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Patil N, Korenfeld O, Scalf RN, Lavoie N, Huntemer-Silveira A, Han G, Swenson R, Parr AM. Electrical stimulation affects the differentiation of transplanted regionally specific human spinal neural progenitor cells (sNPCs) after chronic spinal cord injury. Stem Cell Res Ther 2023; 14:378. [PMID: 38124191 PMCID: PMC10734202 DOI: 10.1186/s13287-023-03597-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 12/04/2023] [Indexed: 12/23/2023] Open
Abstract
BACKGROUND There are currently no effective clinical therapies to ameliorate the loss of function that occurs after spinal cord injury. Electrical stimulation of the rat spinal cord through the rat tail has previously been described by our laboratory. We propose combinatorial treatment with human induced pluripotent stem cell-derived spinal neural progenitor cells (sNPCs) along with tail nerve electrical stimulation (TANES). The purpose of this study was to examine the influence of TANES on the differentiation of sNPCs with the hypothesis that the addition of TANES would affect incorporation of sNPCs into the injured spinal cord, which is our ultimate goal. METHODS Chronically injured athymic nude rats were allocated to one of three treatment groups: injury only, sNPC only, or sNPC + TANES. Rats were sacrificed at 16 weeks post-transplantation, and tissue was processed and analyzed utilizing standard histological and tissue clearing techniques. Functional testing was performed. All quantitative data were presented as mean ± standard error of the mean. Statistics were conducted using GraphPad Prism. RESULTS We found that sNPCs were multi-potent and retained the ability to differentiate into mainly neurons or oligodendrocytes after this transplantation paradigm. The addition of TANES resulted in more transplanted cells differentiating into oligodendrocytes compared with no TANES treatment, and more myelin was found. TANES not only promoted significantly higher numbers of sNPCs migrating away from the site of injection but also influenced long-distance axonal/dendritic projections especially in the rostral direction. Further, we observed localization of synaptophysin on SC121-positive cells, suggesting integration with host or surrounding neurons, and this finding was enhanced when TANES was applied. Also, rats that were transplanted with sNPCs in combination with TANES resulted in an increase in serotonergic fibers in the lumbar region. This suggests that TANES contributes to integration of sNPCs, as well as activity-dependent oligodendrocyte and myelin remodeling of the chronically injured spinal cord. CONCLUSIONS Together, the data suggest that the added electrical stimulation promoted cellular integration and influenced the fate of human induced pluripotent stem cell-derived sNPCs transplanted into the injured spinal cord.
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Affiliation(s)
- Nandadevi Patil
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, 2-214 MTRF, 2001 6th St. SE, Minneapolis, MN, 55455, USA
| | - Olivia Korenfeld
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, 2-214 MTRF, 2001 6th St. SE, Minneapolis, MN, 55455, USA
| | - Rachel N Scalf
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, 2-214 MTRF, 2001 6th St. SE, Minneapolis, MN, 55455, USA
| | - Nicolas Lavoie
- Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA, 02139, USA
| | - Anne Huntemer-Silveira
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, 2-214 MTRF, 2001 6th St. SE, Minneapolis, MN, 55455, USA
| | - Guebum Han
- Department of Mechanical Engineering, College of Science and Engineering, University of Minnesota, 1100 Mechanical Engineering Building, 111 Church St. SE, Minneapolis, MN, 55455, USA
| | - Riley Swenson
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, 2-214 MTRF, 2001 6th St. SE, Minneapolis, MN, 55455, USA
| | - Ann M Parr
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, MMC 96, 420 Delaware St. SE, Minneapolis, MN, 55455, USA.
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Lyubashina OA, Sivachenko IB, Sushkevich BM, Busygina II. Opposing effects of 5-HT1A receptor agonist buspirone on supraspinal abdominal pain transmission in normal and visceral hypersensitive rats. J Neurosci Res 2023; 101:1555-1571. [PMID: 37331003 DOI: 10.1002/jnr.25222] [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: 02/14/2023] [Revised: 05/11/2023] [Accepted: 05/28/2023] [Indexed: 06/20/2023]
Abstract
The serotonergic 5-HT1A receptors are implicated in the central mechanisms of visceral pain, but their role in these processes is controversial. Considering existing evidences for organic inflammation-triggered neuroplastic changes in the brain serotonergic circuitry, the ambiguous contribution of 5-HT1A receptors to supraspinal control of visceral pain in normal and post-inflammatory conditions can be assumed. In this study performed on male Wistar rats, we used microelectrode recording of the caudal ventrolateral medulla (CVLM) neuron responses to colorectal distension (CRD) and electromyography recording of CRD-evoked visceromotor reactions (VMRs) to evaluate post-colitis changes in the effects of 5-HT1A agonist buspirone on supraspinal visceral nociceptive transmission. In rats recovered from trinitrobenzene sulfonic acid colitis, the CRD-induced CVLM neuronal excitation and VMRs were increased compared with those in healthy animals, revealing post-inflammatory intestinal hypersensitivity. Intravenous buspirone (2 and 4 mg/kg) under urethane anesthesia dose-dependently suppressed CVLM excitatory neuron responses to noxious CRD in healthy rats, but caused dose-independent increase in the already enhanced nociceptive activation of CVLM neurons in post-colitis animals, losing also its normally occurring faciliatory effect on CRD-evoked inhibitory medullary neurotransmission and suppressive action on hemodynamic reactions to CRD. In line with this, subcutaneous injection of buspirone (2 mg/kg) in conscious rats, which attenuated CRD-induced VMRs in controls, further increased VMRs in hypersensitive animals. The data obtained indicate a shift from anti- to pronociceptive contribution of 5-HT1A-dependent mechanisms to supraspinal transmission of visceral nociception in intestinal hypersensitivity conditions, arguing for the disutility of buspirone and possibly other 5-HT1A agonists for relieving post-inflammatory abdominal pain.
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Affiliation(s)
- Olga A Lyubashina
- Laboratory of Cortico-Visceral Physiology, Pavlov Institute of Physiology of the Russian Academy of Sciences, Saint Petersburg, Russia
| | - Ivan B Sivachenko
- Laboratory of Cortico-Visceral Physiology, Pavlov Institute of Physiology of the Russian Academy of Sciences, Saint Petersburg, Russia
| | - Boris M Sushkevich
- Laboratory of Cortico-Visceral Physiology, Pavlov Institute of Physiology of the Russian Academy of Sciences, Saint Petersburg, Russia
| | - Irina I Busygina
- Laboratory of Cortico-Visceral Physiology, Pavlov Institute of Physiology of the Russian Academy of Sciences, Saint Petersburg, Russia
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REEDICH EJ, GENRY L, STEELE P, AVILA EMENA, DOWALIBY L, DROBYSHEVSKY A, MANUEL M, QUINLAN KA. Spinal motoneurons respond aberrantly to serotonin in a rabbit model of cerebral palsy. J Physiol 2023; 601:4271-4289. [PMID: 37584461 PMCID: PMC10543617 DOI: 10.1113/jp284803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 07/24/2023] [Indexed: 08/17/2023] Open
Abstract
Cerebral palsy (CP) is caused by a variety of factors that damage the developing central nervous system. Impaired motor control, including muscle stiffness and spasticity, is the hallmark of spastic CP. Rabbits that experience hypoxic-ischaemic (HI) injury in utero (at 70%-83% gestation) are born with muscle stiffness, hyperreflexia and, as recently discovered, increased 5-HT in the spinal cord. To determine whether serotonergic modulation of spinal motoneurons (MNs) contributes to motor deficits, we performed ex vivo whole cell patch clamp in neonatal rabbit spinal cord slices at postnatal day (P) 0-5. HI MNs responded to the application of α-methyl 5-HT (a 5-HT1 /5-HT2 receptor agonist) and citalopram (a selective 5-HT reuptake inhibitor) with increased amplitude and hyperpolarization of persistent inward currents and hyperpolarized threshold voltage for action potentials, whereas control MNs did not exhibit any of these responses. Although 5-HT similarly modulated MN properties of HI motor-unaffected and motor-affected kits, it affected sag/hyperpolarization-activated cation current (Ih ) and spike frequency adaptation only in HI motor-affected MNs. To further explore the differential sensitivity of MNs to 5-HT, we performed immunostaining for inhibitory 5-HT1A receptors in lumbar spinal MNs at P5. Fewer HI MNs expressed the 5-HT1A receptor compared to age-matched control MNs. This suggests that HI MNs may lack a normal mechanism of central fatigue, mediated by 5-HT1A receptors. Altered expression of other 5-HT receptors (including 5-HT2 ) likely also contributes to the robust increase in HI MN excitability. In summary, by directly exciting MNs, the increased concentration of spinal 5-HT in HI-affected rabbits can cause MN hyperexcitability, muscle stiffness and spasticity characteristic of CP. Therapeutic strategies that target serotonergic neuromodulation may be beneficial to individuals with CP. KEY POINTS: We used whole cell patch clamp electrophysiology to test the responsivity of spinal motoneurons (MNs) from neonatal control and hypoxia-ischaemia (HI) rabbits to 5-HT, which is elevated in the spinal cord after prenatal HI injury. HI rabbit MNs showed a more robust excitatory response to 5-HT than control rabbit MNs, including hyperpolarization of the persistent inward current and threshold voltage for action potentials. Although most MN properties of HI motor-unaffected and motor-affected kits responded similarly to 5-HT, 5-HT caused larger sag/hyperpolarization-activated cation current (Ih ) and altered repetitive firing patterns only in HI motor-affected MNs. Immunostaining revealed that fewer lumbar MNs expressed inhibitory 5-HT1A receptors in HI rabbits compared to controls, which could account for the more robust excitatory response of HI MNs to 5-HT. These results suggest that elevated 5-HT after prenatal HI injury could trigger a cascade of events that lead to muscle stiffness and altered motor unit development.
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Affiliation(s)
- E. J. REEDICH
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
| | - L.T. GENRY
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
- Interdisciplinary Neuroscience Program, University of Rhode Island, Kingston, RI, USA
| | - P.R. STEELE
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
- Interdisciplinary Neuroscience Program, University of Rhode Island, Kingston, RI, USA
| | - E. MENA AVILA
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
| | - L. DOWALIBY
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
| | | | - M. MANUEL
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
- Interdisciplinary Neuroscience Program, University of Rhode Island, Kingston, RI, USA
| | - K. A. QUINLAN
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
- Interdisciplinary Neuroscience Program, University of Rhode Island, Kingston, RI, USA
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Munawar N, Bitar MS, Masocha W. Activation of 5-HT1A Receptors Normalizes the Overexpression of Presynaptic 5-HT1A Receptors and Alleviates Diabetic Neuropathic Pain. Int J Mol Sci 2023; 24:14334. [PMID: 37762636 PMCID: PMC10532078 DOI: 10.3390/ijms241814334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 08/11/2023] [Accepted: 08/23/2023] [Indexed: 09/29/2023] Open
Abstract
Neuropathic pain is a well-documented phenomenon in experimental and clinical diabetes; however, current treatment is unsatisfactory. Serotoninergic-containing neurons are key components of the descending autoinhibitory pathway, and a decrease in their activity may contribute at least in part to diabetic neuropathic pain (DNP). A streptozotocin (STZ)-treated rat was used as a model for type 1 diabetes mellitus (T1DM). Pain transmission was evaluated using well-established nociceptive-based techniques, including the Hargreaves apparatus, cold plate and dynamic plantar aesthesiometer. Using qRT-PCR, Western blotting, immunohistochemistry, and HPLC-based techniques, we also measured in the central nervous system and peripheral nervous system of diabetic animals the expression and localization of 5-HT1A receptors (5-HT1AR), levels of key enzymes involved in the synthesis and degradation of tryptophan and 5-HT, including tryptophan hydroxylase-2 (Tph-2), tryptophan 2,3-dioxygenase (Tdo), indoleamine 2,3-dioxygenase 1 (Ido1) and Ido2. Moreover, spinal concentrations of 5-HT, 5-hydroxyindoleacetic acid (5-HIAA, a metabolite of 5-HT) and quinolinic acid (QA, a metabolite of tryptophan) were also quantified. Diabetic rats developed thermal hyperalgesia and cold/mechanical allodynia, and these behavioral abnormalities appear to be associated with the upregulation in the levels of expression of critical molecules related to the serotoninergic nervous system, including presynaptic 5-HT1AR and the enzymes Tph-2, Tdo, Ido1 and Ido2. Interestingly, the level of postsynaptic 5-HT1AR remains unaltered in STZ-induced T1DM. Chronic treatment of diabetic animals with 8-hydroxy-2-(dipropylamino)tetralin (8-OH-DPAT), a selective 5-HT1AR agonist, downregulated the upregulation of neuronal presynaptic 5-HT1AR, increased spinal release of 5-HT (↑ 5-HIAA/5-HT) and reduced the concentration of QA, decreased mRNA expression of Tdo, Ido1 and Ido2, arrested neuronal degeneration and ameliorated pain-related behavior as exemplified by thermal hyperalgesia and cold/mechanical allodynia. These data show that 8-OH-DPAT alleviates DNP and other components of the serotoninergic system, including the ratio of 5-HIAA/5-HT and 5-HT1AR, and could be a useful therapeutic agent for managing DNP.
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Affiliation(s)
- Neha Munawar
- Department of Pharmacology and Toxicology, College of Medicine, Kuwait University, Al-Jabriya 046302, Kuwait;
| | - Milad S. Bitar
- Department of Pharmacology and Toxicology, College of Medicine, Kuwait University, Al-Jabriya 046302, Kuwait;
| | - Willias Masocha
- Department of Pharmacology and Therapeutics, College of Pharmacy, Kuwait University, Al-Jabriya 046302, Kuwait;
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Ortiz YT, Bilbrey JA, Felix JS, Kienegger EA, Mottinelli M, Mukhopadhyay S, McCurdy CR, McMahon LR, Wilkerson JL. Cannabidiol and mitragynine exhibit differential interactive effects in the attenuation of paclitaxel-induced mechanical allodynia, acute antinociception, and schedule-controlled responding in mice. Pharmacol Rep 2023; 75:937-950. [PMID: 37243887 DOI: 10.1007/s43440-023-00498-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 05/12/2023] [Accepted: 05/15/2023] [Indexed: 05/29/2023]
Abstract
BACKGROUND For many chemotherapy patients peripheral neuropathy is a debilitating side effect. Mitragyna speciosa (kratom) contains the alkaloid mitragynine (MG), which produces analgesia in multiple preclinical pain models. In humans, anecdotal reports suggest cannabidiol (CBD) may enhance kratom-related analgesia. We examined the interactive activity of MG and CBD in a mouse chemotherapy-induced peripheral neuropathy (CIPN) model. We also examined MG + CBD in acute antinociception and schedule-controlled responding assays, as well as examined underlying receptor mechanisms. METHODS Male and female C57BL/6J mice received a cycle of intraperitoneal (ip) paclitaxel injections (cumulative dose 32 mg/kg). The von Frey assay was utilized to assess CIPN allodynia. In paclitaxel-naïve mice, schedule-controlled responding for food was conducted under a fixed ratio (FR)-10, and hot plate antinociception was examined. RESULTS MG dose-relatedly attenuated CIPN allodynia (ED50 102.96 mg/kg, ip), reduced schedule-controlled responding (ED50 46.04 mg/kg, ip), and produced antinociception (ED50 68.83 mg/kg, ip). CBD attenuated allodynia (ED50 85.14 mg/kg, ip) but did not decrease schedule-controlled responding or produce antinociception. Isobolographic analysis revealed 1:1, 3:1 MG + CBD mixture ratios additively attenuated CIPN allodynia. All combinations decreased schedule-controlled responding and produced antinociception. WAY-100635 (serotonin 5-HT1A receptor antagonist) pretreatment (0.01 mg/kg, ip) antagonized CBD anti-allodynia. Naltrexone (pan opioid receptor antagonist) pretreatment (0.032 mg/kg, ip) antagonized MG anti-allodynia and acute antinociception but produced no change in MG-induced decreased schedule-controlled behavior. Yohimbine (α2 receptor antagonist) pretreatment (3.2 mg/kg, ip) antagonized MG anti-allodynia and produced no change in MG-induced acute antinociception or decreased schedule-controlled behavior. CONCLUSIONS Although more optimization is needed, these data suggest CBD combined with MG may be useful as a novel CIPN therapeutic.
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Affiliation(s)
- Yuma T Ortiz
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, USA
- Department of Pharmaceutical Sciences, Jerry H. Hodge School of Pharmacy, Texas Tech University Health Sciences Center, 1406 S. Coulter., Amarillo, TX, 79106, USA
| | - Joshua A Bilbrey
- College of Pharmacy, University of Florida, Gainesville, FL, USA
| | - Jasmine S Felix
- College of Pharmacy, University of Florida, Gainesville, FL, USA
| | - Erik A Kienegger
- College of Pharmacy, University of Florida, Gainesville, FL, USA
| | - Marco Mottinelli
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, FL, USA
- Department of Chemistry and Chemical Biology, College of Science, Northeastern University, Boston, MA, USA
| | - Sushobhan Mukhopadhyay
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, FL, USA
| | - Christopher R McCurdy
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, FL, USA
| | - Lance R McMahon
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, USA
- Department of Pharmaceutical Sciences, Jerry H. Hodge School of Pharmacy, Texas Tech University Health Sciences Center, 1406 S. Coulter., Amarillo, TX, 79106, USA
| | - Jenny L Wilkerson
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, USA.
- Department of Pharmaceutical Sciences, Jerry H. Hodge School of Pharmacy, Texas Tech University Health Sciences Center, 1406 S. Coulter., Amarillo, TX, 79106, USA.
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REEDICH EJ, GENRY L, STEELE P, AVILA EMENA, DOWALIBY L, DROBYSHEVSKY A, MANUEL M, QUINLAN KA. Spinal motoneurons respond aberrantly to serotonin in a rabbit model of cerebral palsy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.05.535691. [PMID: 37066318 PMCID: PMC10104065 DOI: 10.1101/2023.04.05.535691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Cerebral palsy (CP) is caused by a variety of factors that damage the developing central nervous system. Impaired motor control, including muscle stiffness and spasticity, is the hallmark of spastic CP. Rabbits that experience hypoxic-ischemic (HI) injury in utero (at 70-80% gestation) are born with muscle stiffness, hyperreflexia, and, as recently discovered, increased serotonin (5-HT) in the spinal cord. To determine whether serotonergic modulation of spinal motoneurons (MNs) contributes to motor deficits, we performed ex vivo whole cell patch clamp in neonatal rabbit spinal cord slices at postnatal day (P) 0-5. HI MNs responded to application of α-methyl 5-HT (a 5-HT 1 /5-HT 2 receptor agonist) and citalopram (a selective 5-HT reuptake inhibitor) with hyperpolarization of persistent inward currents and threshold voltage for action potentials, reduced maximum firing rate, and an altered pattern of spike frequency adaptation while control MNs did not exhibit any of these responses. To further explore the differential sensitivity of MNs to 5-HT, we performed immunohistochemistry for inhibitory 5-HT 1A receptors in lumbar spinal MNs at P5. Fewer HI MNs expressed the 5-HT 1A receptor compared to age-matched controls. This suggests many HI MNs lack a normal mechanism of central fatigue mediated by 5-HT 1A receptors. Other 5-HT receptors (including 5-HT 2 ) are likely responsible for the robust increase in HI MN excitability. In summary, by directly exciting MNs, the increased concentration of spinal 5-HT in HI rabbits can cause MN hyperexcitability, muscle stiffness, and spasticity characteristic of CP. Therapeutic strategies that target serotonergic neuromodulation may be beneficial to individuals with CP. Key points After prenatal hypoxia-ischemia (HI), neonatal rabbits that show hypertonia are known to have higher levels of spinal serotoninWe tested responsivity of spinal motoneurons (MNs) in neonatal control and HI rabbits to serotonin using whole cell patch clampMNs from HI rabbits showed a more robust excitatory response to serotonin than control MNs, including hyperpolarization of the persistent inward current and threshold for action potentials, larger post-inhibitory rebound, and less spike frequency adaptation Based on immunohistochemistry of lumbar MNs, fewer HI MNs express inhibitory 5HT 1A receptors than control MNs, which could account for the more robust excitatory response of HI MNs. These results suggest that after HI injury, the increased serotonin could trigger a cascade of events leading to muscle stiffness and altered motor unit development.
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Affiliation(s)
- E. J. REEDICH
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
| | - L.T. GENRY
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
- Interdisciplinary Neuroscience Program, University of Rhode Island, Kingston, RI, USA
| | - P.R. STEELE
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
- Interdisciplinary Neuroscience Program, University of Rhode Island, Kingston, RI, USA
| | - E. MENA AVILA
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
| | - L. DOWALIBY
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
| | | | - M. MANUEL
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
- Interdisciplinary Neuroscience Program, University of Rhode Island, Kingston, RI, USA
| | - K. A. QUINLAN
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
- Interdisciplinary Neuroscience Program, University of Rhode Island, Kingston, RI, USA
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Li CJ, Zhang LG, Liu LB, An MQ, Dong LG, Gu HY, Dai YP, Wang F, Mao CJ, Liu CF. Inhibition of Spinal 5-HT3 Receptor and Spinal Dorsal Horn Neuronal Excitability Alleviates Hyperalgesia in a Rat Model of Parkinson's Disease. Mol Neurobiol 2022; 59:7253-7264. [PMID: 36168076 DOI: 10.1007/s12035-022-03034-8] [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: 02/21/2022] [Accepted: 09/14/2022] [Indexed: 10/14/2022]
Abstract
Pain in Parkinson's disease (PD) is increasingly recognized as a major factor associated with poor life quality of PD patients. However, classic therapeutic drugs supplying dopamine have limited therapeutic effects on PD-related pain. This suggests that there is a mechanism outside the dopamine system that causes pain in PD. Our previous study demonstrated that 6-OHDA induced PD model manifested hyperalgesia to thermal and mechanical stimuli and decreased serotonin (5-hydroxytryptamine; 5-HT) in the spinal dorsal horn (SDH). Several 5-HT receptor subtypes have been confirmed to be associated with nociception in the spinal cord, such as 5-HT1A receptor, 5-HT1B receptor, 5-HT2 receptor, 5-HT3 receptor, and 5-HT7 receptor. Most research has shown that 5-HT1A receptor and 5-HT3 receptor play a key role in pain transmission in the spinal cord. We hypothesized that hyperalgesia of 6-OHDA rats may be related to increased excitability of SDH neurons, and functional change of 5-HT3 receptor may reverse the hyperalgesia of 6-OHDA lesioned rats and decrease cell excitability of SDH neurons. To test this hypothesis, we used whole-cell patch-clamp and pharmacological methods to evaluate the effect of 5-HT3 receptor and 5-HT1A receptor on the hyperalgesia of 6-OHDA rats. The results suggested that increased excitability in SDH neurons could be reversed by 5-HT3 receptor antagonist ondansetron (20 μmol/L) and palosetron (10 μmol/L), but not 5-HT3 receptor agonist m-CPBG (30 μmol/L) and SR 57,727 (10 μmol/L), 5-HT1A receptor agonist 8-OH DPAT (10 μmol/L) and eptapirone (10 μmol/L) and 5-HT1A receptor antagonist WAY-100635 (10 μmol/L) and p-MPPI (10 μmol/L). Intrathecal injection of ondansetron (0.1 mg/kg) but not m-CPBG (0.1 mg/kg), 8-OH DPAT (0.1 mg/kg), and WAY-100635 (0.1 mg/kg) significantly attenuated the mechanical hyperalgesia and thermal hyperalgesia in 6-OHDA lesioned rats. In conclusion, the present study suggests that inhibition of spinal 5-HT3 receptor and SDH neuronal excitability alleviates hyperalgesia in PD rats. Our study provides a novel mechanism or therapeutic strategy for pain in patients with PD.
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Affiliation(s)
- Cheng-Jie Li
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, 1055 Sanxiang Road, Suzhou, 215004, China.,Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Li-Ge Zhang
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, 1055 Sanxiang Road, Suzhou, 215004, China.,Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Lu-Bing Liu
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Meng-Qi An
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Li-Guo Dong
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, 1055 Sanxiang Road, Suzhou, 215004, China.,Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Han-Ying Gu
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, 1055 Sanxiang Road, Suzhou, 215004, China
| | - Yong-Ping Dai
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, 1055 Sanxiang Road, Suzhou, 215004, China
| | - Fen Wang
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, 1055 Sanxiang Road, Suzhou, 215004, China. .,Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China.
| | - Cheng-Jie Mao
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, 1055 Sanxiang Road, Suzhou, 215004, China.
| | - Chun-Feng Liu
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, 1055 Sanxiang Road, Suzhou, 215004, China.,Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China.,Department of Neurology, The Second Affiliated Hospital of Xinjiang Medical University, Urumqi, China
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8
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Ortiz YT, McMahon LR, Wilkerson JL. Medicinal Cannabis and Central Nervous System Disorders. Front Pharmacol 2022; 13:881810. [PMID: 35529444 PMCID: PMC9070567 DOI: 10.3389/fphar.2022.881810] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 04/05/2022] [Indexed: 01/02/2023] Open
Abstract
Cannabinoids, including those found in cannabis, have shown promise as potential therapeutics for numerous health issues, including pathological pain and diseases that produce an impact on neurological processing and function. Thus, cannabis use for medicinal purposes has become accepted by a growing majority. However, clinical trials yielding satisfactory endpoints and unequivocal proof that medicinal cannabis should be considered a frontline therapeutic for most examined central nervous system indications remains largely elusive. Although cannabis contains over 100 + compounds, most preclinical and clinical research with well-controlled dosing and delivery methods utilize the various formulations of Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), the two most abundant compounds in cannabis. These controlled dosing and delivery methods are in stark contrast to most clinical studies using whole plant cannabis products, as few clinical studies using whole plant cannabis profile the exact composition, including percentages of all compounds present within the studied product. This review will examine both preclinical and clinical evidence that supports or refutes the therapeutic utility of medicinal cannabis for the treatment of pathological pain, neurodegeneration, substance use disorders, as well as anxiety-related disorders. We will predominately focus on purified THC and CBD, as well as other compounds isolated from cannabis for the aforementioned reasons but will also include discussion over those studies where whole plant cannabis has been used. In this review we also consider the current challenges associated with the advancement of medicinal cannabis and its derived potential therapeutics into clinical applications.
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Affiliation(s)
- Yuma T. Ortiz
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, United States
| | - Lance R. McMahon
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, Amarillo, TX, United States
| | - Jenny L. Wilkerson
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, Amarillo, TX, United States
- *Correspondence: Jenny L. Wilkerson,
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9
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Abstract
Cannabinoids, including those found in cannabis, have shown promise as potential therapeutics for numerous health issues, including pathological pain and diseases that produce an impact on neurological processing and function. Thus, cannabis use for medicinal purposes has become accepted by a growing majority. However, clinical trials yielding satisfactory endpoints and unequivocal proof that medicinal cannabis should be considered a frontline therapeutic for most examined central nervous system indications remains largely elusive. Although cannabis contains over 100 + compounds, most preclinical and clinical research with well-controlled dosing and delivery methods utilize the various formulations of Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), the two most abundant compounds in cannabis. These controlled dosing and delivery methods are in stark contrast to most clinical studies using whole plant cannabis products, as few clinical studies using whole plant cannabis profile the exact composition, including percentages of all compounds present within the studied product. This review will examine both preclinical and clinical evidence that supports or refutes the therapeutic utility of medicinal cannabis for the treatment of pathological pain, neurodegeneration, substance use disorders, as well as anxiety-related disorders. We will predominately focus on purified THC and CBD, as well as other compounds isolated from cannabis for the aforementioned reasons but will also include discussion over those studies where whole plant cannabis has been used. In this review we also consider the current challenges associated with the advancement of medicinal cannabis and its derived potential therapeutics into clinical applications.
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10
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Abstract
We demonstrated the presence of neural stem cells and/or progenitor cells in the adult human spinal cord. This chapter provides materials and methods to harvest high-quality samples of thoracolumbar, lumbar, and sacral adult human spinal cord and human dorsal root ganglia isolated from brain-dead patients who had agreed before passing to donate their bodies to science for therapeutic and scientific advances. The methods to culture precursor cells from the adult human spinal cord are also described.
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11
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Sánchez-Salcedo JA, Cabrera MME, Molina-Jiménez T, Cortes-Altamirano JL, Alfaro-Rodríguez A, Bonilla-Jaime H. Depression and Pain: use of antidepressant. Curr Neuropharmacol 2021; 20:384-402. [PMID: 34151765 PMCID: PMC9413796 DOI: 10.2174/1570159x19666210609161447] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 04/03/2021] [Accepted: 04/03/2021] [Indexed: 11/24/2022] Open
Abstract
Background: Emotional disorders are common comorbid affectations that exacerbate the severity and persistence of chronic pain. Specifically, depressive symptoms can lead to an excessive duration and intensity of pain. Clinical and preclinical studies have been focused on the underlying mechanisms of chronic pain and depression comorbidity and the use of antidepressants to reduce pain. Aim: This review provides an overview of the comorbid relationship of chronic pain and depression, the clinical and pre-clinical studies performed on the neurobiological aspects of pain and depression, and the use of antidepressants as analgesics. Methods: A systematic search of literature databases was conducted according to pre-defined criteria. The authors independently conducted a focused analysis of the full-text articles. Results: Studies suggest that pain and depression are highly intertwined and may co-exacerbate physical and psychological symptoms. One important biochemical basis for pain and depression focuses on the serotonergic and norepinephrine system, which have been shown to play an important role in this comorbidity. Brain structures that codify pain are also involved in mood. It is evident that using serotonergic and norepinephrine antidepressants are strategies commonly employed to mitigate pain Conclusion: Literature indicates that pain and depression impact each other and play a prominent role in the development and maintenance of other chronic symptoms. Antidepressants continue to be a major therapeutic tool for managing chronic pain. Tricyclic antidepressants (TCAs) are more effective in reducing pain than Selective Serotonin Reuptake Inhibitors (SSRIs) and Serotonin-Noradrenaline Reuptake Inhibitors (SNRIs).
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Affiliation(s)
- José Armando Sánchez-Salcedo
- Doctorado en Ciencias Biológicas y de la Salud. Universidad Autónoma Metropolitana-Iztapalapa, UAM-I, Apartado Postal 55 535, C.P. 09340, Ciudad de México, Mexico
| | - Maribel Maetizi Estevez Cabrera
- Doctorado en Ciencias Biológicas y de la Salud. Universidad Autónoma Metropolitana-Iztapalapa, UAM-I, Apartado Postal 55 535, C.P. 09340, Ciudad de México, Mexico
| | - Tania Molina-Jiménez
- Facultad de Química Farmacéutica Biológica, Universidad Veracruzana. Circuito Gonzálo Aguirre Beltrán Sn, Zona Universitaria. C.P. 91090 Xalapa-Enríquez
| | - José Luis Cortes-Altamirano
- División de Neurociencias, Instituto Nacional de Rehabilitación "Luis Guillermo Ibarra Ibarra", Secretaría de Salud, Ciudad de México, Mexico
| | - Alfonso Alfaro-Rodríguez
- División de Neurociencias, Instituto Nacional de Rehabilitación "Luis Guillermo Ibarra Ibarra", Secretaría de Salud, Ciudad de México, Mexico
| | - Herlinda Bonilla-Jaime
- Departamento de Biología de la Reproducción, Universidad Autónoma Metropolitana-Iztapalapa. Apartado Postal 55 535, C.P. 09340, Ciudad de México, Mexico
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Pizzolato C, Gunduz MA, Palipana D, Wu J, Grant G, Hall S, Dennison R, Zafonte RD, Lloyd DG, Teng YD. Non-invasive approaches to functional recovery after spinal cord injury: Therapeutic targets and multimodal device interventions. Exp Neurol 2021; 339:113612. [DOI: 10.1016/j.expneurol.2021.113612] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 12/24/2020] [Accepted: 01/11/2021] [Indexed: 12/16/2022]
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13
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Buspirone for functional improvement after acute traumatic spinal cord injury: a propensity score-matched cohort study. Spinal Cord 2021; 59:563-570. [PMID: 33495579 DOI: 10.1038/s41393-020-00606-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 11/22/2020] [Accepted: 12/02/2020] [Indexed: 11/08/2022]
Abstract
STUDY DESIGN Retrospective analysis of treated inpatients compared to expected neurorecovery from a propensity score-matched national database cohort. OBJECTIVE Evaluate the effectiveness of buspirone on clinical neurorecovery following traumatic SCI when started during acute inpatient rehabilitation. SETTING University-based hospital in Boston, USA. METHODS Chart review yielded thirty-one individuals with acute, traumatic SCI treated with buspirone during inpatient rehabilitation from 2011-2017. Propensity score matching to a cohort of individuals from the spinal cord injury model systems (SCIMS) national database was completed. Changes in upper extremity motor score (UEMS), lower extremity motor score (LEMS), American Spinal Injury Association Impairment Scale (AIS), neurological level of injury (NLI), and functional impairment measure (FIM) from admission to discharge and discharge to 1 year were computed and compared between matched pairs (buspirone and mean national SCIMs cohort). A local control cohort not treated with buspirone was similarly compared to a matched mean national SCIMs group to identify location-specific effects. RESULTS From admission to discharge from inpatient rehabilitation, 95% confidence intervals of changes in UEMS (-2.43 to +2.78), LEMS (-1.02 to +6.02), AIS (-0.04 to +0.35), NLI (-0.42 to +1.08), and FIM (-4.42 to +6.40) were not significantly different between those individuals who received buspirone and their propensity-matched SCIMS cohort. Similarly, changes in these metrics were not significantly different at 1-year follow up. Buspirone group individuals with initial clinically complete SCI demonstrated a higher 1-year conversion rate to incomplete injury (6 out of 14; 42.9%) compared to the matched national SCIMS cohort (14 out of 70; 21.2%, p = 0.047) though this was not significantly different from non-buspirone local controls (p = 0.25). CONCLUSIONS Retrospective analysis shows no statistically significant difference in gross markers of neurorecovery following acute traumatic SCI when buspirone is initiated indiscriminately during acute inpatient rehabilitation. In individuals with clinically complete SCI, findings suggest possible increased rates of 1-year conversion to incomplete injury.
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Lin CY, Sparks A, Lee YS. Improvement of lower urinary tract function by a selective serotonin 5-HT 1A receptor agonist, NLX-112, after chronic spinal cord injury. Exp Neurol 2020; 332:113395. [PMID: 32615138 DOI: 10.1016/j.expneurol.2020.113395] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/15/2020] [Accepted: 06/25/2020] [Indexed: 12/20/2022]
Abstract
Spinal cord injury (SCI) above the lumbosacral level results in lower urinary tract dysfunction, including (1) detrusor hyperreflexia, wherein bladder compliance is low, and (2) a lack of external urethral sphincter (EUS) control, leading to detrusor-sphincter dyssynergia (DSD) with poor voiding efficiency. Experimental studies in animals have shown a dense innervation of serotonergic (5-HT) fibers and multiple 5-HT receptors in the spinal reflex circuits that control voiding function. Here, we investigated the efficacy of NLX-112 (a.k.a. befiradol or F13640), in regulating lower urinary tract function after T8 contusive SCI in rats. NLX-112 is a very potent, highly-selective, and fully efficacious 5-HT1A receptor agonist, which has been developed for the treatment of L-DOPA-induced dyskinesia in Parkinson's disease patients. We performed urodynamics tests and external urethral sphincter electromyogram recordings to assess lower urinary tract function while NLX-112 was infused through the femoral vein in rats with chronic complete SCI or contusive SCI. The dose response studies indicated that NLX-112 was able to improve voiding behavior by regulating both detrusor and EUS activity. These included improvements in voiding efficiency, reduction of detrusor hyperactivity, and phasic activity of EUS during the micturition period. In addition, the application of a selective 5-HT1A receptor antagonist, WAY100635, reversed the improved detrusor and EUS activity elicited by NLX-112. In summary, the current data suggest that pharmacological activation of 5-HT1A receptors by NLX-112 may constitute a novel therapeutic strategy to treat neurogenic bladder after SCI.
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Affiliation(s)
- Ching-Yi Lin
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Alexander Sparks
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Yu-Shang Lee
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
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15
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Flaive A, Cabelguen JM, Ryczko D. The serotonin reuptake blocker citalopram destabilizes fictive locomotor activity in salamander axial circuits through 5-HT 1A receptors. J Neurophysiol 2020; 123:2326-2342. [PMID: 32401145 DOI: 10.1152/jn.00179.2020] [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] [Indexed: 01/03/2023] Open
Abstract
Serotoninergic (5-HT) neurons are powerful modulators of spinal locomotor circuits. Most studies on 5-HT modulation focused on the effect of exogenous 5-HT and these studies provided key information about the cellular mechanisms involved. Less is known about the effects of increased release of endogenous 5-HT with selective serotonin reuptake inhibitors. In mammals, such molecules were shown to destabilize the fictive locomotor output of spinal limb networks through 5-HT1A receptors. However, in tetrapods little is known about the effects of increased 5-HT release on the locomotor output of axial networks, which are coordinated with limb circuits during locomotion from basal vertebrates to mammals. Here, we examined the effect of citalopram on fictive locomotion generated in axial segments of isolated spinal cords in salamanders, a tetrapod where raphe 5-HT reticulospinal neurons and intraspinal 5-HT neurons are present as in other vertebrates. Using electrophysiological recordings of ventral roots, we show that fictive locomotion generated by bath-applied glutamatergic agonists is destabilized by citalopram. Citalopram-induced destabilization was prevented by a 5-HT1A receptor antagonist, whereas a 5-HT1A receptor agonist destabilized fictive locomotion. Using immunofluorescence experiments, we found 5-HT-positive fibers and varicosities in proximity with motoneurons and glutamatergic interneurons that are likely involved in rhythmogenesis. Our results show that increasing 5-HT release has a deleterious effect on axial locomotor activity through 5-HT1A receptors. This is consistent with studies in limb networks of turtle and mouse, suggesting that this part of the complex 5-HT modulation of spinal locomotor circuits is common to limb and axial networks in limbed vertebrates.NEW & NOTEWORTHY Little is known about the modulation exerted by endogenous serotonin on axial locomotor circuits in tetrapods. Using axial ventral root recordings in salamanders, we found that a serotonin reuptake blocker destabilized fictive locomotor activity through 5-HT1A receptors. Our anatomical results suggest that serotonin is released on motoneurons and glutamatergic interneurons possibly involved in rhythmogenesis. Our study suggests that common serotoninergic mechanisms modulate axial motor circuits in amphibians and limb motor circuits in reptiles and mammals.
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Affiliation(s)
- Aurélie Flaive
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Jean-Marie Cabelguen
- Neurocentre Magendie, INSERM U 862, Université de Bordeaux, Bordeaux Cedex, France
| | - Dimitri Ryczko
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Quebec, Canada.,Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, Quebec, Canada.,Institut de Pharmacologie de Sherbrooke, Sherbrooke, Quebec, Canada.,Centre des neurosciences de Sherbrooke, Sherbrooke, Quebec, Canada
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16
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Bardoni R. Serotonergic Modulation of Nociceptive Circuits in Spinal Cord Dorsal Horn. Curr Neuropharmacol 2020; 17:1133-1145. [PMID: 31573888 PMCID: PMC7057206 DOI: 10.2174/1570159x17666191001123900] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 08/28/2019] [Accepted: 09/26/2019] [Indexed: 01/12/2023] Open
Abstract
Background: Despite the extensive number of studies performed in the last 50 years, aimed at describing the role of serotonin and its receptors in pain modulation at the spinal cord level, several aspects are still not entirely understood. The interpretation of these results is often complicated by the use of different pain models and animal species, together with the lack of highly selective agonists and antagonists binding to serotonin receptors. Method: In this review, a search has been conducted on studies investigating the modulatory action exerted by serotonin on specific neurons and circuits in the spinal cord dorsal horn. Particular attention has been paid to studies employing electro-physiological techniques, both in vivo and in vitro. Conclusion: The effects of serotonin on pain transmission in dorsal horn depend on several factors, including the type of re-ceptors activated and the populations of neurons involved. Recently, studies performed by activating and/or recording from identified neurons have importantly contributed to the understanding of serotonergic modulation on dorsal horn circuits.
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Affiliation(s)
- Rita Bardoni
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, 41125, Italy
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17
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Haleem DJ. Targeting Serotonin1A Receptors for Treating Chronic Pain and Depression. Curr Neuropharmacol 2020; 17:1098-1108. [PMID: 31418663 PMCID: PMC7057205 DOI: 10.2174/1570159x17666190811161807] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 07/31/2019] [Accepted: 08/02/2019] [Indexed: 02/07/2023] Open
Abstract
The association of chronic pain with depression is becoming increasingly recognized. Treating both the conditions together is essential for an effective treatment outcome. In this regard, it is important to identify a shared mechanism involved in the association of chronic pain with depression. Central serotonin (5-hydroxytryptamine; 5-HT) neurotransmission has long been known to participate in the processing of signals related to pain. It also plays a key role in the pathogenesis and treatment of depression. Although functional responses to serotonin are mediated via the activation of multiple receptor types and subtypes, the 5-HT1A subtype is involved in the processing of nociception as well as the pathogenesis and treatment of depression. This receptor is located presynaptically, as an autoreceptor, on the perikaryon and dendritic spines of serotonin-containing neurons. It is also expressed as a heteroreceptor on neurons receiving input from serotonergic neurons. This arti-cle targets the 5-HT1A receptors to show that indiscriminate activation of pre and postsynaptic 5-HT1A receptors is likely to produce no therapeutic benefits; biased activation of the 5-HT heteroreceptors may be a useful strategy for treating chronic pain and depression individually as well as in a comorbid condition.
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Affiliation(s)
- Darakhshan Jabeen Haleem
- Neuroscience Research Laboratory, Dr. Panjwani Center for Molecular Medicine & Drug Research (PCMD), International Center for Chemical and Biological Science (ICCBS), University of Karachi, Karachi 75270, Pakistan
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18
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Perrin FE, Noristani HN. Serotonergic mechanisms in spinal cord injury. Exp Neurol 2019; 318:174-191. [PMID: 31085200 DOI: 10.1016/j.expneurol.2019.05.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 05/07/2019] [Accepted: 05/08/2019] [Indexed: 12/12/2022]
Abstract
Spinal cord injury (SCI) is a tragic event causing irreversible losses of sensory, motor, and autonomic functions, that may also be associated with chronic neuropathic pain. Serotonin (5-HT) neurotransmission in the spinal cord is critical for modulating sensory, motor, and autonomic functions. Following SCI, 5-HT axons caudal to the lesion site degenerate, and the degree of axonal degeneration positively correlates with lesion severity. Rostral to the lesion, 5-HT axons sprout, irrespective of the severity of the injury. Unlike callosal fibers and cholinergic projections, 5-HT axons are more resistant to an inhibitory milieu and undergo active sprouting and regeneration after central nervous system (CNS) traumatism. Numerous studies suggest that a chronic increase in serotonergic neurotransmission promotes 5-HT axon sprouting in the intact CNS. Moreover, recent studies in invertebrates suggest that 5-HT has a pro-regenerative role in injured axons. Here we present a brief description of 5-HT discovery, 5-HT innervation of the CNS, and physiological functions of 5-HT in the spinal cord, including its role in controlling bladder function. We then present a comprehensive overview of changes in serotonergic axons after CNS damage, and discuss their plasticity upon altered 5-HT neurotransmitter levels. Subsequently, we provide an in-depth review of therapeutic approaches targeting 5-HT neurotransmission, as well as other pre-clinical strategies to promote an increase in re-growth of 5-HT axons, and their functional consequences in SCI animal models. Finally, we highlight recent findings signifying the direct role of 5-HT in axon regeneration and suggest strategies to further promote robust long-distance re-growth of 5-HT axons across the lesion site and eventually achieve functional recovery following SCI.
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Affiliation(s)
- Florence Evelyne Perrin
- University of Montpellier, Montpellier, F-34095 France; INSERM, U1198, Montpellier, F-34095 France; EPHE, Paris, F-75014 France
| | - Harun Najib Noristani
- Shriners Hospitals Pediatric Research Center, Center for Neural Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA.
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19
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Trueblood CT, Iredia IW, Collyer ES, Tom VJ, Hou S. Development of Cardiovascular Dysfunction in a Rat Spinal Cord Crush Model and Responses to Serotonergic Interventions. J Neurotrauma 2019; 36:1478-1486. [PMID: 30362884 DOI: 10.1089/neu.2018.5962] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Selection of a proper spinal cord injury (SCI) rat model to study therapeutic effects of cell transplantation is imperative for research in cardiovascular functional recovery, due to the local harsh milieu inhibiting cell growth. We recently found that a crushed spinal cord lesion can minimize fibrotic scarring and grafted cell death compared with open-dura injuries. To determine if this SCI model is applicable for studying cardiovascular recovery, we examined hemodynamic consequences following crushed SCI and tested cardiovascular responses to serotonin (5-HT) or dopamine (DA) receptor agonists. Using a radio-telemetric system, multiple cardiovascular parameters were recorded prior to, 2, and 4 weeks after SCI, including resting mean arterial pressure (MAP) and heart rate (HR), as well as spontaneous or colorectal distension (CRD)-induced autonomic dysreflexia (AD). The results showed that this injury caused tachycardia at rest as well as the occurrence of spontaneous or artificially induced dysreflexic events. Four weeks post-injury, specific activation of 5-HT2A receptors by subcutaneous (s.c.) or intrathecal (i.t.) delivery of Dimethoxy-4-iodoamphetamine (DOI) remarkably increased resting MAP levels in a dose-dependent fashion. During CRD-induced autonomic dysreflexia, systemic administration of DOI alleviated the severity of bradycardia responsive to episodic hypertension. In contrast, selective stimulation of 5-HT1A receptors with 8-OH-DPAT or non-selective activation of DA receptors with apomorphine did not affect cardiovascular performance. Thus, crush injuries induce cardiovascular abnormalities in rats that are sensitive to 5-HT2A receptor stimulation, indicating a reliable SCI model to study how cell-based approaches impact the severity of autonomic dysreflexia and identify a possible target for pharmacological interventions.
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Affiliation(s)
- Cameron T Trueblood
- Spinal Cord Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Idiata W Iredia
- Spinal Cord Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Eileen S Collyer
- Spinal Cord Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Veronica J Tom
- Spinal Cord Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Shaoping Hou
- Spinal Cord Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania
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20
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Spinal cord organogenesis model reveals role of Flk1 + cells in self-organization of neural progenitor cells into complex spinal cord tissue. Stem Cell Res 2018; 33:156-165. [PMID: 30368192 DOI: 10.1016/j.scr.2018.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 08/02/2018] [Accepted: 09/05/2018] [Indexed: 12/15/2022] Open
Abstract
A platform for studying spinal cord organogenesis in vivo where embryonic stem cell (ESC)-derived neural progenitor cells (NPC) self-organize into spinal cord-like tissue after transplantation in subarachnoid space of the spinal cord has been described. We advance the applicability of this platform by imaging in vivo the formed graft through T2w magnetic resonance imaging (MRI). Furthermore, we used diffusion tensor imaging (DTI) to verify the stereotypical organization of the graft showing that it mimics the host spinal cord. Within the graft white matter (WM) we identified astrocytes that form glial limitans, myelinating oligodendrocytes, and myelinated axons with paranodes. Within the graft grey matter (GM) we identified cholinergic, glutamatergic, serotonergic and dopaminergic neurons. Furthermore, we demonstrate the presence of ESC-derived complex vasculature that includes the presence of blood brain barrier. In addition to the formation of mature spinal cord tissue, we describe factors that drive this process. Specifically, we identify Flk1+ cells as necessary for spinal cord formation, and synaptic connectivity with the host spinal cord and formation of host-graft chimeric vasculature as contributing factors. This model can be used to study spinal cord organogenesis, and as an in vivo drug discovery platform for screening potential therapeutic compounds and their toxicity.
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21
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Serotonin-1A receptor dependent modulation of pain and reward for improving therapy of chronic pain. Pharmacol Res 2018; 134:212-219. [DOI: 10.1016/j.phrs.2018.06.030] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 06/12/2018] [Accepted: 06/29/2018] [Indexed: 12/24/2022]
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22
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Li S, Sun C, Rong P, Zhai X, Zhang J, Baker M, Wang S. Auricular vagus nerve stimulation enhances central serotonergic function and inhibits diabetic neuropathy development in Zucker fatty rats. Mol Pain 2018; 14:1744806918787368. [PMID: 29921169 PMCID: PMC6055102 DOI: 10.1177/1744806918787368] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Painful neuropathy is a frequent comorbidity in diabetes. Zucker diabetic fatty (fa/fa) rats develop type 2 diabetes spontaneously with aging and show nociceptive hypersensitivity at the age of 13 weeks. In preclinical and clinical studies, the treatment of diabetic neuropathy is challenging, but complementary medicine such as transcutaneous auricular vagus nerve stimulation (taVNS) appears beneficial to the relief of neuropathic pain. However, the mechanism behind the effectiveness of taVNS remains unclear. In this study, we show that daily 30-min taVNS (2/15 Hz, 2 mA) for consecutive 27 days effectively inhibited the development of nociceptive hypersensitivity in Zucker diabetic fatty rats as detected by thermal hyperalgesia and mechanical allodynia in hindpaw. We also demonstrated that this beneficial effect in nociceptive behavior is related to an elevated serotonin (5-HT) plasma concentration and an upregulated expression of 5-HT receptor type 1A (5-HT1AR) in hypothalamus. We conclude that daily 30-min taVNS sessions lessen diabetic neuropathy development by enhancing serotonergic function in genetically diabetes prone individuals. Perspective This article presents taVNS as a new approach to inhibit the development of diabetic neuropathy in genetically prone individuals. This approach could potentially help clinicians who seek to avoid the complication of neuropathic pain in diabetic patient or to relieve the pain if there was one.
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Affiliation(s)
- Shaoyuan Li
- 1 Department of Anatomy, Xinxiang Medical University, Xinxiang, Henan, China.,2 Department of Physiology, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Chunli Sun
- 1 Department of Anatomy, Xinxiang Medical University, Xinxiang, Henan, China
| | - Peijing Rong
- 2 Department of Physiology, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xu Zhai
- 2 Department of Physiology, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jinling Zhang
- 2 Department of Physiology, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Max Baker
- 3 Department of Anesthesia, University of Iowa, Iowa City, IA, USA
| | - Shuxing Wang
- 1 Department of Anatomy, Xinxiang Medical University, Xinxiang, Henan, China.,3 Department of Anesthesia, University of Iowa, Iowa City, IA, USA
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Newman-Tancredi A, Bardin L, Auclair A, Colpaert F, Depoortère R, Varney M. NLX-112, a highly selective 5-HT 1A receptor agonist, mediates analgesia and antidepressant-like activity in rats via spinal cord and prefrontal cortex 5-HT 1A receptors, respectively. Brain Res 2018; 1688:1-7. [DOI: 10.1016/j.brainres.2018.03.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 03/05/2018] [Accepted: 03/13/2018] [Indexed: 01/03/2023]
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Sałat K, Kołaczkowski M, Furgała A, Rojek A, Śniecikowska J, Varney MA, Newman-Tancredi A. Antinociceptive, antiallodynic and antihyperalgesic effects of the 5-HT 1A receptor selective agonist, NLX-112 in mouse models of pain. Neuropharmacology 2017; 125:181-188. [PMID: 28751195 DOI: 10.1016/j.neuropharm.2017.07.022] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 06/11/2017] [Accepted: 07/22/2017] [Indexed: 01/02/2023]
Abstract
BACKGROUND AND PURPOSE NLX-112 (a.k.a. befiradol, F13640) is a drug candidate intended for the treatment of l-DOPA-induced dyskinesia. It is a highly selective serotonin 5-HT1A receptor full agonist which has been previously tested in a variety of models of CNS effects including analgesic activity in rat. Its activity in mouse models of pain has not been previously investigated. EXPERIMENTAL APPROACH The activity of NLX-112 was tested in mouse models of acute pain (hot plate), tonic pain (intraplantar formalin test), in the oxaliplatin-induced neuropathic pain model of chemotherapy-induced peripheral neuropathy and in the streptozotocin (STZ)-induced model of painful diabetic neuropathy. KEY RESULTS The main findings indicate that (i) NLX-112 was markedly active in the formalin test with potent reduction of paw licking in both phases of the test (minimal effective dose (MED) 0.5 mg/kg i.p. and p.o. in acute phase, and 0.1 mg/kg i.p. and 1 mg/kg p.o. in late phase). The effects of NLX-112 in this test were completely abolished by the selective 5-HT1A receptor antagonist, WAY100635; (ii) NLX-112 was active in the hot plate test and in the oxaliplatin-induced neuropathic pain model of chemotherapy-induced peripheral neuropathy, but at markedly higher doses (MED 2.5 mg/kg i.p.); (iii) NLX-112 was least active in the STZ-induced model of painful diabetic neuropathy (MED 5 mg/kg i.p.); (iv) NLX-112 did not affect locomotor activity. CONCLUSIONS AND IMPLICATIONS NLX-112 may have significant potential for treatment of tonic pain but may be less promising as a candidate for treatment of chemotherapy-induced or diabetic neuropathic pain.
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Affiliation(s)
- Kinga Sałat
- Chair of Pharmacodynamics, Jagiellonian University, Medical College, Medyczna 9 St., 30-688 Krakow, Poland.
| | - Marcin Kołaczkowski
- Chair of Pharmaceutical Chemistry, Jagiellonian University, Medical College, Medyczna 9 St., 30-688 Krakow, Poland
| | - Anna Furgała
- Chair of Pharmacodynamics, Jagiellonian University, Medical College, Medyczna 9 St., 30-688 Krakow, Poland
| | - Adriana Rojek
- Chair of Pharmacodynamics, Jagiellonian University, Medical College, Medyczna 9 St., 30-688 Krakow, Poland
| | - Joanna Śniecikowska
- Chair of Pharmaceutical Chemistry, Jagiellonian University, Medical College, Medyczna 9 St., 30-688 Krakow, Poland
| | - Mark A Varney
- Neurolixis Inc., 34145 Pacific Coast Highway #504, Dana Point, CA 92629, USA
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Côté MP, Murray M, Lemay MA. Rehabilitation Strategies after Spinal Cord Injury: Inquiry into the Mechanisms of Success and Failure. J Neurotrauma 2016; 34:1841-1857. [PMID: 27762657 DOI: 10.1089/neu.2016.4577] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Body-weight supported locomotor training (BWST) promotes recovery of load-bearing stepping in lower mammals, but its efficacy in individuals with a spinal cord injury (SCI) is limited and highly dependent on injury severity. While animal models with complete spinal transections recover stepping with step-training, motor complete SCI individuals do not, despite similarly intensive training. In this review, we examine the significant differences between humans and animal models that may explain this discrepancy in the results obtained with BWST. We also summarize the known effects of SCI and locomotor training on the muscular, motoneuronal, interneuronal, and supraspinal systems in human and non-human models of SCI and address the potential causes for failure to translate to the clinic. The evidence points to a deficiency in neuronal activation as the mechanism of failure, rather than muscular insufficiency. While motoneuronal and interneuronal systems cannot be directly probed in humans, the changes brought upon by step-training in SCI animal models suggest a beneficial re-organization of the systems' responsiveness to descending and afferent feedback that support locomotor recovery. The literature on partial lesions in humans and animal models clearly demonstrate a greater dependency on supraspinal input to the lumbar cord in humans than in non-human mammals for locomotion. Recent results with epidural stimulation that activates the lumbar interneuronal networks and/or increases the overall excitability of the locomotor centers suggest that these centers are much more dependent on the supraspinal tonic drive in humans. Sensory feedback shapes the locomotor output in animal models but does not appear to be sufficient to drive it in humans.
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Affiliation(s)
- Marie-Pascale Côté
- 1 Department of Neurobiology and Anatomy, Drexel University College of Medicine , Philadelphia, Pennsylvania
| | - Marion Murray
- 1 Department of Neurobiology and Anatomy, Drexel University College of Medicine , Philadelphia, Pennsylvania
| | - Michel A Lemay
- 2 Department of Bioengineering, Temple University , Philadelphia, Pennsylvania
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Combination of grafted Schwann cells and lentiviral-mediated prevention of glial scar formation improve recovery of spinal cord injured rats. J Chem Neuroanat 2016; 76:48-60. [DOI: 10.1016/j.jchemneu.2015.12.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 11/26/2015] [Accepted: 12/25/2015] [Indexed: 01/03/2023]
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Burke LK, Heisler LK. 5-hydroxytryptamine medications for the treatment of obesity. J Neuroendocrinol 2015; 27:389-98. [PMID: 25925636 DOI: 10.1111/jne.12287] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 04/23/2015] [Accepted: 04/23/2015] [Indexed: 12/11/2022]
Abstract
The central 5-hydroxytryptamine (5-HT; serotonin) system represents a fundamental component of the brain's control of energy homeostasis. Medications targeting the 5-HT pathway have been at the forefront of obesity treatment for the past 15 years. Pharmacological agents targeting 5-HT receptors (5-HTR), in combination with genetic models of 5-HTR manipulation, have uncovered a role for specific 5-HTRs in energy balance and reveal the 5-HT2 C R as the principal 5-HTR mediating this homeostatic process. Capitalising on this neurophysiological machinery, 5-HT2 C R agonists improve obesity and glycaemic control in patient populations. The underlying therapeutic mechanism has been probed using model systems and appears to be achieved primarily through 5-HT2 C R modulation of the brain melanocortin circuit via activation of pro-opiomelanocortin neurones signalling at melanocortin4 receptors. Thus, 5-HT2 C R agonists offer a means to improve obesity and type 2 diabetes, which are conditions that now represent global challenges to human health.
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Affiliation(s)
- L K Burke
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - L K Heisler
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK
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Ghosh M, Pearse DD. The role of the serotonergic system in locomotor recovery after spinal cord injury. Front Neural Circuits 2015; 8:151. [PMID: 25709569 PMCID: PMC4321350 DOI: 10.3389/fncir.2014.00151] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 12/28/2014] [Indexed: 11/30/2022] Open
Abstract
Serotonin (5-HT), a monoamine neurotransmitter synthesized in various populations of brainstem neurons, plays an important role in modulating the activity of spinal networks involved in vertebrate locomotion. Following spinal cord injury (SCI) there is a disruption of descending serotonergic projections to spinal motor areas, which results in a subsequent depletion in 5-HT, the dysregulation of 5-HT transporters as well as the elevated expression, super-sensitivity and/or constitutive auto-activation of specific 5-HT receptors. These changes in the serotonergic system can produce varying degrees of locomotor dysfunction through to paralysis. To date, various approaches targeting the different components of the serotonergic system have been employed to restore limb coordination and improve locomotor function in experimental models of SCI. These strategies have included pharmacological modulation of serotonergic receptors, through the administration of specific 5-HT receptor agonists, or by elevating the 5-HT precursor 5-hydroxytryptophan, which produces a global activation of all classes of 5-HT receptors. Stimulation of these receptors leads to the activation of the locomotor central pattern generator (CPG) below the site of injury to facilitate or improve the quality and frequency of movements, particularly when used in concert with the activation of other monoaminergic systems or coupled with electrical stimulation. Another approach has been to employ cell therapeutics to replace the loss of descending serotonergic input to the CPG, either through transplanted fetal brainstem 5-HT neurons at the site of injury that can supply 5-HT to below the level of the lesion or by other cell types to provide a substrate at the injury site for encouraging serotonergic axon regrowth across the lesion to the caudal spinal cord for restoring locomotion.
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Affiliation(s)
- Mousumi Ghosh
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine Miami, FL, USA ; Department of Neurological Surgery, University of Miami Miller School of Medicine Miami, FL, USA
| | - Damien D Pearse
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine Miami, FL, USA ; Department of Neurological Surgery, University of Miami Miller School of Medicine Miami, FL, USA ; The Neuroscience Program, University of Miami Miller School of Medicine Miami, FL, USA ; The Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine Miami, FL, USA
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Cornide-Petronio ME, Fernández-López B, Barreiro-Iglesias A, Rodicio MC. Traumatic injury induces changes in the expression of the serotonin 1A receptor in the spinal cord of lampreys. Neuropharmacology 2014; 77:369-78. [PMID: 24490228 DOI: 10.1016/j.neuropharm.2013.10.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
After spinal cord injury (SCI) in mammals, the loss of serotonin coming from the brainstem reduces the excitability of motor neurons and leads to a compensatory overexpression of serotonin receptors. Despite the key role of the serotonin receptor 1a in the control of locomotion, little attention has been put in the study of this receptor after SCI. In contrast to mammals, lampreys recover locomotion after a complete SCI, so, studies in this specie could help to understand events that lead to recovery of function. Here, we showed that in lampreys there is an acute increase in the expression of the serotonin 1A receptor transcript (5-ht1a) after SCI and a few weeks later expression levels go back to normal rostrally and caudally to the lesion. Overexpression of the 5-ht1a in rostral levels after SCI has not been reported in mammals, suggesting that this could be part of the plastic events that lead to the recovery of function in lampreys. The analysis of changes in 5-ht1a expression by zones (periventricular region and horizontally extended grey matter) showed that they followed the same pattern of changes detected in the spinal cord as a whole, with the exception of the caudal periventricular layer, where no significant differences were observed between control and experimental animals at any time post lesion. This suggests that different molecular signals act on the periventricular cells of the rostral and caudal regions to injury site and thus affecting their response to the injury in terms of expression of the 5-ht1a.
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Serotonergic transmission after spinal cord injury. J Neural Transm (Vienna) 2014; 122:279-95. [PMID: 24866695 DOI: 10.1007/s00702-014-1241-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Accepted: 05/06/2014] [Indexed: 12/27/2022]
Abstract
Changes in descending serotonergic innervation of spinal neural activity have been implicated in symptoms of paralysis, spasticity, sensory disturbances and pain following spinal cord injury (SCI). Serotonergic neurons possess an enhanced ability to regenerate or sprout after many types of injury, including SCI. Current research suggests that serotonine (5-HT) release within the ventral horn of the spinal cord plays a critical role in motor function, and activation of 5-HT receptors mediates locomotor control. 5-HT originating from the brain stem inhibits sensory afferent transmission and associated spinal reflexes; by abolishing 5-HT innervation SCI leads to a disinhibition of sensory transmission. 5-HT denervation supersensitivity is one of the key mechanisms underlying the increased motoneuron excitability that occurs after SCI, and this hyperexcitability has been demonstrated to underlie the pathogenesis of spasticity after SCI. Moreover, emerging evidence implicates serotonergic descending facilitatory pathways from the brainstem to the spinal cord in the maintenance of pathologic pain. There are functional relevant connections between the descending serotonergic system from the rostral ventromedial medulla in the brainstem, the 5-HT receptors in the spinal dorsal horn, and the descending pain facilitation after tissue and nerve injury. This narrative review focussed on the most important studies that have investigated the above-mentioned effects of impaired 5-HT-transmission in humans after SCI. We also briefly discussed the promising therapeutical approaches with serotonergic drugs, monoclonal antibodies and intraspinal cell transplantation.
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Johnstone JT, Morton PD, Jayakumar AR, Johnstone AL, Gao H, Bracchi-Ricard V, Pearse DD, Norenberg MD, Bethea JR. Inhibition of NADPH oxidase activation in oligodendrocytes reduces cytotoxicity following trauma. PLoS One 2013; 8:e80975. [PMID: 24260524 PMCID: PMC3834306 DOI: 10.1371/journal.pone.0080975] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 10/08/2013] [Indexed: 11/18/2022] Open
Abstract
Spinal cord injury is a debilitating neurological disorder that initiates a cascade of cellular events that result in a period of secondary damage that can last for months after the initial trauma. The ensuing outcome of these prolonged cellular perturbations is the induction of neuronal and glial cell death through excitotoxic mechanisms and subsequent free radical production. We have previously shown that astrocytes can directly induce oligodendrocyte death following trauma, but the mechanisms regulating this process within the oligodendrocyte remain unclear. Here we provide evidence demonstrating that astrocytes directly regulate oligodendrocyte death after trauma by inducing activation of NADPH oxidase within oligodendrocytes. Spinal cord injury resulted in a significant increase in oxidative damage which correlated with elevated expression of the gp91 phox subunit of the NADPH oxidase enzyme. Immunohistochemical analysis confirmed the presence of gp91 phox in oligodendrocytes in vitro and at 1 week following spinal cord injury. Exposure of oligodendrocytes to media from injured astrocytes resulted in an increase in oligodendrocyte NADPH oxidase activity. Inhibition of NADPH oxidase activation was sufficient to attenuate oligodendrocyte death in vitro and at 1 week following spinal cord injury, suggesting that excitotoxicity of oligodendrocytes after trauma is dependent on the intrinsic activation of the NADPH oxidase enzyme. Acute administration of the NADPH oxidase inhibitor apocynin and the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate channel blocker 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo[f]quinoxaline-2,3-dione significantly improved locomotor behavior and preserved descending axon fibers following spinal cord injury. These studies lead to a better understanding of oligodendrocyte death after trauma and identify potential therapeutic targets in disorders involving demyelination and oligodendrocyte death.
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Affiliation(s)
- Joshua T. Johnstone
- The Miami Project to Cure Paralysis, University of Miami, Miami, Florida, United States of America
| | - Paul D. Morton
- The Miami Project to Cure Paralysis, University of Miami, Miami, Florida, United States of America
| | - Arumugam R. Jayakumar
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, Florida, United States of America
| | - Andrea L. Johnstone
- The Miami Project to Cure Paralysis, University of Miami, Miami, Florida, United States of America
| | - Han Gao
- The Miami Project to Cure Paralysis, University of Miami, Miami, Florida, United States of America
| | - Valerie Bracchi-Ricard
- The Miami Project to Cure Paralysis, University of Miami, Miami, Florida, United States of America
| | - Damien D. Pearse
- The Miami Project to Cure Paralysis, University of Miami, Miami, Florida, United States of America
- Department of Neurosurgery, Miller School of Medicine, University of Miami, Miami, Florida, United States of America
| | - Michael D. Norenberg
- Department of Pathology, Miller School of Medicine, University of Miami, Miami, Florida, United States of America
- Department of Biochemistry and Molecular Biology, University of Miami, Miami, Florida, United States of America
- South Florida Foundation for Research & Education Inc, Veterans Affairs Medical Center, Miami, Florida, United States of America
| | - John R. Bethea
- The Miami Project to Cure Paralysis, University of Miami, Miami, Florida, United States of America
- Department of Neurosurgery, Miller School of Medicine, University of Miami, Miami, Florida, United States of America
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, Florida, United States of America
- * E-mail:
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Hanrieder J, Malmberg P, Lindberg OR, Fletcher JS, Ewing AG. Time-of-flight secondary ion mass spectrometry based molecular histology of human spinal cord tissue and motor neurons. Anal Chem 2013; 85:8741-8. [PMID: 23947367 DOI: 10.1021/ac401830m] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Secondary ion mass spectrometry is a powerful method for imaging biological samples with high spatial resolution. Whole section time-of-flight-secondary ion mass spectrometry (TOF-SIMS) scans and multivariate data analysis have been performed on the human spinal cord in order to delineate anatomical regions of interest based on their chemical distribution pattern. TOF-SIMS analysis of thoracic spinal cord sections was performed at 5 μm resolution within 2 h. Multivariate image analysis by means of principal component analysis and maximum auto correlation factor analysis resulted in detection of more than 400 m/z peaks that were found to be significantly changed. Here, the results show characteristic biochemical distributions that are well in line with major histological regions, including gray and white matter. As an approach for iterative segmentation, we further evaluated previously outlined regions of interest as identified by multivariate image analysis. Here, further discrimination of the gray matter into ventral, lateral, and dorsal neuroanatomical regions was observed. TOF-SIMS imaging has been carried out at submicrometer resolution obtaining localization and characterization of spinal motor neurons based on their chemical fingerprint, including neurotransmitter precursors that serve as molecular indicators for motor neuron integrity. Thus, TOF-SIMS can be used as an approach for chemical histology and pathology. TOF-SIMS holds immense potential for investigating the subcellular mechanisms underlying spinal cord related diseases including chronic pain and amyotrophic lateral sclerosis.
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Affiliation(s)
- Jörg Hanrieder
- National Center for Imaging Mass Spectrometry, Gothenburg University and Chalmers University of Technology , Sweden
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Bauchet L, Lonjon N, Vachiery-Lahaye F, Boularan A, Privat A, Hugnot JP. Isolation and culture of precursor cells from the adult human spinal cord. Methods Mol Biol 2013; 1059:87-93. [PMID: 23934836 DOI: 10.1007/978-1-62703-574-3_8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Our group recently provided evidence for the presence of neural stem cells and/or progenitor cells in the adult human spinal cord. In this chapter, we review materials and methods to harvest high-quality samples of thoracolumbar, lumbar, and sacral adult human spinal cord from brain-dead patients who had agreed to donate their bodies to science for therapeutic and scientific advances. The methods to culture precursor cells from the adult human spinal cord are also described.
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Affiliation(s)
- Luc Bauchet
- Département de Neurochirurgie, Centre Hospitalier Universitaire, Hôpital Gui de Chauliac, Montpellier, France
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Del Tredici K, Braak H. Spinal cord lesions in sporadic Parkinson's disease. Acta Neuropathol 2012; 124:643-64. [PMID: 22926675 DOI: 10.1007/s00401-012-1028-y] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Revised: 07/25/2012] [Accepted: 07/25/2012] [Indexed: 12/14/2022]
Abstract
In this autopsy-based study, α-synuclein immunohistochemistry and lipofuscin pigment-Nissl architectonics in serial sections of 100 μm thickness were used to investigate the spinal cords and brains of 46 individuals: 28 patients with clinically and neuropathologically confirmed Parkinson's disease, 6 cases with incidental Lewy body disease, and 12 age-matched controls. α-Synuclein inclusions (particulate aggregations, Lewy neurites/bodies) in the spinal cord were present between neuropathological stages 2-6 in all cases whose brains were staged for Parkinson's disease-related synucleinopathy. The only individuals who did not have Lewy pathology in the spinal cord were a single stage 1 case (incidental Lewy body disease) and all controls. Because the Parkinson's disease-related lesions were observable in the spinal cord only after Lewy pathology was seen in the brain, it could be concluded that, within the central nervous system, sporadic Parkinson's disease does not begin in the spinal cord. In addition: (1) α-Synuclein-immunoreactive axons clearly predominated over Lewy bodies throughout the spinal cord and were visible in medial and anterior portions of the anterolateral funiculus. Their terminal axons formed dense α-synuclein-immunoreactive networks in the gray matter and were most conspicuous in the lateral portions of layers 1, 7, and in the cellular islands of layer 9. (2) Notably, this axonopathy increased remarkably in density from cervicothoracic segments to lumbosacral segments of the cord. (3) Topographically, it is likely that the spinal cord α-synuclein immunoreactive axonal networks represent descending projections from the supraspinal level setting nuclei (locus coeruleus, lower raphe nuclei, magnocellular portions of the reticular formation). (4) Following the appearance of the spinal cord axonal networks, select types of projection neurons in the spinal cord gray matter displayed α-synuclein-immunoreactive inclusions: chiefly, nociceptive neurons of the dorsal horn in layer 1, sympathetic and parasympathetic preganglionic neurons in layer 7, the cellular pools of α-motoneurons in layer 9, and the smaller motoneurons in Onuf's nucleus in layer 9 (ventral horn). The spinal cord lesions may contribute to clinical symptoms (e.g., pain, constipation, poor balance, lower urinary tract complaints, and sexual dysfunction) that occur during the premotor and motor phases of sporadic Parkinson's disease.
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Affiliation(s)
- Kelly Del Tredici
- Clinical Neuroanatomy Section, Department of Neurology, Center for Biomedical Research, University of Ulm, Germany.
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Dentel C, Palamiuc L, Henriques A, Lannes B, Spreux-Varoquaux O, Gutknecht L, René F, Echaniz-Laguna A, Gonzalez de Aguilar JL, Lesch KP, Meininger V, Loeffler JP, Dupuis L. Degeneration of serotonergic neurons in amyotrophic lateral sclerosis: a link to spasticity. ACTA ACUST UNITED AC 2012; 136:483-93. [PMID: 23114367 DOI: 10.1093/brain/aws274] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Spasticity is a common and disabling symptom observed in patients with central nervous system diseases, including amyotrophic lateral sclerosis, a disease affecting both upper and lower motor neurons. In amyotrophic lateral sclerosis, spasticity is traditionally thought to be the result of degeneration of the upper motor neurons in the cerebral cortex, although degeneration of other neuronal types, in particular serotonergic neurons, might also represent a cause of spasticity. We performed a pathology study in seven patients with amyotrophic lateral sclerosis and six control subjects and observed that central serotonergic neurons suffer from a degenerative process with prominent neuritic degeneration, and sometimes loss of cell bodies in patients with amyotrophic lateral sclerosis. Moreover, distal serotonergic projections to spinal cord motor neurons and hippocampus systematically degenerated in patients with amyotrophic lateral sclerosis. In SOD1 (G86R) mice, a transgenic model of amyotrophic lateral sclerosis, serotonin levels were decreased in brainstem and spinal cord before onset of motor symptoms. Furthermore, there was noticeable atrophy of serotonin neuronal cell bodies along with neuritic degeneration at disease onset. We hypothesized that degeneration of serotonergic neurons could underlie spasticity in amyotrophic lateral sclerosis and investigated this hypothesis in vivo using tail muscle spastic-like contractions in response to mechanical stimulation as a measure of spasticity. In SOD1 (G86R) mice, tail muscle spastic-like contractions were observed at end-stage. Importantly, they were abolished by 5-hydroxytryptamine-2b/c receptors inverse agonists. In line with this, 5-hydroxytryptamine-2b receptor expression was strongly increased at disease onset. In all, we show that serotonergic neurons degenerate during amyotrophic lateral sclerosis, and that this might underlie spasticity in mice. Further research is needed to determine whether inverse agonists of 5-hydroxytryptamine-2b/c receptors could be of interest in treating spasticity in patients with amyotrophic lateral sclerosis.
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Lindstedt F, Karshikoff B, Schalling M, Olgart Höglund C, Ingvar M, Lekander M, Kosek E. Serotonin-1A receptor polymorphism (rs6295) associated with thermal pain perception. PLoS One 2012; 7:e43221. [PMID: 22952650 PMCID: PMC3432037 DOI: 10.1371/journal.pone.0043221] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 07/18/2012] [Indexed: 02/08/2023] Open
Abstract
Background Serotonin (5-HT) is highly involved in pain regulation and serotonin-1A (5-HT1A) receptors are important in determining central 5-HT tone. Accordingly, variation in the 5-HT1A receptor gene (HTR1A) may contribute to inter-individual differences in human pain sensitivity. The minor G-allele of the HTR1A single nucleotide polymorphism (SNP) rs6295 attenuates firing of serotonergic neurons and reduces postsynaptic expression of the receptor. Experiments in rodents suggest that 5-HT1A-agonism modulates pain in opposite directions at mild compared to high noxious intensities. Based upon this and several other similar observations, we hypothesized that G-carriers would exhibit a relative hypoalgesia at mild thermal stimuli but tend towards hyperalgesia at higher noxious intensities. Methods Fourty-nine healthy individuals were selectively genotyped for rs6295. Heat- and cold-pain thresholds were assessed along with VAS-ratings of a range of suprathreshold noxious heat intensities (45°C–49°C). Nociceptive-flexion reflex (NFR) thresholds were also assessed. Results Volunteers did not deviate significantly from Hardy-Weinberg equilibrium. G-carriers were less sensitive to threshold-level thermal pain. This relative hypoalgesia was abolished at suprathreshold noxious intensities where G-carriers instead increased their ratings of heat-pain significantly more than C-homozygotes. No differences with regard to NFR-thresholds emerged. Conclusion/Significance To the best of our knowledge this is the first study of human pain perception on the basis of variation in HTR1A. The results illustrate the importance of including a range of stimulus intensities in assessments of pain sensitivity. In speculation, we propose that an attenuated serotonergic tone may be related to a ‘hypo- to hyperalgesic’ response-pattern. The involved mechanisms could be of clinical interest as variation in pain regulation is known to influence the risk of developing pain pathologies. Further investigations are therefore warranted.
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Affiliation(s)
- Fredrik Lindstedt
- Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden.
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