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Meijs S, Andreis FR, Janjua TAM, Graven-Nielsen T, Jensen W. High-frequency electrical stimulation increases cortical excitability and mechanical sensitivity in a chronic large animal model. Pain 2024:00006396-990000000-00682. [PMID: 39133034 DOI: 10.1097/j.pain.0000000000003354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 06/12/2024] [Indexed: 08/13/2024]
Abstract
ABSTRACT Translational models of the sensitized pain system are needed to progress the understanding of involved mechanisms. In this study, long-term potentiation was used to develop a mechanism-based large-animal pain model. Event-related potentials to electrical stimulation of the ulnar nerve were recorded by intracranial recordings in pigs, 3 weeks before, immediately before and after, and 3 weeks after peripheral high-frequency stimulation (HFS) applied to the ulnar nerve in the right forelimb (7 pigs) or in control animals (5 pigs). Event-related potential recordings and peripheral HFS were done during anesthesia. Two weeks before and after the HFS, behavioral responses reflecting mechanical and thermal sensitivity were collected using brush, noxious limb-mounted pressure algometer, and noxious laser stimuli. The HFS intervention limb was progressively sensitized to noxious mechanical stimulation in week 1 and 2 compared with baseline (P = 0.045) and the control group (P < 0.034) but not significantly to laser or brush stimulation. The first negative (N1) peak of the event-related potential was increased 30 minutes after HFS compared with before (P < 0.05). The N1 peak was also larger compared with control pigs 20 to 40 minutes after HFS (P < 0.031) but not significantly increased 3 weeks after. The relative increase in N1 30 minutes after HFS and the degree of mechanical hyperalgesia 2 weeks post-HFS was correlated (P < 0.033). These results show for the first time that the pig HFS model resembles the human HFS model closely where the profile of sensitization is comparable. Interestingly, the degree of sensitization was associated with the cortical signs of hyperexcitability at HFS induction.
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Affiliation(s)
- Suzan Meijs
- Department of Health Science and Technology, Center for Neuroplasticity and Pain (CNAP), Aalborg University, Aalborg, Denmark
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Lykholt LED, Mørch CD, Jensen W. Differences in intracortical responses following non-noxious and noxious stimulation in anaesthetized rats. Brain Res 2023; 1821:148564. [PMID: 37678503 DOI: 10.1016/j.brainres.2023.148564] [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: 05/11/2023] [Revised: 08/18/2023] [Accepted: 09/05/2023] [Indexed: 09/09/2023]
Abstract
Cortical responses have been proposed as a source for the extraction of unique and non-subjective sensory information. The present study aimed to investigate if it is possible to distinguish between non-noxious and noxious cortical responses with two different types of anesthesia. Sixteen rats were randomly allocated to receive either Hypnorm/Dormicum (HD) or isoflurane (ISO) anesthesia. Each animal had a custom-made microelectrode array implanted in the primary somatosensory cortex to record the local field potentials and a cuff electrode implanted around the sciatic nerve to deliver electrical stimulations. Three stimulation intensities were applied: 1x movement threshold (MT) (i.e., non-noxious activation), 5x MT (low intensity noxious activation), and 10x MT (high intensity noxious activation). The evoked potentials were assessed by extracting three features: 1) the negative peak (NP), 2) the positive peak (PP), and 3) the peak-to-peak (PtP) amplitudes. Our results showed that it was possible to distinguish between three levels of stimulation intensities based on the NP, PP, and PtP features for the HD group, whereas it was only possible to make the same differentiation with the use of PP and PtP when applying ISO. This work is believed to contribute to a basic understanding of how the cortical responses change in the hyperacute phase of pain and which cortical features may be suitable as objective measures of nociception.
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Affiliation(s)
- L E D Lykholt
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg University, 9220 Aalborg, Denmark.
| | - C D Mørch
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg University, 9220 Aalborg, Denmark
| | - W Jensen
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg University, 9220 Aalborg, Denmark
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Yang CT, Guan Y, Chen CC, Lin WT, Lu KH, Lin CR, Shyu BC, Wen YR. Novel Pulsed Ultrahigh-frequency Spinal Cord Stimulation Inhibits Mechanical Hypersensitivity and Brain Neuronal Activity in Rats after Nerve Injury. Anesthesiology 2023; 139:646-663. [PMID: 37428715 DOI: 10.1097/aln.0000000000004680] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/12/2023]
Abstract
BACKGROUND Spinal cord stimulation (SCS) is an important pain treatment modality. This study hypothesized that a novel pulsed ultrahigh-frequency spinal cord stimulation (pUHF-SCS) could safely and effectively inhibit spared nerve injury-induced neuropathic pain in rats. METHODS Epidural pUHF-SCS (± 3V, 2-Hz pulses comprising 500-kHz biphasic sinewaves) was implanted at the thoracic vertebrae (T9 to T11). Local field brain potentials after hind paw stimulation were recorded. Analgesia was evaluated by von Frey-evoked allodynia and acetone-induced cold allodynia. RESULTS The mechanical withdrawal threshold of the injured paw was 0.91 ± 0.28 g lower than that of the sham surgery (24.9 ± 1.2 g). Applying 5-, 10-, or 20-min pUHF-SCS five times every 2 days significantly increased the paw withdrawal threshold to 13.3 ± 6.5, 18.5 ± 3.6, and 21.0 ± 2.8 g at 5 h post-SCS, respectively (P = 0.0002, < 0.0001, and < 0.0001; n = 6 per group) and to 6.1 ± 2.5, 8.2 ± 2.7, and 14.3 ± 5.9 g on the second day, respectively (P = 0.123, 0.013, and < 0.0001). Acetone-induced paw response numbers decreased from pre-SCS (41 ± 12) to 24 ± 12 and 28 ± 10 (P = 0.006 and 0.027; n = 9) at 1 and 5 h after three rounds of 20-min pUHF-SCS, respectively. The areas under the curve from the C component of the evoked potentials at the left primary somatosensory and anterior cingulate cortices were significantly decreased from pre-SCS (101.3 ± 58.3 and 86.9 ± 25.5, respectively) to 39.7 ± 40.3 and 36.3 ± 20.7 (P = 0.021, and 0.003; n = 5) at 60 min post-SCS, respectively. The intensity thresholds for pUHF-SCS to induce brain and sciatic nerve activations were much higher than the therapeutic intensities and thresholds of conventional low-frequency SCS. CONCLUSIONS Pulsed ultrahigh-frequency spinal cord stimulation inhibited neuropathic pain-related behavior and paw stimulation evoked brain activation through mechanisms distinct from low-frequency SCS. EDITOR’S PERSPECTIVE
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Affiliation(s)
- Chin-Tsang Yang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan; and Department of Leisure Industry and Health Promotion, National Ilan University, Yilan, Taiwan
| | - Yun Guan
- Department of Anesthesiology and Critical Care Medicine, Department of Neurological Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Chih-Cheng Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan; Neuroscience Program of Academia Sinica, Academia Sinica, Taipei, Taiwan; and Taiwan Mouse Clinic, Biomedical Translational Research Center, Academia Sinica, Taipei, Taiwan
| | | | - Kuo-Hsiang Lu
- Kuo-Hsiang Lu, M.S.; Gimer Medical Co., New Taipei City, Taiwan
| | - Chung-Ren Lin
- Department of Anesthesiology, National Cheng Kung University Hospital, Tainan, Taiwan
| | - Bai-Chuang Shyu
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Yeong-Ray Wen
- Pain Management and Research Center, Department of Anesthesiology, China Medical University Hospital, Taichung, Taiwan; and College of Medicine, China Medical University, Taichung, Taiwan
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Effects of remifentanil on the noxiously stimulated somatosensory evoked potentials recorded at the spinal cord in dogs and cats. Res Vet Sci 2023; 158:13-16. [PMID: 36898954 DOI: 10.1016/j.rvsc.2023.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 11/10/2022] [Accepted: 03/01/2023] [Indexed: 03/07/2023]
Abstract
This study assessed the somatosensory evoked potentials (SEPs) in dogs and cats to compare the effect of remifentanil on the action potentials evoked by peripheral noxious stimulation in the spinal cord. Five healthy dogs and five healthy cats underwent general anaesthesia induced with propofol and maintained with isoflurane. Each animals received all dosage of a constant-rate infusion of remifentanil at 0 (control), 0.25, 0.5, 1.0 or 2.0 μg/kg/min. The hair of the dorsal foot of a hind limb was clipped and an intraepidermal stimulation electrode that could selectively stimulate the nociceptive Aδ and C fibres was attached. An electrical stimulus was generated by a portable peripheral nerve testing device. The evoked potentials were recorded by two needle electrodes inserted subcutaneously in the dorsal midline between the lumbar vertebra: L3-L4 and L4-L5. Bimodal waveforms were obtained by electrical stimulation in control dogs and cats. The inhibitory effect of remifentanil was evaluated by comparing the changes in the N1P2 and P2N2 amplitudes. The N1P2 amplitude was depressed by remifentanil in a dose-dependent manner in dogs, but it showed no remifentanil-induced changes in cats. While the P2N2 amplitude was also depressed in a dose-dependent manner in dogs, it showed milder remifentanil-induced effects in cats. The N1P2 and P2N2 amplitudes observed herein are assumed to represent the evoked potentials derived from the Aδ and C fibres, respectively. Thus, the inhibitory effect of remifentanil on nociceptive transmission at the spinal cord was much weaker in cats, especially for transmissions possibly derived from Aδ fibres.
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Kurobe M, Suzuki T. Pain reduction method in recording F-waves from the vastus lateralis muscle. Muscle Nerve 2023; 67:236-238. [PMID: 36576113 DOI: 10.1002/mus.27780] [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: 08/09/2022] [Revised: 12/16/2022] [Accepted: 12/25/2022] [Indexed: 12/29/2022]
Abstract
INTRODUCTION/AIMS Conventional recording of F-waves from the vastus lateralis muscle causes severe pain in some subjects. Thus, we aimed to investigate the effects of the stimulation frequency on pain and F-wave parameters when recording F-waves from this muscle and to develop a method for recording F-waves from the vastus lateralis muscle that causes minimal pain. METHODS The subject's femoral nerve was electrically stimulated at 0.5 or 0.2 Hz 30 times, while F-waves were recorded from the vastus lateralis muscle. Pain intensity was measured immediately using a visual analog scale. In addition, the visual analog scale, F-wave persistence, F-wave latency, and F/M amplitude ratio were compared between F-wave recordings with 0.5-Hz electrical stimulation and those with 0.2-Hz electrical stimulation. RESULTS Eleven healthy men participated in this study. The visual analog scale and F-wave persistence decreased when electrical stimulation at 0.2 Hz was applied compared with electrical stimulation at 0.5 Hz. DISCUSSION Electrical stimulation at 0.5 Hz increased pain due to temporal summation. However, electrical stimulation at 0.2 Hz did not cause temporal summation, suggesting reduced pain and excitability of the alpha motor neuron pool.
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Affiliation(s)
- Masataka Kurobe
- Department of Rehabilitation, Tanabe Central Hospital, Wakayama, Japan.,Department of Clinical Rehabilitation Research, Tanabe Central Hospital, Wakayama, Japan
| | - Toshiaki Suzuki
- Graduate School of Health Sciences, Graduate School of Kansai University of Health Sciences, Osaka, Japan
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Chiu CH, Weng SJ, Yeh SHH, Jhao YT, Chang HF, Huang WS, Cheng CY, Yeh CC, Ma KH. Assessment of the anti-nociceptive effects of fetal ventral mesencephalic tissue allografts in a rat model of hemi-Parkinson's disease using fMRI. Front Aging Neurosci 2022; 14:948848. [PMID: 36466604 PMCID: PMC9716198 DOI: 10.3389/fnagi.2022.948848] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 10/17/2022] [Indexed: 12/04/2023] Open
Abstract
Extensive studies showed increased subjective pain sensitivity in Parkinson's disease (PD), which appeared to be partially reversed by dopaminergic (DA) treatment. Although cell replacement represents an attractive therapeutic strategy, its potential for PD-related hyperalgesia remains unclear. We investigated re-establishment of DA function via allografting exogenic DA cells on pain hypersensitivity in a rat model of PD. We evaluated the anti-nociceptive effects of fetal ventral mesencephalic (rVM) tissue allografts in PD rats after unilateral 6-OHDA-induced toxicity in the medial forebrain bundle. The drug -induced rotation test was used to validate the severity of the nigrostriatal lesion; von Frey and thermal pain tests were employed to evaluate nociceptive function. Nociception-induced cerebral blood volume (CBV) response was measured using a 4.7-T MR system. Finally, the immunohistochemical (IHC) studies were performed and the results were compared with the imaging findings from functional magnetic resonance imaging (fMRI). The grafts significantly improved drug-induced rotation behavior and increased mechanical and thermal nociceptive thresholds in PD rats. The elevation of CBV signals significantly recovered on the grafted striatum, whereas this effect was inhibited by the D2R antagonist eticlopride in each striatum. Quantitative IHC analysis revealed the transplantation markedly increased the numbers of tyrosine hydroxylase immunoreactive cells. Therefore, we concluded transplantation of rVM tissue results in anti-nociceptive effects and improves motor function. Moreover, in vivo CBV response confirmed the key role of D2R-mediated pain modulation. Therefore, we demonstrate fMRI as a reliable imaging index in evaluating the anti-nociceptive therapeutic effects of fetal rVM transplantation in the rat model of PD.
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Affiliation(s)
- Chuang-Hsin Chiu
- Department of Nuclear Medicine, National Defense Medical Center, Tri-Service General Hospital, Taipei, Taiwan
| | - Shao-Ju Weng
- Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan
| | | | - Yun-Ting Jhao
- Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan
| | | | - Wen-Sheng Huang
- Department of Nuclear Medicine, Cheng-Hsin General Hospital, Taipei, Taiwan
| | - Cheng-Yi Cheng
- Department of Nuclear Medicine, National Defense Medical Center, Tri-Service General Hospital, Taipei, Taiwan
| | - Chun-Chang Yeh
- Department of Anesthesiology, National Defense Medical Center, Tri-Service General Hospital, Taipei, Taiwan
| | - Kuo-Hsing Ma
- Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan
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Tøttrup L, Atashzar SF, Farina D, Kamavuako EN, Jensen W. Altered evoked low-frequency connectivity from SI to ACC following nerve injury in rats. J Neural Eng 2021; 18. [PMID: 33957613 DOI: 10.1088/1741-2552/abfeb9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 05/06/2021] [Indexed: 12/11/2022]
Abstract
Objective. Despite decades of research on central processing of pain, there are still several unanswered questions, in particular regarding the brain regions that may contribute to this alerting sensation. Since it is generally accepted that more than one cortical area is responsible for pain processing, there is an increasing focus on the interaction between areas known to be involved.Approach. In this study, we aimed to investigate the bidirectional information flow from the primary somatosensory cortex (SI) to the anterior cingulate cortex (ACC) in an animal model of neuropathic pain.19 rats (nine controls and ten intervention) had an intracortical electrode implanted with six pins in SI and six pins in ACC, and a cuff stimulation electrode around the sciatic nerve. The intervention rats were subjected to the spared nerve injury (SNI) after baseline recordings. Electrical stimulation at three intensities of both noxious and non-noxious stimulation was used to record electrically evoked cortical potentials. To investigate information flow, two connectivity measures were used: phase lag index (PLI) and granger prediction (GP). The rats were anesthetized during the entire study.Main results. Immediately after the intervention (<5 min after intervention), the high frequency (γandγ+) PLI was significantly decreased compared to controls. In the last recording cycle (3-4 h after intervention), the GP increased consistently in the intervention group. Peripheral nerve injury, as a model of neuropathic pain, resulted in an immediate decrease in information flow between SI and ACC, possibly due to decreased sensory input from the injured nerve. Hours after injury, the connectivity between SI and ACC increased, likely indicating hypersensitivity of this pathway.Significance. We have shown that both a directed and non-directed connectivity between SI and ACC approach can be used to show the acute changes resulting from the SNI model.
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Affiliation(s)
- Lea Tøttrup
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - S Farokh Atashzar
- Departments of Electrical and Computer Engineering, and Mechanical and Aerospace Engineering, New York University, New York, NY, USA.,NYU WIRELESS center, New York University (NYU), New York, NY, USA
| | - Dario Farina
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Ernest Nlandu Kamavuako
- Department of Engineering, King's College London, London, United Kingdom.,Université de Kindu, Faculté de Médecine, Département des Sciences de base, Maniema, DR Congo
| | - Winnie Jensen
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
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Claron J, Hingot V, Rivals I, Rahal L, Couture O, Deffieux T, Tanter M, Pezet S. Large-scale functional ultrasound imaging of the spinal cord reveals in-depth spatiotemporal responses of spinal nociceptive circuits in both normal and inflammatory states. Pain 2021; 162:1047-1059. [PMID: 32947542 PMCID: PMC7977620 DOI: 10.1097/j.pain.0000000000002078] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 07/28/2020] [Accepted: 08/20/2020] [Indexed: 12/13/2022]
Abstract
Despite a century of research on the physiology/pathophysiology of the spinal cord in chronic pain condition, the properties of the spinal cord were rarely studied at the large-scale level from a neurovascular point of view. This is mostly due to the limited spatial and/or temporal resolution of the available techniques. Functional ultrasound imaging (fUS) is an emerging neuroimaging approach that allows, through the measurement of cerebral blood volume, the study of brain functional connectivity or functional activations with excellent spatial (100 μm) and temporal (1 msec) resolutions and a high sensitivity. The aim of this study was to increase our understanding of the spinal cord physiology through the study of the properties of spinal hemodynamic response to the natural or electrical stimulation of afferent fibers. Using a combination of fUS and ultrasound localization microscopy, the first step of this study was the fine description of the vascular structures in the rat spinal cord. Then, using either natural or electrical stimulations of different categories of afferent fibers (Aβ, Aδ, and C fibers), we could define the characteristics of the typical hemodynamic response of the rat spinal cord experimentally. We showed that the responses are fiber-specific, located ipsilaterally in the dorsal horn, and that they follow the somatotopy of afferent fiber entries in the dorsal horn and that the C-fiber response is an N-methyl-D-aspartate receptor-dependent mechanism. Finally, fUS imaging of the mesoscopic hemodynamic response induced by natural tactile stimulations revealed a potentiated response in inflammatory condition, suggesting an enhanced response to allodynic stimulations.
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Affiliation(s)
- Julien Claron
- Laboratory of Brain Plasticity, ESPCI Paris, PSL Research University, CNRS UMR 8249, Paris, France
- Physics for Medicine Paris, Inserm, ESPCI Paris, CNRS, PSL Research, University, Paris, France
| | - Vincent Hingot
- Physics for Medicine Paris, Inserm, ESPCI Paris, CNRS, PSL Research, University, Paris, France
| | - Isabelle Rivals
- Equipe de Statistique Appliquée, ESPCI Paris, PSL Research University, CNRS UMRS 1158, Paris, France
| | - Line Rahal
- Laboratory of Brain Plasticity, ESPCI Paris, PSL Research University, CNRS UMR 8249, Paris, France
- Physics for Medicine Paris, Inserm, ESPCI Paris, CNRS, PSL Research, University, Paris, France
| | - Olivier Couture
- Physics for Medicine Paris, Inserm, ESPCI Paris, CNRS, PSL Research, University, Paris, France
| | - Thomas Deffieux
- Physics for Medicine Paris, Inserm, ESPCI Paris, CNRS, PSL Research, University, Paris, France
| | - Mickael Tanter
- Physics for Medicine Paris, Inserm, ESPCI Paris, CNRS, PSL Research, University, Paris, France
| | - Sophie Pezet
- Laboratory of Brain Plasticity, ESPCI Paris, PSL Research University, CNRS UMR 8249, Paris, France
- Physics for Medicine Paris, Inserm, ESPCI Paris, CNRS, PSL Research, University, Paris, France
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D'Elia A, Schiavi S, Soluri A, Massari R, Soluri A, Trezza V. Role of Nuclear Imaging to Understand the Neural Substrates of Brain Disorders in Laboratory Animals: Current Status and Future Prospects. Front Behav Neurosci 2020; 14:596509. [PMID: 33362486 PMCID: PMC7759612 DOI: 10.3389/fnbeh.2020.596509] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 11/23/2020] [Indexed: 12/18/2022] Open
Abstract
Molecular imaging, which allows the real-time visualization, characterization and measurement of biological processes, is becoming increasingly used in neuroscience research. Scintigraphy techniques such as single photon emission computed tomography (SPECT) and positron emission tomography (PET) provide qualitative and quantitative measurement of brain activity in both physiological and pathological states. Laboratory animals, and rodents in particular, are essential in neuroscience research, providing plenty of models of brain disorders. The development of innovative high-resolution small animal imaging systems together with their radiotracers pave the way to the study of brain functioning and neurotransmitter release during behavioral tasks in rodents. The assessment of local changes in the release of neurotransmitters associated with the performance of a given behavioral task is a turning point for the development of new potential drugs for psychiatric and neurological disorders. This review addresses the role of SPECT and PET small animal imaging systems for a better understanding of brain functioning in health and disease states. Brain imaging in rodent models faces a series of challenges since it acts within the boundaries of current imaging in terms of sensitivity and spatial resolution. Several topics are discussed, including technical considerations regarding the strengths and weaknesses of both technologies. Moreover, the application of some of the radioligands developed for small animal nuclear imaging studies is discussed. Then, we examine the changes in metabolic and neurotransmitter activity in various brain areas during task-induced neural activation with special regard to the imaging of opioid, dopaminergic and cannabinoid receptors. Finally, we discuss the current status providing future perspectives on the most innovative imaging techniques in small laboratory animals. The challenges and solutions discussed here might be useful to better understand brain functioning allowing the translation of preclinical results into clinical applications.
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Affiliation(s)
- Annunziata D'Elia
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy.,Section of Biomedical Sciences and Technologies, Department of Science, University "Roma Tre", Rome, Italy
| | - Sara Schiavi
- Section of Biomedical Sciences and Technologies, Department of Science, University "Roma Tre", Rome, Italy
| | - Andrea Soluri
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy
| | - Roberto Massari
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy
| | - Alessandro Soluri
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy
| | - Viviana Trezza
- Section of Biomedical Sciences and Technologies, Department of Science, University "Roma Tre", Rome, Italy
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Tøttrup L, Diaz-Valencia G, Kamavuako EN, Jensen W. Modulation of SI and ACC response to noxious and non-noxious electrical stimuli after the spared nerve injury model of neuropathic pain. Eur J Pain 2020; 25:612-623. [PMID: 33166003 DOI: 10.1002/ejp.1697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 10/14/2020] [Indexed: 11/07/2022]
Abstract
BACKGROUND The current knowledge on the role of SI and ACC in acute pain processing and how these contribute to the development of chronic pain is limited. Our objective was to investigate differences in and modulation of intracortical responses from SI and ACC in response to different intensities of peripheral presumed noxious and non-noxious stimuli in the acute time frame of a peripheral nerve injury in rats. METHODS We applied non-noxious and noxious electrical stimulation pulses through a cuff electrode placed around the sciatic nerve and measured the cortical responses (six electrodes in each cortical area) before and after the spared nerve injury model. RESULTS We found that the peak response correlated with the stimulation intensity and that SI and ACC differed in both amplitude and latency of cortical response. The cortical response to both noxious and non-noxious stimulation showed a trend towards faster processing of non-noxious stimuli in ACC and increased cortical processing of non-noxious stimuli in SI after SNI. CONCLUSIONS We found different responses in SI and ACC to different intensity electrical stimulations based on two features and changes in these features following peripheral nerve injury. We believe that these features may be able to assist to track cortical changes during the chronification of pain in future animal studies. SIGNIFICANCE This study showed distinct cortical processing of noxious and non-noxious peripheral stimuli in SI and ACC. The processing latency in ACC and accumulated spiking activity in SI appeared to be modulated by peripheral nerve injury, which elaborated on the function of these two areas in the processing of nociception.
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Affiliation(s)
- Lea Tøttrup
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Gabriela Diaz-Valencia
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Ernest N Kamavuako
- Department of Engineering, King's College London, London, UK.,Faculté de Médecine, Université de Kindu, Maniema, D.R Congo
| | - Winnie Jensen
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
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11
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McVeigh LG, Perugini AJ, Fehrenbacher JC, White FA, Kacena MA. Assessment, Quantification, and Management of Fracture Pain: from Animals to the Clinic. Curr Osteoporos Rep 2020; 18:460-470. [PMID: 32827293 PMCID: PMC7541703 DOI: 10.1007/s11914-020-00617-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
PURPOSE OF REVIEW Fractures are painful and disabling injuries that can occur due to trauma, especially when compounded with pathologic conditions, such as osteoporosis in older adults. It is well documented that acute pain management plays an integral role in the treatment of orthopedic patients. There is no current therapy available to completely control post-fracture pain that does not interfere with bone healing or have major adverse effects. In this review, we focus on recent advances in the understanding of pain behaviors post-fracture. RECENT FINDINGS We review animal models of bone fracture and the assays that have been developed to assess and quantify spontaneous and evoked pain behaviors, including the two most commonly used assays: dynamic weight bearing and von Frey testing to assess withdrawal from a cutaneous (hindpaw) stimulus. Additionally, we discuss the assessment and quantification of fracture pain in the clinical setting, including the use of numeric pain rating scales, satisfaction with pain relief, and other biopsychosocial factor measurements. We review how pain behaviors in animal models and clinical cases can change with the use of current pain management therapies. We conclude by discussing the use of pain behavioral analyses in assessing potential therapeutic treatment options for addressing acute and chronic fracture pain without compromising fracture healing. There currently is a lack of effective treatment options for fracture pain that reliably relieve pain without potentially interfering with bone healing. Continued development and verification of reliable measurements of fracture pain in both pre-clinical and clinical settings is an essential aspect of continued research into novel analgesic treatments for fracture pain.
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Affiliation(s)
- Luke G McVeigh
- Department of Orthopaedic Surgery, Indiana University School of Medicine, 1130 W. Michigan St, FH 115, Indianapolis, IN, 46202, USA
| | - Anthony J Perugini
- Department of Orthopaedic Surgery, Indiana University School of Medicine, 1130 W. Michigan St, FH 115, Indianapolis, IN, 46202, USA
| | - Jill C Fehrenbacher
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Fletcher A White
- Department of Anesthesia, Indiana University School of Medicine, Indianapolis, IN, USA
- Richard L. Roudebush VA Medical Center, Indianapolis, IN, USA
| | - Melissa A Kacena
- Department of Orthopaedic Surgery, Indiana University School of Medicine, 1130 W. Michigan St, FH 115, Indianapolis, IN, 46202, USA.
- Richard L. Roudebush VA Medical Center, Indianapolis, IN, USA.
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12
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Wang Z, Huang S, Yu X, Li L, Yang M, Liang S, Liu W, Tao J. Altered thalamic neurotransmitters metabolism and functional connectivity during the development of chronic constriction injury induced neuropathic pain. Biol Res 2020; 53:36. [PMID: 32843088 PMCID: PMC7448455 DOI: 10.1186/s40659-020-00303-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 08/08/2020] [Indexed: 11/17/2022] Open
Abstract
Background To investigate the thalamic neurotransmitters and functional connections in the development of chronic constriction injury (CCI)-induced neuropathic pain. Methods The paw withdrawal threshold was measured by mechanical stimulation the right hind paw with the von frey hair in the rats of CCI-induced neuropathic pain. The N-acetylaspartate (NAA) and Glutamate (Glu) in thalamus were detected by magnetic resonance spectrum (MRS) process. The thalamic functional connectivity with other brain regions was scanned by functional magnetic resonance image (fMRI). Results The paw withdrawal threshold of the ipsilateral side showed a noticeable decline during the pathological process. Increased concentrations of Glu and decreased levels of NAA in the thalamus were significantly correlated with mechanical allodynia in the neuropathic pain states. The thalamic regional homogeneity (ReHo) decreased during the process of neuropathic pain. The functional connectivity among the thalamus with the insula and somatosensory cortex were significantly increased at different time points (7, 14, 21 days) after CCI surgery. Conclusion Our study suggests that dynamic changes in thalamic NAA and Glu levels contribute to the thalamic functional connection hyper-excitation during CCI-induced neuropathic pain. Enhanced thalamus-insula functional connection might have a significant effect on the occurrence of neuropathic pain.
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Affiliation(s)
- Zhifu Wang
- College of Integrated Traditional Chinese and Western Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, China
| | - Sheng Huang
- National-Local Joint Engineering Research Center of Rehabilitation Medicine Technology, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, Fujian, China.,Fujian Collaborative Innovation Center for Rehabilitation Technology, Fuzhou, 350122, Fujian, China
| | - Xiangmei Yu
- College of Integrated Traditional Chinese and Western Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, China
| | - Long Li
- National-Local Joint Engineering Research Center of Rehabilitation Medicine Technology, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, Fujian, China.,Fujian Collaborative Innovation Center for Rehabilitation Technology, Fuzhou, 350122, Fujian, China
| | - Minguang Yang
- National-Local Joint Engineering Research Center of Rehabilitation Medicine Technology, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, Fujian, China.,Fujian Collaborative Innovation Center for Rehabilitation Technology, Fuzhou, 350122, Fujian, China
| | - Shengxiang Liang
- National-Local Joint Engineering Research Center of Rehabilitation Medicine Technology, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, Fujian, China.,Fujian Collaborative Innovation Center for Rehabilitation Technology, Fuzhou, 350122, Fujian, China
| | - Weilin Liu
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, China
| | - Jing Tao
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, China.
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13
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Yam MF, Loh YC, Oo CW, Basir R. Overview of Neurological Mechanism of Pain Profile Used for Animal "Pain-Like" Behavioral Study with Proposed Analgesic Pathways. Int J Mol Sci 2020; 21:ijms21124355. [PMID: 32575378 PMCID: PMC7352401 DOI: 10.3390/ijms21124355] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 05/06/2020] [Accepted: 05/11/2020] [Indexed: 12/16/2022] Open
Abstract
Pain is the most common sensation installed in us naturally which plays a vital role in defending us against severe harm. This neurological mechanism pathway has been one of the most complex and comprehensive topics but there has never been an elaborate justification of the types of analgesics that used to reduce the pain sensation through which specific pathways. Of course, there have been some answers to curbing of pain which is a lifesaver in numerous situations-chronic and acute pain conditions alike. This has been explored by scientists using pain-like behavioral study methodologies in non-anesthetized animals since decades ago to characterize the analgesic profile such as centrally or peripherally acting drugs and allowing for the development of analgesics. However, widely the methodology is being practiced such as the tail flick/Hargreaves test and Von Frey/Randall-Selitto tests which are stimulus-evoked nociception studies, and there has rarely been a complete review of all these methodologies, their benefits and its downside coupled with the mechanism of the action that is involved. Thus, this review solely focused on the complete protocol that is being adapted in each behavioral study methods induced by different phlogogenic agents, the different assessment methods used for phasic, tonic and inflammatory pain studies and the proposed mechanism of action underlying each behavioral study methodology for analgesic drug profiling. It is our belief that this review could significantly provide a concise idea and improve our scientists' understanding towards pain management in future research.
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Affiliation(s)
- Mun Fei Yam
- Department of Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Malaysia
- Department of Pharmacology, School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden 11800, Malaysia;
| | - Yean Chun Loh
- Department of Organic Chemistry, School of Chemical Sciences, Universiti Sains Malaysia, Minden 11800, Malaysia;
- Correspondence: (Y.C.L.); (R.B.); Tel.: +60-46536018 (Y.C.L.); +60-389472448 (R.B.)
| | - Chuan Wei Oo
- Department of Organic Chemistry, School of Chemical Sciences, Universiti Sains Malaysia, Minden 11800, Malaysia;
| | - Rusliza Basir
- Department of Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Malaysia
- Correspondence: (Y.C.L.); (R.B.); Tel.: +60-46536018 (Y.C.L.); +60-389472448 (R.B.)
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14
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Abstract
Pain-related diseases are the top leading causes of life disability. Identifying brain regions involved in persistent neuronal changes will provide new insights for developing efficient chronic pain treatment. Here, we showed that anterior nucleus of paraventricular thalamus (PVA) plays an essential role in the development of mechanical hyperalgesia in neuropathic and inflammatory pain models in mice. Increase in c-Fos, phosphorylated extracellular signal-regulated kinase, and hyperexcitability of PVA neurons were detected in hyperalgesic mice. Direct activation of PVA neurons using optogenetics and pharmacological approaches were sufficient to induce persistent mechanical hyperalgesia in naive animals. Conversely, inhibition of PVA neuronal activity using DREADDs (designer receptors exclusively activated by designer drugs) or inactivation of PVA extracellular signal-regulated kinase at the critical time window blunted mechanical hyperalgesia in chronic pain models. At the circuitry level, PVA received innervation from central nucleus of amygdala, a known pain-associated locus. As a result, activation of right central nucleus of amygdala with blue light was enough to induce persistent mechanical hyperalgesia. These findings support the idea that targeting PVA can be a potential therapeutic strategy for pain relief.
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15
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Chen CC, Chang C, Hsu YH, Peng YJ, Lee HS, Huang GS. fMRI indicates cortical activation through TRPV1 modulation during acute gouty attacks. Sci Rep 2019; 9:12348. [PMID: 31451732 PMCID: PMC6710282 DOI: 10.1038/s41598-019-48656-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 08/07/2019] [Indexed: 11/09/2022] Open
Abstract
Gout is one of the most painful disease conditions. The central mechanism of pain processing in this condition remains elusive. Cerebral blood volume (CBV) responses are faithful correlates of brain activity changes; the application of CBV-weighted functional magnetic resonance imaging (fMRI) may shed light on the issue of interest. Transient receptor potential vanilloid 1 (TRPV1) is a critical ion channel expressed both peripherally in nociceptors and centrally in the brain. Whether TRPV1 plays a critical role in gout pain was also explored. Results showed that, in rats with gouty arthritis, noxious stimulation induced CBV increases in the primary somatosensory cortex and thalamus. These increases were correlated with up-regulated TRPV1 protein expression and pain behavior. Selective blockage of central TRPV1 channel activity by intrathecal administration of AMG9810 reversed the induced pain, and abolished the induced CBV increase in thalamocortical regions. The findings support that TRPV1 activation in the central pain pathway is crucial to the augmentation of pain in gouty conditions. This new information supports the development of TRPV1-based drugs for treating gout pain, while fMRI can be useful for repeated evaluation of brain activity changes induced by gout.
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Affiliation(s)
- Chiao-Chi Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Chen Chang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.
| | - Yi-Hua Hsu
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Yi-Jen Peng
- Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Herng-Sheng Lee
- Department of Pathology and Laboratory Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Guo-Shu Huang
- Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan. .,Department of Medical Research, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
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16
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Spontaneous Cingulate High-Current Spikes Signal Normal and Pathological Pain States. J Neurosci 2019; 39:5128-5142. [PMID: 31023834 DOI: 10.1523/jneurosci.2590-18.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 04/08/2019] [Accepted: 04/15/2019] [Indexed: 01/29/2023] Open
Abstract
Prominent 7-12 Hz oscillations in frontal cortical networks in rats have been reported. However, the mechanism of generation and the physiological function of this brain rhythm have not yet been clarified. Multichannel extracellular field potentials of the ACC were recorded and analyzed using the current source density method in halothane-anesthetized rats. Spontaneous high-current spikes (HCSs) were localized in the deep part of layer II/III and upper part of layer V of the ACC. The frequency of HCSs in the ACC was 7-12 Hz, with an amplitude of 6.5 ± 0.76 mV/mm2 and duration of 55.24 ± 2.43 ms. The power density significantly decreased (84.56 ± 6.93%, p < 0.05, t test) after pinching the hindpaw and significantly increased (149.28 ± 15.96%) after treatment with morphine. The suppressive effect of pinching was reversed by naloxone (0.7 mg/kg, i.p.). HCSs coincided with initiation of the depolarization of cingulate neurons and remained in a depolarized upstate. The occurrence of cingulate HCSs was persistently preceded by a hyperpolarization phase and a burst of multiunit spike activity in the medial dorsal thalamic nucleus. Spontaneous field-potential oscillations changed from 10 Hz to a lower band (i.e., ∼7.5 Hz) when a central poststroke pain condition was induced. The central poststroke pain group had a higher average coherence coefficient compared with the control group. Our results indicate that spontaneous cingulate cortical HCSs could be initiated by thalamocortical synaptic inputs from the medial dorsal thalamic nucleus and maintained by intracortical neuronal upstate mechanisms in physiological and pathological pain states.SIGNIFICANCE STATEMENT This study elucidated the mechanism of generation and physiological function of prominent 7-12 Hz frequency oscillations in frontal cortical networks in rats. Spontaneous cingulate cortical high-current spikes in anesthetized rats could be initiated by thalamocortical synaptic inputs from the medial dorsal thalamic nucleus and maintained by intracortical neuronal upstate mechanisms. Suppression of the anterior cingulate cortex-filtered EEG during noxious stimulation may have resulted from the desynchronization of high-current spikes in the ACC. The enhancement of fast Fourier transform power after a systemic morphine injection suggested that the opioid system may play an important role in synchronizing cingulate cortical neuronal networks. Spontaneous cingulate high-current spikes may also play an important role in thalamocortical dysrhythmia in central poststroke pain.
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17
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Lu PL, Tsai ML, Jaw FS, Yen CT. Distributions of different types of nociceptive neurons in thalamic mediodorsal nuclei of anesthetized rats. J Physiol Sci 2019; 69:387-397. [PMID: 30604289 PMCID: PMC10716950 DOI: 10.1007/s12576-018-00656-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 12/18/2018] [Indexed: 12/25/2022]
Abstract
Mediodorsal thalamic nucleus (MD) is a critical relay of nociception. This study recorded responses of MD neurons to noxious mechanical and thermal stimuli in isoflurane anesthetized rats. We found the threshold of noxious mechanical stimulation was 141 gw and that of noxious heat stimulation was 46 °C. A significantly higher percentage of noxious inhibitory neurons were found in the medial and central part of the MD, whereas a higher percentage of noxious excitatory neurons were found in the lateral part of the MD and adjacent intralaminar nuclei. The differential distribution of excitatory and inhibitory neurons implies functional differentiation between the medial and lateral part of the MD in nociception processing. Furthermore, by an analysis of the stimulus-response function (SRF), we found 80% of these excitatory neurons had a step-function or hat-shape-like SRF. This suggests that most of the MD neurons may serve as a system to distinguish innocuous versus noxious stimuli.
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Affiliation(s)
- Pen-Li Lu
- Institute of Biomedical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taibei, 10617, Taiwan
| | - Meng-Li Tsai
- Department of Biomechatronic Engineering, National Ilan University, 1, Sec. 1, Shen-Lung Road, I-Lan, 26047, Taiwan
| | - Fu-Shan Jaw
- Institute of Biomedical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taibei, 10617, Taiwan
| | - Chen-Tung Yen
- Department of Life Science, National Taiwan University, 1 Roosevelt Road, Section 4, Taibei, 10617, Taiwan.
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18
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Chang WJ, Buscemi V, Liston MB, McAuley JH, Hodges PW, Schabrun SM. Sensorimotor Cortical Activity in Acute Low Back Pain: A Cross-Sectional Study. THE JOURNAL OF PAIN 2019; 20:819-829. [PMID: 30660764 DOI: 10.1016/j.jpain.2019.01.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 12/04/2018] [Accepted: 01/16/2019] [Indexed: 12/11/2022]
Abstract
Sensorimotor cortical activity is altered in both the immediate acute and chronic stages of musculoskeletal pain. However, these changes are opposite, with decreased cortical activity reported in experimentally induced acute pain (lasting minutes to hours), and increased cortical activity in chronic, clinical pain (lasting >6 months). It is unknown whether sensorimotor cortical activity is altered in acute, clinical musculoskeletal pain (lasting <4 weeks). In 36 individuals with acute, nonspecific, clinical low back pain (LBP) and 36 age- and sex-matched, pain-free controls, we investigated the processing of non-noxious afferent inputs using sensory evoked potentials (SEPs), as well as corticomotor excitability and organization of the primary motor cortex using transcranial magnetic stimulation. Processing of non-noxious sensory inputs was lower (smaller area of the N80-N150-P260 SEP complex) in acute LBP (F1,70 = 45.28, P < .01). The examination of specific SEP components revealed a smaller area of the N150 and P260 SEP components in acute LBP, although interindividual variability was high. Motor cortical map volume was lower in acute LBP (F1,70 = 5.61, P = .02). These findings demonstrate that acute LBP is characterized by lower sensorimotor cortical activity at the group level. However, individual variation was high, suggesting individual adaptation of cortical plasticity in acute pain. PERSPECTIVE: This is the first study to examine sensorimotor cortical activity in the acute stage of clinical LBP. This information is critical for understanding the neurophysiology of acute LBP.
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Affiliation(s)
- Wei-Ju Chang
- School of Science and Health, Western Sydney University, Sydney, New South Wales, Australia
| | - Valentina Buscemi
- School of Science and Health, Western Sydney University, Sydney, New South Wales, Australia
| | - Matthew B Liston
- Centre for Human and Applied Physiological Sciences, Faculty of Life Sciences and Medicine, Shepherd's House, King's College London, UK
| | - James H McAuley
- Neuroscience Research Australia (NeuRA), Sydney, New South Wales, Australia
| | - Paul W Hodges
- The University of Queensland, School of Health and Rehabilitation Sciences, St Lucia, Queensland, Australia
| | - Siobhan M Schabrun
- Neuroscience Research Australia (NeuRA), Sydney, New South Wales, Australia..
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19
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Pautrat A, Rolland M, Barthelemy M, Baunez C, Sinniger V, Piallat B, Savasta M, Overton PG, David O, Coizet V. Revealing a novel nociceptive network that links the subthalamic nucleus to pain processing. eLife 2018; 7:36607. [PMID: 30149836 PMCID: PMC6136891 DOI: 10.7554/elife.36607] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 08/06/2018] [Indexed: 12/13/2022] Open
Abstract
Pain is a prevalent symptom of Parkinson's disease, and is effectively treated by deep brain stimulation of the subthalamic nucleus (STN). However, the link between pain and the STN remains unclear. In the present work, using in vivo electrophysiology in rats, we report that STN neurons exhibit complex tonic and phasic responses to noxious stimuli. We also show that nociception is altered following lesions of the STN, and characterize the role of the superior colliculus and the parabrachial nucleus in the transmission of nociceptive information to the STN, physiologically from both structures and anatomically in the case of the parabrachial nucleus. We show that STN nociceptive responses are abnormal in a rat model of PD, suggesting their dependence on the integrity of the nigrostriatal dopaminergic system. The STN-linked nociceptive network that we reveal is likely to be of considerable clinical importance in neurological diseases involving a dysfunction of the basal ganglia.
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Affiliation(s)
- Arnaud Pautrat
- Inserm, Grenoble, France.,Grenoble Institute of Neurosciences, Université Grenoble Alpes, Grenoble, France
| | - Marta Rolland
- Inserm, Grenoble, France.,Grenoble Institute of Neurosciences, Université Grenoble Alpes, Grenoble, France
| | - Margaux Barthelemy
- Inserm, Grenoble, France.,Grenoble Institute of Neurosciences, Université Grenoble Alpes, Grenoble, France
| | - Christelle Baunez
- Institut de Neurosciences de la Timone, Aix-Marseille Université, Marseille, France
| | - Valérie Sinniger
- Grenoble Institute of Neurosciences, Université Grenoble Alpes, Grenoble, France.,Service d'Hépato-Gastroentérologie, CHU Grenoble Alpes, Grenoble, France
| | - Brigitte Piallat
- Inserm, Grenoble, France.,Grenoble Institute of Neurosciences, Université Grenoble Alpes, Grenoble, France
| | - Marc Savasta
- Inserm, Grenoble, France.,Grenoble Institute of Neurosciences, Université Grenoble Alpes, Grenoble, France
| | - Paul G Overton
- Department of Psychology, University of Sheffield, Sheffield, United Kingdom
| | - Olivier David
- Inserm, Grenoble, France.,Grenoble Institute of Neurosciences, Université Grenoble Alpes, Grenoble, France
| | - Veronique Coizet
- Inserm, Grenoble, France.,Grenoble Institute of Neurosciences, Université Grenoble Alpes, Grenoble, France
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20
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Paquette T, Jeffrey-Gauthier R, Leblond H, PichÉ M. Functional Neuroimaging of Nociceptive and Pain-Related Activity in the Spinal Cord and Brain: Insights From Neurovascular Coupling Studies. Anat Rec (Hoboken) 2018; 301:1585-1595. [PMID: 29752872 DOI: 10.1002/ar.23854] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 03/22/2018] [Accepted: 03/31/2018] [Indexed: 12/12/2022]
Abstract
Spinal cord and brain processes underlie pain perception, which produces systemic cardiovascular changes. In turn, the autonomic nervous system regulates vascular function in the spinal cord and brain in order to adapt to these systemic changes, while neuronal activity induces local vascular changes. Thus, autonomic regulation and pain processes in the brain and spinal cord are tightly linked and interrelated. The objective of this topical review is to discuss work on neurovascular coupling during nociceptive processing in order to highlight supporting evidence and limitations for the use of cerebral and spinal fMRI to investigate pain mechanisms and spinal nociceptive processes. Work on functional neuroimaging of pain is presented and discussed in relation to available neurovascular coupling studies and related issues. Perspectives on future work are also discussed with an emphasis on differences between the brain and the spinal cord and on different approaches that may be useful to improve current methods, data analyses and interpretation. In summary, this review highlights the lack of data on neurovascular coupling during nociceptive stimulation and indicates that hemodynamic and BOLD responses measured with fMRI may be biased by nonspecific vascular changes. Future neuroimaging studies on nociceptive and pain-related processes would gain further understanding of neurovascular coupling in the brain and spinal cord and should take into account the effects of systemic vascular changes that may affect hemodynamic responses. Anat Rec, 301:1585-1595, 2018. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Thierry Paquette
- Department of Chiropractic, Université du Québec à Trois-Rivières, Trois-Rivières, Canada.,CogNAC Research Group, Université du Québec à Trois-Rivières, Trois-Rivières, Canada.,Department of Anatomy, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
| | - Renaud Jeffrey-Gauthier
- Department of Chiropractic, Université du Québec à Trois-Rivières, Trois-Rivières, Canada.,CogNAC Research Group, Université du Québec à Trois-Rivières, Trois-Rivières, Canada.,Department of Anatomy, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
| | - Hugues Leblond
- CogNAC Research Group, Université du Québec à Trois-Rivières, Trois-Rivières, Canada.,Department of Anatomy, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
| | - Mathieu PichÉ
- Department of Chiropractic, Université du Québec à Trois-Rivières, Trois-Rivières, Canada.,CogNAC Research Group, Université du Québec à Trois-Rivières, Trois-Rivières, Canada
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21
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Slavin KV, Yin D, Rasskazoff S. Peripheral Nerve Stimulation for Facial Pain. Neuromodulation 2018. [DOI: 10.1016/b978-0-12-805353-9.00058-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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22
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Nagakubo D, Hamamoto Y, Hasegawa D, Kamata M, Iizuka T, Muta K, Fujita N, Nakagawa T, Nishimura R. Functional MRI-based identification of brain regions activated by mechanical noxious stimulation and modulatory effect of remifentanil in cats. Res Vet Sci 2017; 114:444-449. [PMID: 28772233 DOI: 10.1016/j.rvsc.2017.07.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 06/10/2017] [Accepted: 07/21/2017] [Indexed: 12/18/2022]
Abstract
This study was conducted to identify the brain regions corresponding to mechanical noxious stimulation in cats using functional magnetic resonance imaging (fMRI) and to investigate the modulatory effect of remifentanil on the activation of these regions. Six healthy cats were anesthetized using a constant-rate infusion of alfaxalone. Cats were allocated to one of three treatment groups: remifentanil 0 (saline), 0.25, and 0.5μg/kg/min. A 3.0-T MRI unit was used to collect fMRI data. During the fMRI scanning, mechanical noxious stimulation was applied by tail clamping. The brain regions activated by the stimulation were identified based on blood oxygenation level-dependent (BOLD) responses. The modulatory effects of remifentanil were evaluated using a region of interest (ROI) analysis comparing signal changes in each brain region. Increased activity from noxious stimulation was observed in the somatosensory area (the postcruciatus gyrus, the anterior part of the marginalis gyrus, and the anterior part of the ectomarginalis gyrus), the parietal association area (the middle part of the marginalis gyrus and the middle part of the ectomarginalis gyrus), the cingulate cortex, the hippocampus, and the cerebellum. The results of the ROI analysis indicated that activations in the somatosensory area, the cingulate cortex, the hippocampus, and the cerebellum were significantly modulated (P<0.05) by remifentanil. In cats, activation patterns evoked by mechanical noxious stimulation were observed in several brain regions thought to be involved in various aspects of pain processing, including sensory discrimination and integration, affect, and motor response. These brain responses were modulated by remifentanil.
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Affiliation(s)
- Dai Nagakubo
- Laboratory of Veterinary Surgery, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yuji Hamamoto
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, Tokyo 180-8602, Japan
| | - Daisuke Hasegawa
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, Tokyo 180-8602, Japan
| | - Masatoshi Kamata
- Veterinary Medical Center, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Tomoya Iizuka
- Veterinary Medical Center, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Kanako Muta
- Laboratory of Veterinary Surgery, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Naoki Fujita
- Laboratory of Veterinary Surgery, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Takayuki Nakagawa
- Laboratory of Veterinary Surgery, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Ryohei Nishimura
- Laboratory of Veterinary Surgery, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
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23
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Cha M, Chae Y, Bai SJ, Lee BH. Spatiotemporal changes of optical signals in the somatosensory cortex of neuropathic rats after electroacupuncture stimulation. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017; 17:33. [PMID: 28068994 PMCID: PMC5223459 DOI: 10.1186/s12906-016-1510-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2016] [Accepted: 12/01/2016] [Indexed: 12/20/2022]
Abstract
Background Peripheral nerve injury causes physiological changes in primary afferent neurons. Neuropathic pain associated with peripheral nerve injuries may reflect changes in the excitability of the nervous system, including the spinothalamic tract. Current alternative medical research indicates that acupuncture stimulation has analgesic effects in various pain symptoms. However, activation changes in the somatosensory cortex of the brain by acupuncture stimulation remain poorly understood. The present study was conducted to monitor the changes in cortical excitability, using optical imaging with voltage-sensitive dye (VSD) in neuropathic rats after electroacupuncture (EA) stimulation. Methods Male Sprague–Dawley rats were divided into three groups: control (intact), sham injury, and neuropathic pain rats. Under pentobarbital anesthesia, rats were subjected to nerve injury with tight ligation and incision of the tibial and sural nerves in the left hind paw. For optical imaging, the rats were re-anesthetized with urethane, and followed by craniotomy. The exposed primary somatosensory cortex (S1) was stained with VSD for one hour. Optical signals were recorded from the S1 cortex, before and after EA stimulation on Zusanli (ST36) and Yinlingquan (SP9). Results After peripheral stimulation, control and sham injury rats did not show significant signal changes in the S1 cortex. However, inflamed and amplified neural activities were observed in the S1 cortex of nerve-injured rats. Furthermore, the optical signals and region of activation in the S1 cortex were reduced substantially after EA stimulation, and recovered in a time-dependent manner. The peak fluorescence intensity was significantly reduced until 90 min after EA stimulation (Pre-EA: 0.25 ± 0.04 and Post-EA 0 min: 0.01 ± 0.01), and maximum activated area was also significantly attenuated until 60 min after EA stimulation (Pre-EA: 37.2 ± 1.79 and Post-EA 0 min: 0.01 ± 0.10). Conclusion Our results indicate that EA stimulation has inhibitory effects on excitatory neuronal signaling in the S1 cortex, caused by noxious stimulation in neuropathic pain. These findings suggest that EA stimulation warrants further study as a potential adjuvant modulation of neuropathic pain.
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Pawela CP, Kramer JM, Hogan QH. Dorsal root ganglion stimulation attenuates the BOLD signal response to noxious sensory input in specific brain regions: Insights into a possible mechanism for analgesia. Neuroimage 2016; 147:10-18. [PMID: 27876655 DOI: 10.1016/j.neuroimage.2016.11.046] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 10/26/2016] [Accepted: 11/17/2016] [Indexed: 12/26/2022] Open
Abstract
Targeted dorsal root ganglion (DRG) electrical stimulation (i.e. ganglionic field stimulation - GFS) is an emerging therapeutic approach to alleviate chronic pain. Here we describe blood oxygen-level dependent (BOLD) functional magnetic resonance imaging (fMRI) responses to noxious hind-limb stimulation in a rat model that replicates clinical GFS using an electrode implanted adjacent to the DRG. Acute noxious sensory stimulation in the absence of GFS caused robust BOLD fMRI response in brain regions previously associated with sensory and pain-related response, such as primary/secondary somatosensory cortex, retrosplenial granular cortex, thalamus, caudate putamen, nucleus accumbens, globus pallidus, and amygdala. These regions differentially demonstrated either positive or negative correlation to the acute noxious stimulation paradigm, in agreement with previous rat fMRI studies. Therapeutic-level GFS significantly attenuated the global BOLD response to noxious stimulation in these regions. This BOLD signal attenuation persisted for 20minutes after the GFS was discontinued. Control experiments in sham-operated animals showed that the attenuation was not due to the effect of repetitive noxious stimulation. Additional control experiments also revealed minimal BOLD fMRI response to GFS at therapeutic intensity when presented in a standard block-design paradigm. High intensity GFS produced a BOLD signal map similar to acute noxious stimulation when presented in a block-design. These findings are the first to identify the specific brain region responses to neuromodulation at the DRG level and suggest possible mechanisms for GFS-induced treatment of chronic pain.
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Affiliation(s)
- Christopher P Pawela
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI, USA.
| | | | - Quinn H Hogan
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, USA
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Brain Network Response to Acupuncture Stimuli in Experimental Acute Low Back Pain: An fMRI Study. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:210120. [PMID: 26161117 PMCID: PMC4487721 DOI: 10.1155/2015/210120] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 05/02/2015] [Accepted: 05/05/2015] [Indexed: 12/30/2022]
Abstract
Most neuroimaging studies have demonstrated that acupuncture can significantly modulate brain activation patterns in healthy subjects, while only a few studies have examined clinical pain. In the current study, we combined an experimental acute low back pain (ALBP) model and functional magnetic resonance imaging (fMRI) to explore the neural mechanisms of acupuncture analgesia. All ALBP subjects first underwent two resting state fMRI scans at baseline and during a painful episode and then underwent two additional fMRI scans, once during acupuncture stimulation (ACUP) and once during tactile stimulation (SHAM) pseudorandomly, at the BL40 acupoint. Our results showed that, compared with the baseline, the pain state had higher regional homogeneity (ReHo) values in the pain matrix, limbic system, and default mode network (DMN) and lower ReHo values in frontal gyrus and temporal gyrus; compared with the OFF status, ACUP yielded broad deactivation in subjects, including nearly all of the limbic system, pain status, and DMN, and also evoked numerous activations in the attentional and somatosensory systems; compared with SHAM, we found that ACUP induced more deactivations and fewer activations in the subjects. Multiple brain networks play crucial roles in acupuncture analgesia, suggesting that ACUP exceeds a somatosensory-guided mind-body therapy for ALBP.
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Hegedűs N, Laszy J, Gyertyán I, Kocsis P, Gajári D, Dávid S, Deli L, Pozsgay Z, Tihanyi K. Scopolamine provocation-based pharmacological MRI model for testing procognitive agents. J Psychopharmacol 2015; 29:447-55. [PMID: 25586394 DOI: 10.1177/0269881114565652] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
There is a huge unmet need to understand and treat pathological cognitive impairment. The development of disease modifying cognitive enhancers is hindered by the lack of correct pathomechanism and suitable animal models. Most animal models to study cognition and pathology do not fulfil either the predictive validity, face validity or construct validity criteria, and also outcome measures greatly differ from those of human trials. Fortunately, some pharmacological agents such as scopolamine evoke similar effects on cognition and cerebral circulation in rodents and humans and functional MRI enables us to compare cognitive agents directly in different species. In this paper we report the validation of a scopolamine based rodent pharmacological MRI provocation model. The effects of deemed procognitive agents (donepezil, vinpocetine, piracetam, alpha 7 selective cholinergic compounds EVP-6124, PNU-120596) were compared on the blood-oxygen-level dependent responses and also linked to rodent cognitive models. These drugs revealed significant effect on scopolamine induced blood-oxygen-level dependent change except for piracetam. In the water labyrinth test only PNU-120596 did not show a significant effect. This provocational model is suitable for testing procognitive compounds. These functional MR imaging experiments can be paralleled with human studies, which may help reduce the number of false cognitive clinical trials.
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Affiliation(s)
- Nikolett Hegedűs
- Preclinical Imaging Centre, Gedeon Richter Plc, Budapest, Hungary
| | - Judit Laszy
- Department of Behavioural Pharmacology, Gedeon Richter Plc, Budapest, Hungary
| | - István Gyertyán
- Department of Behavioural Pharmacology, Gedeon Richter Plc, Budapest, Hungary
| | - Pál Kocsis
- Preclinical Imaging Centre, Gedeon Richter Plc, Budapest, Hungary
| | - Dávid Gajári
- Preclinical Imaging Centre, Gedeon Richter Plc, Budapest, Hungary
| | - Szabolcs Dávid
- Preclinical Imaging Centre, Gedeon Richter Plc, Budapest, Hungary
| | - Levente Deli
- Preclinical Imaging Centre, Gedeon Richter Plc, Budapest, Hungary
| | - Zsófia Pozsgay
- Preclinical Imaging Centre, Gedeon Richter Plc, Budapest, Hungary
| | - Károly Tihanyi
- Preclinical Imaging Centre, Gedeon Richter Plc, Budapest, Hungary
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Specificity of hemodynamic brain responses to painful stimuli: a functional near-infrared spectroscopy study. Sci Rep 2015; 5:9469. [PMID: 25820289 PMCID: PMC4377554 DOI: 10.1038/srep09469] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 03/04/2015] [Indexed: 12/02/2022] Open
Abstract
Assessing pain in individuals not able to communicate (e.g. infants, under surgery, or following stroke) is difficult due to the lack of non-verbal objective measures of pain. Near-infrared spectroscopy (NIRS) being a portable, non-invasive and inexpensive method of monitoring cerebral hemodynamic activity has the potential to provide such a measure. Here we used functional NIRS to evaluate brain activation to an innocuous and a noxious electrical stimulus on healthy human subjects (n = 11). For both innocuous and noxious stimuli, we observed a signal change in the primary somatosensory cortex contralateral to the stimulus. The painful and non-painful stimuli can be differentiated based on their signal size and profile. We also observed that repetitive noxious stimuli resulted in adaptation of the signal. Furthermore, the signal was distinguishable from a skin sympathetic response to pain that tended to mask it. Our results support the notion that functional NIRS has a potential utility as an objective measure of pain.
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Kaka U, Hui Cheng C, Meng GY, Fakurazi S, Kaka A, Behan AA, Ebrahimi M. Electroencephalographic changes associated with antinociceptive actions of lidocaine, ketamine, meloxicam, and morphine administration in minimally anaesthetized dogs. BIOMED RESEARCH INTERNATIONAL 2015; 2015:305367. [PMID: 25695060 PMCID: PMC4324106 DOI: 10.1155/2015/305367] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 11/02/2014] [Accepted: 11/04/2014] [Indexed: 12/24/2022]
Abstract
Effects of ketamine and lidocaine on electroencephalographic (EEG) changes were evaluated in minimally anaesthetized dogs, subjected to electric stimulus. Six dogs were subjected to six treatments in a crossover design with a washout period of one week. Dogs were subjected to intravenous boluses of lidocaine 2 mg/kg, ketamine 3 mg/kg, meloxicam 0.2 mg/kg, morphine 0.2 mg/kg and loading doses of lidocaine 2 mg/kg followed by continuous rate infusion (CRI) of 50 and 100 mcg/kg/min, and ketamine 3 mg/kg followed by CRI of 10 and 50 mcg/kg/min. Electroencephalogram was recorded during electrical stimulation prior to any drug treatment (before treatment) and during electrical stimulation following treatment with the drugs (after treatment) under anaesthesia. Anaesthesia was induced with propofol and maintained with halothane at a stable concentration between 0.85 and 0.95%. Pretreatment median frequency was evidently increased (P < 0.05) for all treatment groups. Lidocaine, ketamine, and morphine depressed the median frequency resulting from the posttreatment stimulation. The depression of median frequency suggested evident antinociceptive effects of these treatments in dogs. It is therefore concluded that lidocaine and ketamine can be used in the analgesic protocol for the postoperative pain management in dogs.
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Affiliation(s)
- Ubedullah Kaka
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
- Faculty of Animal Husbandry & Veterinary Sciences, Sindh Agriculture University Tandojam, Sindh 70060, Pakistan
| | - Chen Hui Cheng
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Goh Yong Meng
- Department of Veterinary Preclinical Sciences, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
- Institutes of Tropical Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Sharida Fakurazi
- Laboratory of Vaccines and Immunotherapeutics, Institute of Bioscience, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
- Department of Human Anatomy, Faculty of Medicine and Health Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Asmatullah Kaka
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
- Faculty of Animal Husbandry & Veterinary Sciences, Sindh Agriculture University Tandojam, Sindh 70060, Pakistan
| | - Atique Ahmed Behan
- Faculty of Animal Husbandry & Veterinary Sciences, Sindh Agriculture University Tandojam, Sindh 70060, Pakistan
- Department of Animal Sciences, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Mahdi Ebrahimi
- Department of Veterinary Preclinical Sciences, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
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Zhang SS, Wu W, Liu ZP, Huang GZ, Guo SG, Yang JM. Altered regional homogeneity in experimentally induced low back pain: a resting-state fMRI study. J Neuroeng Rehabil 2014; 11:115. [PMID: 25080831 PMCID: PMC4237877 DOI: 10.1186/1743-0003-11-115] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2013] [Accepted: 07/21/2014] [Indexed: 11/22/2022] Open
Abstract
Background Functional imaging studies have indicated that patients with low back pain can have significant reductions in cerebral cortex grey matter. However, the mechanisms governing the nociceptive pathways in the human brain are unclear. The aim of this study was to use functional magnetic resonance imaging (fMRI) and regional homogeneity (ReHo) to investigate changes in resting-state brain activity in subjects that experienced experimentally induced low back pain. Methods Healthy subjects (n = 15) underwent fMRI (3.0 T) at baseline and during painful stimulation (intramuscular injection of 3% hypertonic saline). Results Compared to the scans conducted at baseline, scans conducted during experimentally induced low back pain showed increased ReHo on the right side in the medial prefrontal cortex, precuneus, insula, parahippocampal gyrus and cerebellum (posterior lobe), but decreased ReHo in the primary somatosensory cortex, anterior cingulate cortex and parahippocampal gyrus on the left side. The right inferior parietal lobule also showed a decreased ReHo (P < 0.05, cluster threshold ≥10). Conclusions These findings suggest that abnormally spontaneous resting-state activity in some brain regions may be associated with pain processing. These changes in neural activity may contribute to the recognition, execution, memory and emotional processing of acute low back pain.
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Affiliation(s)
| | - Wen Wu
- Department of Rehabilitation Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, People's Republic of China.
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Non-noxious skin stimulation activates the nucleus basalis of Meynert and promotes NGF secretion in the parietal cortex via nicotinic ACh receptors. J Physiol Sci 2014; 64:253-60. [PMID: 24801530 PMCID: PMC4070488 DOI: 10.1007/s12576-014-0313-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 03/20/2014] [Indexed: 02/01/2023]
Abstract
The effects of non-noxious skin stimulation on nerve growth factor (NGF) secretion in the parietal cortex were examined in anesthetized rats. Innocuous skin stimulation was delivered to the left hindlimb with a soft-hair brush. Extracellular NGF in the right parietal cortex was collected by microdialysis methods using a protein-permeable probe and was measured using an enzyme-linked immune-sorbent assay. Brushing produced a significant increase in extracellular NGF levels. This NGF response was not observed in rats pretreated with a nicotinic ACh receptor (nAChR) antagonist mecamylamine. We further examined whether brushing could activate the basal forebrain nucleus (nucleus basalis of Meynert, NBM), which is the main source of cholinergic fibers in the cerebral cortex, by means of functional MRI. The blood oxygen level-dependent signal in the right NBM was significantly higher during brushing compared to baseline. The results suggest that non-noxious skin stimulation activates NBM and promotes NGF secretion in the parietal cortex via nAChRs.
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Lu YF, Wang Y, He Y, Zhang FK, He T, Wang RR, Chen XF, Yang F, Gong KR, Chen J. Spatial and temporal plasticity of synaptic organization in anterior cingulate cortex following peripheral inflammatory pain: multi-electrode array recordings in rats. Neurosci Bull 2014; 30:1-20. [PMID: 23686522 PMCID: PMC5561851 DOI: 10.1007/s12264-013-1344-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 04/19/2013] [Indexed: 12/23/2022] Open
Abstract
To explore whether experiencing inflammatory pain has an impact upon intracortical synaptic organization, the planar multi-electrode array (MEA) technique and 2-dimensional current source density (2D-CSD) imaging were used in slice preparations of the anterior cingulate cortex (ACC) from rats. Synaptic activity across different layers of the ACC was evoked by deep layer stimulation through one electrode. The layer-localization of both local field potentials (LFPs) and the spread of current sink calculated by 2D-CSD analysis was characterized pharmacologically. Moreover, the induction of long-term potentiation (LTP) and changes in LTP magnitude were also evaluated. We found that under naïve conditions, the current sink was initially generated in layer VI, then spread to layer V and finally confined to layers II-III. This spatial pattern of current sink movement typically reflected changes in depolarized sites from deep layers (V-VI) to superficial layers (II-III) where intra- and extracortical inputs terminate. In the ACC slices from rats in an inflamed state (for 2 h) caused by intraplantar bee-venom injection, the spatial profile of intra-ACC synaptic organization was significantly changed, showing an enlarged current sink distribution and a leftward shift of the stimulus-response curves relative to the naïve and saline controls. The change was more distinct in the superficial layers (II-III) than in the deep site. In terms of temporal properties, the rate of LTP induction was significantly increased in layers II-III by inflammatory pain. However, the magnitude of LTP was not significantly enhanced by this treatment. Taken together, these results show that inflammatory pain results in distinct spatial and temporal plasticity of synaptic organization in the ACC, which may lead to altered synaptic transmission and modulation.
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Affiliation(s)
- Yun-Fei Lu
- Institute for Biomedical Sciences of Pain and Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi’an, 710038 China
- Key Laboratory of Brain Stress and Behavior, PLA, Xi’an, 710038 China
| | - Yan Wang
- Institute for Biomedical Sciences of Pain and Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi’an, 710038 China
- Key Laboratory of Brain Stress and Behavior, PLA, Xi’an, 710038 China
| | - Ying He
- Institute for Biomedical Sciences of Pain, Capital Medical University, Beijing, 100069 China
| | - Fu-Kang Zhang
- Institute for Biomedical Sciences of Pain, Capital Medical University, Beijing, 100069 China
| | - Ting He
- Institute for Biomedical Sciences of Pain and Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi’an, 710038 China
- Key Laboratory of Brain Stress and Behavior, PLA, Xi’an, 710038 China
| | - Rui-Rui Wang
- Institute for Biomedical Sciences of Pain and Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi’an, 710038 China
- Key Laboratory of Brain Stress and Behavior, PLA, Xi’an, 710038 China
- Institute for Biomedical Sciences of Pain, Capital Medical University, Beijing, 100069 China
| | - Xue-Feng Chen
- Institute for Biomedical Sciences of Pain and Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi’an, 710038 China
- Key Laboratory of Brain Stress and Behavior, PLA, Xi’an, 710038 China
| | - Fei Yang
- Institute for Biomedical Sciences of Pain and Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi’an, 710038 China
- Key Laboratory of Brain Stress and Behavior, PLA, Xi’an, 710038 China
| | - Ke-Rui Gong
- Institute for Biomedical Sciences of Pain, Capital Medical University, Beijing, 100069 China
| | - Jun Chen
- Institute for Biomedical Sciences of Pain and Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, Xi’an, 710038 China
- Key Laboratory of Brain Stress and Behavior, PLA, Xi’an, 710038 China
- Institute for Biomedical Sciences of Pain, Capital Medical University, Beijing, 100069 China
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Jiang L, Ji Y, Voulalas PJ, Keaser M, Xu S, Gullapalli RP, Greenspan J, Masri R. Motor cortex stimulation suppresses cortical responses to noxious hindpaw stimulation after spinal cord lesion in rats. Brain Stimul 2013; 7:182-9. [PMID: 24468093 DOI: 10.1016/j.brs.2013.12.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 12/18/2013] [Accepted: 12/23/2013] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Motor cortex stimulation (MCS) is a potentially effective treatment for chronic neuropathic pain. The neural mechanisms underlying the reduction of hyperalgesia and allodynia after MCS are not completely understood. OBJECTIVE To investigate the neural mechanisms responsible for analgesic effects after MCS. We test the hypothesis that MCS attenuates evoked blood oxygen-level dependent signals in cortical areas involved in nociceptive processing in an animal model of chronic neuropathic pain. METHODS We used adult female Sprague-Dawley rats (n = 10) that received unilateral electrolytic lesions of the right spinal cord at the level of C6 (SCL animals). In these animals, we performed magnetic resonance imaging (fMRI) experiments to study the analgesic effects of MCS. On the day of fMRI experiment, 14 days after spinal cord lesion, the animals were anesthetized and epidural bipolar platinum electrodes were placed above the left primary motor cortex. Two 10-min sessions of fMRI were performed before and after a session of MCS (50 μA, 50 Hz, 300 μs, for 30 min). During each fMRI session, the right hindpaw was electrically stimulated (noxious stimulation: 5 mA, 5 Hz, 3 ms) using a block design of 20 s stimulation off and 20 s stimulation on. A general linear model-based statistical parametric analysis was used to analyze whole brain activation maps. Region of interest (ROI) analysis and paired t-test were used to compare changes in activation before and after MCS in these ROI. RESULTS MCS suppressed evoked blood oxygen dependent signals significantly (Family-wise error corrected P < 0.05) and bilaterally in 2 areas heavily implicated in nociceptive processing. These areas consisted of the primary somatosensory cortex and the prefrontal cortex. CONCLUSIONS These findings suggest that, in animals with SCL, MCS attenuates hypersensitivity by suppressing activity in the primary somatosensory cortex and prefrontal cortex.
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Affiliation(s)
- Li Jiang
- Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Yadong Ji
- Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland School of Dentistry, Baltimore, MD 21201, USA
| | - Pamela J Voulalas
- Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Michael Keaser
- Department of Neural and Pain Sciences, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Su Xu
- Department of Sciences of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Core for Translational Research in Imaging at Maryland (C-TRIM), University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Rao P Gullapalli
- Department of Sciences of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Core for Translational Research in Imaging at Maryland (C-TRIM), University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Joel Greenspan
- Department of Neural and Pain Sciences, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Radi Masri
- Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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Yang PF, Chen YY, Chen DY, Hu JW, Chen JH, Yen CT. Comparison of fMRI BOLD response patterns by electrical stimulation of the ventroposterior complex and medial thalamus of the rat. PLoS One 2013; 8:e66821. [PMID: 23826146 PMCID: PMC3691267 DOI: 10.1371/journal.pone.0066821] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 05/10/2013] [Indexed: 12/13/2022] Open
Abstract
The objective of this study was to compare the functional connectivity of the lateral and medial thalamocortical pain pathways by investigating the blood oxygen level-dependent (BOLD) activation patterns in the forebrain elicited by direct electrical stimulation of the ventroposterior (VP) and medial (MT) thalamus. An MRI-compatible stimulation electrode was implanted in the VP or MT of α-chloralose-anesthetized rats. Electrical stimulation was applied to the VP or MT at various intensities (50 µA to 300 µA) and frequencies (1 Hz to 12 Hz). BOLD responses were analyzed in the ipsilateral forelimb region of the primary somatosensory cortex (iS1FL) after VP stimulation and in the ipsilateral cingulate cortex (iCC) after MT stimulation. When stimulating the VP, the strongest activation occurred at 3 Hz. The stimulation intensity threshold was 50 µA and the response rapidly peaked at 100 µA. When stimulating the MT, The optimal frequency for stimulation was 9 Hz or 12 Hz, the stimulation intensity threshold was 100 µA and we observed a graded increase in the BOLD response following the application of higher intensity stimuli. We also evaluated c-Fos expression following the application of a 200-µA stimulus. Ventroposterior thalamic stimulation elicited c-Fos-positivity in few cells in the iS1FL and caudate putamen (iCPu). Medial thalamic stimulation, however, produced numerous c-Fos-positive cells in the iCC and iCPu. The differential BOLD responses and c-Fos expressions elicited by VP and MT stimulation indicate differences in stimulus-response properties of the medial and lateral thalamic pain pathways.
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Affiliation(s)
- Pai-Feng Yang
- Interdisciplinary MRI/MRI Lab, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
- Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
| | - You-Yin Chen
- Department of Biomedical Engineering, National Yang-Ming University, Taipei, Taiwan
| | - Der-Yow Chen
- Department of Psychology, National Cheng Kung University, Tainan City, Taiwan
| | - James W. Hu
- Faculty of Dentistry, University of Toronto, Toronto, Canada
| | - Jyh-Horng Chen
- Interdisciplinary MRI/MRI Lab, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
- Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
- * E-mail: (JHC); (CTY)
| | - Chen-Tung Yen
- Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
- Institute of Zoology, National Taiwan University, Taipei, Taiwan
- * E-mail: (JHC); (CTY)
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Yen CT, Lu PL. Thalamus and pain. ACTA ACUST UNITED AC 2013; 51:73-80. [DOI: 10.1016/j.aat.2013.06.011] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 05/13/2013] [Indexed: 02/02/2023]
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Nardone R, Höller Y, Brigo F, Seidl M, Christova M, Bergmann J, Golaszewski S, Trinka E. Functional brain reorganization after spinal cord injury: Systematic review of animal and human studies. Brain Res 2013; 1504:58-73. [DOI: 10.1016/j.brainres.2012.12.034] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Revised: 11/26/2012] [Accepted: 12/24/2012] [Indexed: 12/18/2022]
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Shih YYI, Chen YY, Lai HY, Kao YCJ, Shyu BC, Duong TQ. Ultra high-resolution fMRI and electrophysiology of the rat primary somatosensory cortex. Neuroimage 2013; 73:113-20. [PMID: 23384528 DOI: 10.1016/j.neuroimage.2013.01.062] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 01/16/2013] [Accepted: 01/28/2013] [Indexed: 11/29/2022] Open
Abstract
High-resolution functional-magnetic-resonance-imaging (fMRI) has been used to study brain functions at increasingly finer scale, but whether fMRI can accurately reflect layer-specific neuronal activities is less well understood. The present study investigated layer-specific cerebral-blood-volume (CBV) fMRI and electrophysiological responses in the rat cortex. CBV fMRI at 40×40 μm in-plane resolution was performed on an 11.7-T scanner. Electrophysiology used a 32-channel electrode array that spanned the entire cortical depth. Graded electrical stimulation was used to study activations in different cortical layers, exploiting the notion that most of the sensory-specific neurons are in layers II-V and most of the nociceptive-specific neurons are in layers V-VI. CBV response was strongest in layer IV of all stimulus amplitudes. Current source density analysis showed strong sink currents at cortical layers IV and VI. Multi-unit activities mainly appeared at layers IV-VI and peaked at layer V. Although our measures showed scaled activation profiles during modulation of stimulus amplitude and failed to detect specific recruitment at layers V and VI during noxious electrical stimuli, there appears to be discordance between CBV fMRI and electrophysiological peak responses, suggesting neurovascular uncoupling at laminar resolution. The technique implemented in the present study offers a means to investigate intracortical neurovascular function in the normal and diseased animal models at laminar resolution.
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Affiliation(s)
- Yen-Yu Ian Shih
- Department of Neurology, University of North Carolina, Chapel Hill, NC 27599, USA.
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Chen CCV, Shih YYI, Chang C. Dopaminergic imaging of nonmotor manifestations in a rat model of Parkinson's disease by fMRI. Neurobiol Dis 2013; 49:99-106. [DOI: 10.1016/j.nbd.2012.07.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Revised: 07/04/2012] [Accepted: 07/20/2012] [Indexed: 11/29/2022] Open
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Luo W, Li P, Chen S, Luo Q. Surrounding inhibition in rat somatosensory cortex during noxious electrical stimulation of the sciatic nerve. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2012; 2005:1777-9. [PMID: 17282560 DOI: 10.1109/iembs.2005.1616791] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Surrounding inhibition is a physiologic mechanism to focus neuronal activity. Here we applied optical imaging of intrinsic signal to observing the temporal-spatial characteristic of rat primary somatosensory cortex during graded electrical stimulation of the sciatic nerve (5 Hz, duration of 2 s, 0.5 ms pulse, 1 and 10 muscle twitching threshold). We found that the magnitude and change duration (time course) of the optical signal were larger and longer with the intensity raising. The spatial extent was also wider under noxious electrical stimulus. Meanwhile, we found the inverted optical signal changes in the regions surround the activated primary somatosensory cortex. This phenomenon was similar to the inhibition surrounding focal itcal events observed by optical imaging of intrinsic signal. It suggests the surrounding inhibition under noxious electrical stimulus was probably induced by the excess discharge of excited neurons or it may provide finer discrimination during the noxious stimulus and support the view that the role of somatosensory cortex in pain localization is to finely discriminate the stimulus site.
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Affiliation(s)
- Weihua Luo
- Key Laboratory of Biomedical Photonics of Ministry of Education, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
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Su YL, Huang J, Wang N, Wang JY, Luo F. The effects of morphine on basal neuronal activities in the lateral and medial pain pathways. Neurosci Lett 2012; 525:173-8. [PMID: 22841696 DOI: 10.1016/j.neulet.2012.07.032] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 07/11/2012] [Accepted: 07/15/2012] [Indexed: 10/28/2022]
Abstract
Numerous studies indicate that morphine suppresses pain-evoked activities in both spinal and supraspinal regions. However, little is known about the effect of morphine on the basal brain activity in the absence of pain. The present study was designed to assess the effects of single-dose morphine on the spontaneous discharge of many simultaneously recorded single units, as well as their functional connections, in the lateral pain pathway, including the primary somatosensory cortex (SI) and ventral posterolateral thalamus (VPL), and medial pain pathway, including the anterior cingulate cortex (ACC) and medial dorsal thalamus (MD), in awake rats. Morphine (5mg/kg) was administered intraperitoneally before the recording. Naloxone plus morphine and normal saline injections were performed respectively as controls. The results showed that morphine administration produced significant changes in the spontaneous neuronal activity in more than one third of the total recorded neurons, with primary activation in the lateral pathway while both inhibition and activation in the medial pathway. Naloxone pretreatment completely blocked the effects induced by morphine. In addition, the correlated activities between and within both pain pathways was exclusively suppressed after morphine injection. These results suggest that morphine may play different roles in modulating neural activity in normal vs. pain states. Taken together, this is the first study investigating the morphine modulation of spontaneous neuronal activity within parallel pain pathways. It can be helpful for revealing neuronal population coding for the morphine action in the absence of pain, and shed light on the supraspinal mechanisms for preemptive analgesia.
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Affiliation(s)
- Yuan-Lin Su
- Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
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Hayes DJ, Northoff G. Common brain activations for painful and non-painful aversive stimuli. BMC Neurosci 2012; 13:60. [PMID: 22676259 PMCID: PMC3464596 DOI: 10.1186/1471-2202-13-60] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 04/18/2012] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Identification of potentially harmful stimuli is necessary for the well-being and self-preservation of all organisms. However, the neural substrates involved in the processing of aversive stimuli are not well understood. For instance, painful and non-painful aversive stimuli are largely thought to activate different neural networks. However, it is presently unclear whether there is a common aversion-related network of brain regions responsible for the basic processing of aversive stimuli. To help clarify this issue, this report used a cross-species translational approach in humans (i.e. meta-analysis) and rodents (i.e. systematic review of functional neuroanatomy). RESULTS Animal and human data combined to show a core aversion-related network, consisting of similar cortical (i.e. MCC, PCC, AI, DMPFC, RTG, SMA, VLOFC; see results section or abbreviation section for full names) and subcortical (i.e. Amyg, BNST, DS, Hab, Hipp/Parahipp, Hyp, NAc, NTS, PAG, PBN, raphe, septal nuclei, Thal, LC, midbrain) regions. In addition, a number of regions appeared to be more involved in pain-related (e.g. sensory cortex) or non-pain-related (e.g. amygdala) aversive processing. CONCLUSIONS This investigation suggests that aversive processing, at the most basic level, relies on similar neural substrates, and that differential responses may be due, in part, to the recruitment of additional structures as well as the spatio-temporal dynamic activity of the network. This network perspective may provide a clearer understanding of why components of this circuit appear dysfunctional in some psychiatric and pain-related disorders.
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Affiliation(s)
- Dave J Hayes
- Mind, Brain Imaging and Neuroethics Research Unit, Institute of Mental Health Research, University of Ottawa, 1145 Carling Avenue, Ottawa, K1Z 7K4, Canada
| | - Georg Northoff
- Mind, Brain Imaging and Neuroethics Research Unit, Institute of Mental Health Research, University of Ottawa, 1145 Carling Avenue, Ottawa, K1Z 7K4, Canada
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Thompson SJ, Bushnell MC. Rodent functional and anatomical imaging of pain. Neurosci Lett 2012; 520:131-9. [PMID: 22445887 DOI: 10.1016/j.neulet.2012.03.015] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 03/06/2012] [Accepted: 03/07/2012] [Indexed: 02/07/2023]
Abstract
Human brain imaging has provided much information about pain processing and pain modulation, but brain imaging in rodents can provide information not attainable in human studies. First, the short lifespan of rats and mice, as well as the ability to have homogenous genetics and environments, allows for longitudinal studies of the effects of chronic pain on the brain. Second, brain imaging in animals allows for the testing of central actions of novel pharmacological and nonpharmacological analgesics before they can be tested in humans. The two most commonly used brain imaging methods in rodents are magnetic resonance imaging (MRI) and positron emission tomography (PET). MRI provides better spatial and temporal resolution than PET, but PET allows for the imaging of neurotransmitters and non-neuronal cells, such as astrocytes, in addition to functional imaging. One problem with rodent brain imaging involves methods for keeping the subject still in the scanner. Both anesthetic agents and restraint techniques have potential confounds. Some PET methods allow for tracer uptake before the animal is anesthetized, but imaging a moving animal also has potential confounds. Despite the challenges associated with the various techniques, the 31 studies using either functional MRI or PET to image pain processing in rodents have yielded surprisingly consistent results, with brain regions commonly activated in human pain imaging studies (somatosensory cortex, cingulate cortex, thalamus) also being activated in the majority of these studies. Pharmacological imaging in rodents shows overlapping activation patterns with pain and opiate analgesics, similar to what is found in humans. Despite the many structural imaging studies in human chronic pain patients, only one study has been performed in rodents, but that study confirmed human findings of decreased cortical thickness associated with chronic pain. Future directions in rodent pain imaging include miniaturized PET for the freely moving animal, as well as new MRI techniques that enable ongoing chronic pain imaging.
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Affiliation(s)
- Scott J Thompson
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC H3A 2T5, Canada
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Pellicer F, López-Avila A, Coffeen U, Manuel Ortega-Legaspi J, Angel RD. Taurine in the anterior cingulate cortex diminishes neuropathic nociception: A possible interaction with the glycineA receptor. Eur J Pain 2012; 11:444-51. [PMID: 16887371 DOI: 10.1016/j.ejpain.2006.06.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Revised: 04/17/2006] [Accepted: 06/04/2006] [Indexed: 10/24/2022]
Abstract
Taurine is an inhibitory amino-acid which has been proposed as a nociceptive process neuromodulator. The glycine(A) receptor (glyR(A)) has been postulated as a receptor in which taurine exerts its function. Functional image studies have documented the role of the anterior cingulate cortex (ACC) in the affective component of pain. The aim of this study was to investigate the role of taurine as a glycinergic agonist in the ACC using a neuropathic pain model related to autotomy behaviour (AB). In order to test whether glyR(A) is responsible for taurine actions, we microinjected strychnine, a glyR(A) antagonist. We used taurine microinjected into the ACC, followed by a thermonociceptive stimulus and a sciatic denervation. Chronic nociception was measured by the autotomy score, onset and incidence. The administration of taurine 7 days after denervation modifies the temporal course of AB by inhibiting it. Our results showed a decreased autotomy score and incidence in the taurine groups, as well as a delay in the onset. Those experimental groups in which strychnine was microinjected into the ACC, either on its own or before the microinjection of taurine, showed no difference as compared to the control group. When taurine was microinjected prior to strychnine, the group behaved as if only taurine had been administered. Our results evidence a significant neuropathic nociception relief measured as an AB decrease by the microinjection of taurine into the ACC. Besides, the role of the glyR(A) is evidenced by the fact that strychnine antagonises the antinociceptive effect of taurine.
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Affiliation(s)
- Francisco Pellicer
- Laboratorio de Neurofisiología Integrativa, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría, Ramón de la Fuente, México D.F., Mexico.
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43
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Shih YYI, Chiang YC, Shyu BC, Jaw FS, Duong TQ, Chang C. Endogenous opioid-dopamine neurotransmission underlie negative CBV fMRI signals. Exp Neurol 2012; 234:382-8. [PMID: 22245158 DOI: 10.1016/j.expneurol.2011.12.042] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 12/22/2011] [Accepted: 12/25/2011] [Indexed: 10/14/2022]
Abstract
Previous studies showed noxious unilateral forepaw electrical stimulation surprisingly evoked negative blood-oxygenation-level-dependent (BOLD), cerebral blood flow (CBF), and cerebral blood volume (CBV) fMRI responses in the bilateral striatum whereas the local neuronal spike and c-Fos activities increased. These negative responses are associated with vasoconstriction and appeared to override the increased hemodynamic responses that typically accompanied with increased neural activity. The current study aimed to investigate the role of μ-opioid system in modulating vasoconstriction in the striatum associated with noxious stimulation on a 4.7-Tesla MRI scanner. Specifically, we investigated: i) how morphine (a μ-opioid receptor agonist) affects the vasoconstriction in the bilateral striatum associated with noxious electrical forepaw stimulation in rats, and ii) how naloxone (an opioid receptor antagonist) and eticlopride (a dopamine D(2)/D(3) receptor antagonist) modulates the morphine effects onwards. Injection of morphine enhanced the negative striatal CBV responses to noxious stimulation. Sequential injection of naloxone in the same animals abolished the stimulus-evoked vasoconstriction. In a separate group of animals, injection of eticlopride following morphine also reduced the vasoconstriction. Our findings suggested that noxious stimulation endogenously activated opioid and dopamine receptors in the striatum and thus leading to vasoconstriction.
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Affiliation(s)
- Yen-Yu I Shih
- Department of Neurology and Biomedical Research Imaging Center, University of North Carolina, 124 Mason Farm Rd, CB#7513, Chapel Hill, NC 27599, USA.
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Zhao F, Welsh D, Williams M, Coimbra A, Urban MO, Hargreaves R, Evelhoch J, Williams DS. fMRI of pain processing in the brain: a within-animal comparative study of BOLD vs. CBV and noxious electrical vs. noxious mechanical stimulation in rat. Neuroimage 2011; 59:1168-79. [PMID: 21856430 DOI: 10.1016/j.neuroimage.2011.08.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Revised: 07/01/2011] [Accepted: 08/02/2011] [Indexed: 11/19/2022] Open
Abstract
This study aims to identify fMRI signatures of nociceptive processing in whole brain of anesthetized rats during noxious electrical stimulation (NES) and noxious mechanical stimulation (NMS) of paw. Activation patterns for NES were mapped with blood oxygen level dependent (BOLD) and cerebral blood volume (CBV) fMRI, respectively, to investigate the spatially-dependent hemodynamic responses during nociception processing. A systematic evaluation of fMRI responses to varying frequencies of electrical stimulus was carried out to optimize the NES protocol. Both BOLD and CBV fMRI showed widespread activations, but with different spatial characteristics. While BOLD and CBV showed well-localized activations in ipsilateral dorsal column nucleus, contralateral primary somatosensory cortex (S1), and bilateral caudate putamen (CPu), CBV fMRI showed additional bilateral activations in the regions of pons, midbrain and thalamus compared to BOLD fMRI. CBV fMRI that offers higher sensitivity compared to BOLD was then used to compare the nociception processing during NES and NMS in the same animal. The activations in most regions were similar. In the medulla, however, NES induced a robust activation in the ipsilateral dorsal column nucleus while NMS showed no activation. This study demonstrates that (1) the hemodynamic response to nociception is spatial-dependent; (2) the widespread activations during nociception in CBV fMRI are similar to what have been observed in (14)C-2-deoxyglucose (2DG) autoradiography and PET; (3) the bilateral activations in the brain originate from the divergence of neural responses at supraspinal level; and (4) the similarity of activation patterns suggests that nociceptive processing in rats is similar during NES and NMS.
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Affiliation(s)
- Fuqiang Zhao
- Imaging Department, Merck Research Laboratories, West Point, PA 19486, USA.
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Hoot MR, Sim-Selley LJ, Selley DE, Scoggins KL, Dewey WL. Chronic neuropathic pain in mice reduces μ-opioid receptor-mediated G-protein activity in the thalamus. Brain Res 2011; 1406:1-7. [PMID: 21762883 DOI: 10.1016/j.brainres.2011.06.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 06/06/2011] [Accepted: 06/09/2011] [Indexed: 01/01/2023]
Abstract
Neuropathic pain is a debilitating condition that is often difficult to treat using conventional pharmacological interventions and the exact mechanisms involved in the establishment and maintenance of this type of chronic pain have yet to be fully elucidated. The present studies examined the effect of chronic nerve injury on μ-opioid receptors and receptor-mediated G-protein activity within the supraspinal brain regions involved in pain processing of mice. Chronic constriction injury (CCI) reduced paw withdrawal latency, which was maximal at 10 days post-injury. [d-Ala2,(N-Me)Phe4,Gly5-OH] enkephalin (DAMGO)-stimulated [(35)S]GTPγS binding was then conducted at this time point in membranes prepared from the rostral ACC (rACC), thalamus and periaqueductal grey (PAG) of CCI and sham-operated mice. Results showed reduced DAMGO-stimulated [(35)S]GTPγS binding in the thalamus and PAG of CCI mice, with no change in the rACC. In thalamus, this reduction was due to decreased maximal stimulation by DAMGO, with no difference in EC(50) values. In PAG, however, DAMGO E(max) values did not significantly differ between groups, possibly due to the small magnitude of the main effect. [(3)H]Naloxone binding in membranes of the thalamus showed no significant differences in B(max) values between CCI and sham-operated mice, indicating that the difference in G-protein activation did not result from differences in μ-opioid receptor levels. These results suggest that CCI induced a region-specific adaptation of μ-opioid receptor-mediated G-protein activity, with apparent desensitization of the μ-opioid receptor in the thalamus and PAG and could have implications for treatment of neuropathic pain.
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Affiliation(s)
- Michelle R Hoot
- Virginia Commonwealth University, Department of Pharmacology and Toxicology, Richmond, USA
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Abstract
Sensory and motor representations embedded in topographic cortical maps are use-dependent, dynamically maintained, and self-organizing functional mosaics that constitute idiosyncratic entities involved in perceptual and motor learning abilities. Studies of cortical map plasticity have substantiated the view that local reorganization of sensory and motor areas has great significance in recovery of function following brain damage or spinal cord injury. In addition, the transfer of function to distributed cortical areas and subcortical structures represents an adaptive strategy for functional compensation. There is a growing consensus that subject-environment interactions, by continuously refining the canvas of synaptic connectivity and reshaping the anatomical and functional architecture of neural circuits, promote adaptive behavior throughout life. Taking advantage of use-dependent neural plasticity, early initiated rehabilitative procedures improve the potential for recovery.
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Affiliation(s)
- Christian Xerri
- Integrative and Adaptive Neurosciences, University of Provence/CNRS, Marseille, France
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Chen YY, Shih YYI, Lo YC, Lu PL, Tsang S, Jaw FS, Liu RS. MicroPET imaging of noxious thermal stimuli in the conscious rat brain. Somatosens Mot Res 2011; 27:69-81. [PMID: 20735340 DOI: 10.3109/08990220.2010.508222] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Small animal positron emission tomography (microPET) has been utilized in the investigation of nociception. However, a possible drawback from previous studies is the reduced activation pattern due to the application of anesthesia. The purpose of the present study was to demonstrate a potential means of avoiding anesthesia during stimulation, as well as minimizing the confounding anesthetic effect. Sodium pentobarbital and ketamine were first evaluated to determine their effect on microPET images in the current study. [(18)F]-Fluorodeoxyglucose ((18)F-FDG) was an appropriate radiotracer to reveal activated regions in rat brains. Pentobarbital anesthesia significantly reduced (18)F-FDG uptake in neural tissues, blurrier to lower contrast; therefore, ketamine was used to anesthetize animals during microPET. After the rats were anesthetized and secured in a laboratory-made stereotaxic frame, a simple, noninvasive stereotaxic technique was used to position their heads in the microPET scanner and to roughly conform the images in the stereotaxic atlas. For functional imaging, conscious rats were restrained in cages with minimal ambient noise; short repetitive thermal stimuli were applied to each rat's tail subsequently. The rats were adequately anesthetized with ketamine following 30 min of scanning without stimulation. An activation index (AI) was calculated from microPET data to quantify the local metabolic activity changes according to the normalized (18)F-FDG dosage. The average AI indicated a side-to-side difference for all innocuous stimulations in the thalamus. However, such side-to-side difference was only observed for noxious heat and cold stimulations in primary somatosensory cortex (SI), secondary somatosensory cortex (SII), and agranular insular cortex (AIC). The present study demonstrated the feasibility of the microPET technique to image metabolic functions of the conscious rat brain, offering better rationale and protocol designs for future pain studies.
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Affiliation(s)
- You-Yin Chen
- Department of Electrical Engineering, National Chiao Tung University, Hsinchu, Taiwan, ROC.
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Yang PF, Chen DY, Hu JW, Chen JH, Yen CT. Functional tracing of medial nociceptive pathways using activity-dependent manganese-enhanced MRI. Pain 2011; 152:194-203. [DOI: 10.1016/j.pain.2010.10.027] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2009] [Revised: 10/09/2010] [Accepted: 10/20/2010] [Indexed: 11/30/2022]
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CNS animal fMRI in pain and analgesia. Neurosci Biobehav Rev 2010; 35:1125-43. [PMID: 21126534 DOI: 10.1016/j.neubiorev.2010.11.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Revised: 11/22/2010] [Accepted: 11/23/2010] [Indexed: 11/22/2022]
Abstract
Animal imaging of brain systems offers exciting opportunities to better understand the neurobiology of pain and analgesia. Overall functional studies have lagged behind human studies as a result of technical issues including the use of anesthesia. Now that many of these issues have been overcome including the possibility of imaging awake animals, there are new opportunities to study whole brain systems neurobiology of acute and chronic pain as well as analgesic effects on brain systems de novo (using pharmacological MRI) or testing in animal models of pain. Understanding brain networks in these areas may provide new insights into translational science, and use neural networks as a "language of translation" between preclinical to clinical models. In this review we evaluate the role of functional and anatomical imaging in furthering our understanding in pain and analgesia.
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Bosshard SC, Baltes C, Wyss MT, Mueggler T, Weber B, Rudin M. Assessment of brain responses to innocuous and noxious electrical forepaw stimulation in mice using BOLD fMRI. Pain 2010; 151:655-663. [PMID: 20851520 DOI: 10.1016/j.pain.2010.08.025] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2009] [Revised: 08/04/2010] [Accepted: 08/17/2010] [Indexed: 10/19/2022]
Abstract
Functional magnetic resonance imaging (fMRI) using the blood oxygen level-dependent (BOLD) contrast was used to study sensory processing in the brain of isoflurane-anesthetized mice. The use of a cryogenic surface coil in a small animal 9.4T system provided the sensitivity required for detection and quantitative analysis of hemodynamic changes caused by neural activity in the mouse brain in response to electrical forepaw stimulation at different amplitudes. A gradient echo-echo planar imaging (GE-EPI) sequence was used to acquire five coronal brain slices of 0.5mm thickness. BOLD signal changes were observed in primary and secondary somatosensory cortices, the thalamus and the insular cortex, important regions involved in sensory and nociceptive processing. Activation was observed consistently bilateral despite unilateral stimulation of the forepaw. The temporal BOLD profile was segregated into two signal components with different temporal characteristics. The maximum BOLD amplitude of both signal components correlated strongly with the stimulation amplitude. Analysis of the dynamic behavior of the somatosensory 'fast' BOLD component revealed a decreasing signal decay rate constant k(off) with increasing maximum BOLD amplitude (and stimulation amplitude). This study demonstrates the feasibility of a robust BOLD fMRI protocol to study nociceptive processing in isoflurane-anesthetized mice. The reliability of the method allows for detailed analysis of the temporal BOLD profile and for investigation of somatosensory and noxious signal processing in the brain, which is attractive for characterizing genetically engineered mouse models.
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Affiliation(s)
- Simone C Bosshard
- Institute for Biomedical Engineering, University and ETH Zurich, Switzerland Institute of Pharmacology and Toxicology, University of Zurich, Switzerland PET Center, Department of Nuclear Medicine, University Hospital Zürich, Switzerland
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