| | - Claudia Cristiano
- Department of Pharmacy, School of Medicine, University of Naples Federico II, Naples, Italy
| | - Rosaria Romano
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", 80138 Naples, Italy
| | - Monica Iannotta
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", 80138 Naples, Italy
| | - Carmela Belardo
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", 80138 Naples, Italy
| | - Antonio Farina
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", 80138 Naples, Italy
| | - Francesca Guida
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", 80138 Naples, Italy
| | - Fabiana Piscitelli
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, CNR, Pozzuoli, Italy
| | - Enza Palazzo
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", 80138 Naples, Italy
| | - Mariacristina Mazzitelli
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX
| | - Roberta Imperatore
- Department of Science and Technology, University of Sannio, Benevento, Italy
| | - Lea Tunisi
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, CNR, Pozzuoli, Italy
| | - Vito de Novellis
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", 80138 Naples, Italy
| | - Luigia Cristino
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, CNR, Pozzuoli, Italy
| | - Vincenzo Di Marzo
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, CNR, Pozzuoli, Italy
| | - Antonio Calignano
- Department of Pharmacy, School of Medicine, University of Naples Federico II, Naples, Italy
| | - Sabatino Maione
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", 80138 Naples, Italy
| | - Livio Luongo
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", 80138 Naples, Italy.
| |
Collapse
|
38
|
Seno MDJ, Assis DV, Gouveia F, Antunes GF, Kuroki M, Oliveira CC, Santos LCT, Pagano RL, Martinez RCR. The critical role of amygdala subnuclei in nociceptive and depressive-like behaviors in peripheral neuropathy. Sci Rep 2018; 8:13608. [PMID: 30206257 PMCID: PMC6134132 DOI: 10.1038/s41598-018-31962-w] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 08/30/2018] [Indexed: 01/05/2023] Open
Abstract
The amygdala is an important component of the limbic system that participates in the control of the pain response and modulates the affective-motivational aspect of pain. Neuropathic pain is a serious public health problem and has a strong affective-motivational component that makes it difficult to treat. The central (CeA), basolateral (BLA) and lateral (LA) nuclei of the amygdala are involved in the processing and regulation of chronic pain. However, the roles of these nuclei in the maintenance of neuropathic pain, anxiety and depression remain unclear. Thus, the main objective of this study was to investigate the role of amygdala subnuclei in the modulation of neuropathic pain, including the affective-motivational axis, in an experimental model of peripheral neuropathy. The specific goals were as follows: (1) To evaluate the nociceptive responses and the patterns of activation of the CeA, BLA and LA in neuropathic rats; and (2) To evaluate the effect of inactivating the amygdala nuclei on the nociceptive response, anxiety and depressive behaviors, motor activity, and plasma stress hormones in animals with neuropathic pain. Thus, mechanical hyperalgesia and allodynia, and the pattern of c-Fos staining in the amygdala subnuclei were evaluated in rats with chronic constriction of the sciatic nerve, as well as sham-operated and naïve rats. Once the amygdala subnuclei involved in neuropathic pain response were defined, those subnuclei were pharmacological inactivated. The effect of muscimol inactivation on the nociceptive response (hyperalgesia and allodynia), anxiety (elevated plus-maze), depressive-like behavior (forced swim test), motor activity (open field), and plasma stress hormone levels (corticosterone and adrenocorticotropic hormone) were evaluated in sham-operated and neuropathic animals. The results showed that the anterior and posterior portions of the BLA and the central portion of the CeA are involved in controlling neuropathic pain. The inactivation of these nuclei reversed hyperalgesia, allodynia and depressive-like behavior in animals with peripheral neuropathy. Taken together, our findings improve our understanding of the neurocircuitry involved in persistent pain and the roles of specific amygdala subnuclei in the modulation of neuropathic pain, including the neurocircuitry that processes the affective-motivational component of pain.
Collapse
Affiliation(s)
- Midiã D J Seno
- Laboratory of Neuroscience, Hospital Sirio-Libanes, Sao Paulo, SP, Brazil
| | - Danielle V Assis
- Laboratory of Neuroscience, Hospital Sirio-Libanes, Sao Paulo, SP, Brazil
| | - Flávia Gouveia
- Laboratory of Neuroscience, Hospital Sirio-Libanes, Sao Paulo, SP, Brazil
| | - Geiza F Antunes
- Laboratory of Neuroscience, Hospital Sirio-Libanes, Sao Paulo, SP, Brazil
| | - Mayra Kuroki
- Laboratory of Neuroscience, Hospital Sirio-Libanes, Sao Paulo, SP, Brazil
| | | | - Lennon C T Santos
- Laboratory of Neuroscience, Hospital Sirio-Libanes, Sao Paulo, SP, Brazil
| | - Rosana L Pagano
- Laboratory of Neuroscience, Hospital Sirio-Libanes, Sao Paulo, SP, Brazil
| | | |
Collapse
|
39
|
Forebrain medial septum sustains experimental neuropathic pain. Sci Rep 2018; 8:11892. [PMID: 30089875 PMCID: PMC6082830 DOI: 10.1038/s41598-018-30177-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 07/25/2018] [Indexed: 12/14/2022] Open
Abstract
The present study explored the role of the medial septal region (MS) in experimental neuropathic pain. For the first time, we found that the MS sustains nociceptive behaviors in rodent models of neuropathic pain, especially in the chronic constriction injury (CCI) model and the paclitaxel model of chemotherapy-induced neuropathic pain. For example, inactivation of the MS with intraseptal muscimol (2 μg/μl, 0.5 μl), a GABA mimetic, reversed peripheral hypersensitivity (PH) in the CCI model and induced place preference in a conditioned place preference task, a surrogate measure of spontaneous nociception. The effect of intraseptal muscimol on PH was comparable to that seen with microinjection of the local anesthetic, lidocaine, into rostral ventromedial medulla which is implicated in facilitating experimental chronic nociception. Cellular analysis in the CCI model showed that the MS region sustains nociceptive gain with CCI by facilitating basal nociceptive processing and the amplification of stimulus-evoked neural processing. Indeed, consistent with the idea that excitatory transmission through MS facilitates chronic experimental pain, intraseptal microinjection of antagonists acting at AMPA and NMDA glutamate receptors attenuated CCI-induced PH. We propose that the MS is a central monitor of bodily nociception which sustains molecular plasticity triggered by persistent noxious insult.
Collapse
|
40
|
Lum JS, Millard SJ, Frank E, Matosin N, Huang XF, Ooi L, Newell KA. Chronic Adolescent CDPPB Treatment Alters Short-Term, but not Long-Term, Glutamatergic Receptor Expression. Neurochem Res 2018; 43:1683-1691. [PMID: 29936568 DOI: 10.1007/s11064-018-2584-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 05/30/2018] [Accepted: 06/20/2018] [Indexed: 12/21/2022]
Abstract
Dysfunction of the glutamatergic system is believed to underlie many neurodevelopmental disorders including autism, Rett syndrome and schizophrenia. Metabotropic glutamate receptor (mGluR5) positive allosteric modulators (PAM) potentiate glutamatergic signaling, particularly indirectly via the NMDA receptor. Preclinical studies report mGluR5 PAMs can improve schizophrenia-relevant behaviours. Furthermore, adolescent administration has shown to prevent cognitive induced deficits in adult rodents. However, there is limited understanding of the short- and long-term neurochemical effects of mGluR5 PAMs, which may underlie their therapeutic effects. We examined the effect of 7-day adolescent (PN28-34) treatment with the mGluR5 PAM, CDDPB (30 mg/kg), on glutamatergic receptor expression at adolescence (PN35) and adulthood (PN96). Immunoblot analysis revealed that 7-day adolescent CDPPB treatment increased protein expression of glutamatergic receptors including the NMDA receptor subunits, NR1 and NR2A and the AMPA subunits (GluA1 and GluA2) in the adolescent hippocampus, changes that did not extend to adulthood. In contrast, there were no changes in the adolescent frontal cortex, however elevated mGluR5 protein expression was observed at adulthood following adolescent CDPPB treatment. The present study indicates adolescent CDPPB treatment may cause brain region dependent effects on the glutamatergic system, which do not persist into adulthood. These findings may have implications for the preclinical development of mGluR5 PAMs for the treatment of neurodevelopmental disorders.
Collapse
Affiliation(s)
- Jeremy S Lum
- School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, 2522, Australia.
- Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia.
- Schizophrenia Research Institute, 405 Liverpool Street, Darlinghurst, NSW, 2010, Australia.
| | - Samuel J Millard
- School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia
| | - Elisabeth Frank
- Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia
- Schizophrenia Research Institute, 405 Liverpool Street, Darlinghurst, NSW, 2010, Australia
| | - Natalie Matosin
- School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia
- Schizophrenia Research Institute, 405 Liverpool Street, Darlinghurst, NSW, 2010, Australia
| | - Xu-Feng Huang
- School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia
| | - Lezanne Ooi
- Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia
- School of Biological Sciences, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Kelly A Newell
- School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia
| |
Collapse
|
41
|
Ong WY, Stohler CS, Herr DR. Role of the Prefrontal Cortex in Pain Processing. Mol Neurobiol 2018; 56:1137-1166. [PMID: 29876878 PMCID: PMC6400876 DOI: 10.1007/s12035-018-1130-9] [Citation(s) in RCA: 347] [Impact Index Per Article: 57.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 05/14/2018] [Indexed: 12/16/2022]
Abstract
The prefrontal cortex (PFC) is not only important in executive functions, but also pain processing. The latter is dependent on its connections to other areas of the cerebral neocortex, hippocampus, periaqueductal gray (PAG), thalamus, amygdala, and basal nuclei. Changes in neurotransmitters, gene expression, glial cells, and neuroinflammation occur in the PFC during acute and chronic pain, that result in alterations to its structure, activity, and connectivity. The medial PFC (mPFC) could serve dual, opposing roles in pain: (1) it mediates antinociceptive effects, due to its connections with other cortical areas, and as the main source of cortical afferents to the PAG for modulation of pain. This is a ‘loop’ where, on one side, a sensory stimulus is transformed into a perceptual signal through high brain processing activity, and perceptual activity is then utilized to control the flow of afferent sensory stimuli at their entrance (dorsal horn) to the CNS. (2) It could induce pain chronification via its corticostriatal projection, possibly depending on the level of dopamine receptor activation (or lack of) in the ventral tegmental area-nucleus accumbens reward pathway. The PFC is involved in biopsychosocial pain management. This includes repetitive transcranial magnetic stimulation, transcranial direct current stimulation, antidepressants, acupuncture, cognitive behavioral therapy, mindfulness, music, exercise, partner support, empathy, meditation, and prayer. Studies demonstrate the role of the PFC during placebo analgesia, and in establishing links between pain and depression, anxiety, and loss of cognition. In particular, losses in PFC grey matter are often reversible after successful treatment of chronic pain.
Collapse
Affiliation(s)
- Wei-Yi Ong
- Department of Anatomy, National University of Singapore, Singapore, 119260, Singapore.
- Neurobiology and Ageing Research Programme, National University of Singapore, Singapore, 119260, Singapore.
| | | | - Deron R Herr
- Department of Pharmacology, National University of Singapore, Singapore, 119260, Singapore.
| |
Collapse
|