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Poulen G, Perrin FE. Advances in spinal cord injury: insights from non-human primates. Neural Regen Res 2024; 19:2354-2364. [PMID: 38526271 PMCID: PMC11090432 DOI: 10.4103/nrr.nrr-d-23-01505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 11/13/2023] [Accepted: 12/22/2023] [Indexed: 03/26/2024] Open
Abstract
Spinal cord injury results in significant sensorimotor deficits, currently, there is no curative treatment for the symptoms induced by spinal cord injury. Basic and pre-clinical research on spinal cord injury relies on the development and characterization of appropriate animal models. These models should replicate the symptoms observed in human, allowing for the exploration of functional deficits and investigation into various aspects of physiopathology of spinal cord injury. Non-human primates, due to their close phylogenetic association with humans, share more neuroanatomical, genetic, and physiological similarities with humans than rodents. Therefore, the responses to spinal cord injury in nonhuman primates most likely resemble the responses to traumatism in humans. In this review, we will discuss nonhuman primate models of spinal cord injury, focusing on in vivo assessments, including behavioral tests, magnetic resonance imaging, and electrical activity recordings, as well as ex vivo histological analyses. Additionally, we will present therapeutic strategies developed in non-human primates and discuss the unique specificities of non-human primate models of spinal cord injury.
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Affiliation(s)
- Gaetan Poulen
- University of Montpellier, INSERM, EPHE, Montpellier, France
- Department of Neurosurgery, Gui de Chauliac Hospital, Montpellier University Medical Center, Montpellier, France
| | - Florence E. Perrin
- University of Montpellier, INSERM, EPHE, Montpellier, France
- Institut Universitaire de France (IUF), Paris, France
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2
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Sawada M, Yoshino-Saito K, Ninomiya T, Oishi T, Yamashita T, Onoe H, Takada M, Nishimura Y, Isa T. Reorganization of Corticospinal Projections after Prominent Recovery of Finger Dexterity from Partial Spinal Cord Injury in Macaque Monkeys. eNeuro 2023; 10:ENEURO.0209-23.2023. [PMID: 37468328 PMCID: PMC10408784 DOI: 10.1523/eneuro.0209-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 07/11/2023] [Indexed: 07/21/2023] Open
Abstract
We investigated morphologic changes in the corticospinal tract (CST) to understand the mechanism underlying recovery of hand function after lesion of the CST at the C4/C5 border in seven macaque monkeys. All monkeys exhibited prominent recovery of precision grip success ratio within a few months. The trajectories and terminals of CST from the contralesional (n = 4) and ipsilesional (n = 3) hand area of primary motor cortex (M1) were investigated at 5-29 months after the injury using an anterograde neural tracer, biotinylated dextran amine (BDA). Reorganization of the CST was assessed by counting the number of BDA-labeled axons and bouton-like swellings in the gray and white matters. Rostral to the lesion (at C3), the number of axon collaterals of the descending axons from both contralesional and ipsilesional M1 entering the ipsilesional and contralesional gray matter, respectively, were increased. Caudal to the lesion (at C8), axons originating from the contralesional M1, descending in the preserved gray matter around the lesion, and terminating in ipsilesional Laminae VI/VII and IX were observed. In addition, axons and terminals from the ipsilesional M1 increased in the ipsilesional Lamina IX after recrossing the midline, which were not observed in intact monkeys. Conversely, axons originating from the ipsilesional M1 and directed toward the contralesional Lamina VII decreased. These results suggest that multiple reorganizations of the corticospinal projections to spinal segments both rostral and caudal to the lesion originating from bilateral M1 underlie a prominent recovery in long-term after spinal cord injury.
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Affiliation(s)
- Masahiro Sawada
- Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
- Department of Neurosurgery, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Kimika Yoshino-Saito
- Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
| | - Taihei Ninomiya
- Systems Neuroscience, Primate Research Institute, Kyoto University, Inuyama 484-8506, Japan
| | - Takao Oishi
- Systems Neuroscience, Primate Research Institute, Kyoto University, Inuyama 484-8506, Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Saitama 332-0012, Japan
| | - Toshihide Yamashita
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Saitama 332-0012, Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Saitama 332-0012, Japan
| | - Hirotaka Onoe
- Human Brain Research Center, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Masahiko Takada
- Systems Neuroscience, Primate Research Institute, Kyoto University, Inuyama 484-8506, Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Saitama 332-0012, Japan
| | - Yukio Nishimura
- Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Saitama 332-0012, Japan
- Neural Prosthetics Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
- The graduate University for Advanced Studies (SOKENDAI), Hayama 240-0193, Japan
- Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Saitama 332-0012, Japan
| | - Tadashi Isa
- Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Saitama 332-0012, Japan
- Human Brain Research Center, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
- The graduate University for Advanced Studies (SOKENDAI), Hayama 240-0193, Japan
- Department of Neuroscience, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
- Institute for the Advanced Study of Human Biology (WPI-ASHBi), Kyoto University, Kyoto 606-8501, Japan
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Li Y, Zhang Y, Zhou W, Li R, Yu J, Gong L, Leng J, Lu F, Hou J, Chen H, Gao Q. Depression mediated the relationships between precentral-subcortical causal links and motor recovery in spinal cord injury patients. Cereb Cortex 2023:7034218. [PMID: 36775985 DOI: 10.1093/cercor/bhad035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 01/13/2023] [Accepted: 01/14/2023] [Indexed: 02/14/2023] Open
Abstract
Depression after brain damage may impede the motivation and consequently influence the motor recovery after spinal cord injury (SCI); however, the neural mechanism underlying the psychological effects remains unclear. This study aimed to examine the casual connectivity changes of the emotion-motivation-motor circuit and the potential mediating effects of depression on motor recovery after SCI. Using the resting-state functional magnetic resonance imaging data of 35 SCI patients (24 good recoverers, GR and 11 poor recoverers, PR) and 32 healthy controls (HC), the results from the conditional Granger causality (GC) analysis demonstrated that the GR group exhibited sparser emotion-motivation-motor GC network compared with the HC and PR groups, though the in-/out-degrees of the emotion subnetwork and the motor subnetwork were relatively balanced in the HC and GR group. The PR group showed significantly inhibitory causal links from amygdala to supplementary motor area and from precentral gyrus to nucleus accumbens compared with GR group. Further mediation analysis revealed the indirect effect of the 2 causal connections on motor function recovery via depression severity. Our findings provide further evidence of abnormal causal connectivity in emotion-motivation-motor circuit in SCI patients and highlight the importance of emotion intervention for motor function recovery after SCI.
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Affiliation(s)
- Yan Li
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Mathematical Sciences, University of Electronic Science and Technology of China, Chengdu, No. 2006, Xiyuan Ave, West Hi-Tech Zone, 611731, P.R. China
| | - Yang Zhang
- The Southwest Hospital, Third Military Medical University, Chongqing, Gaotanyan Road, Shapingba District, 400038, P.R. China
| | - Weiqi Zhou
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Mathematical Sciences, University of Electronic Science and Technology of China, Chengdu, No. 2006, Xiyuan Ave, West Hi-Tech Zone, 611731, P.R. China
| | - Rong Li
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, No. 2006, Xiyuan Ave, West Hi-Tech Zone, 611731, P.R. China
| | - Jiali Yu
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Mathematical Sciences, University of Electronic Science and Technology of China, Chengdu, No. 2006, Xiyuan Ave, West Hi-Tech Zone, 611731, P.R. China
| | - Lisha Gong
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Mathematical Sciences, University of Electronic Science and Technology of China, Chengdu, No. 2006, Xiyuan Ave, West Hi-Tech Zone, 611731, P.R. China
| | - Jinsong Leng
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Mathematical Sciences, University of Electronic Science and Technology of China, Chengdu, No. 2006, Xiyuan Ave, West Hi-Tech Zone, 611731, P.R. China
| | - Fengmei Lu
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Mathematical Sciences, University of Electronic Science and Technology of China, Chengdu, No. 2006, Xiyuan Ave, West Hi-Tech Zone, 611731, P.R. China
| | - Jingming Hou
- The Southwest Hospital, Third Military Medical University, Chongqing, Gaotanyan Road, Shapingba District, 400038, P.R. China
| | - Huafu Chen
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, No. 2006, Xiyuan Ave, West Hi-Tech Zone, 611731, P.R. China.,The Center of Psychosomatic Medicine, Sichuan Provincial Center for Mental Health, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Yihuan Road, Qingyang District, 610072, P.R. China
| | - Qing Gao
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Mathematical Sciences, University of Electronic Science and Technology of China, Chengdu, No. 2006, Xiyuan Ave, West Hi-Tech Zone, 611731, P.R. China
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Hu X, Zhang Y, Wang L, Ding J, Li M, Li H, Wu L, Zeng Z, Xia H. Microglial activation in the motor cortex mediated NLRP3-related neuroinflammation and neuronal damage following spinal cord injury. Front Cell Neurosci 2022; 16:956079. [PMID: 36339822 PMCID: PMC9630363 DOI: 10.3389/fncel.2022.956079] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 07/27/2022] [Indexed: 12/30/2023] Open
Abstract
Spinal cord injury (SCI) is a traumatic event that can lead to neurodegeneration. Neuronal damage in the primary motor cortex (M1) can hinder motor function recovery after SCI. However, the exact mechanisms involved in neuronal damage after SCI remain incompletely understood. In this study, we found that microglia were activated in M1 after SCI, which triggered Nod-like receptor protein 3 (NLRP3) related chronic neuroinflammation and neuronal damage in vivo. Meanwhile, treatment with the microglia inhibitor minocycline reduced inflammation-induced neuronal damage in M1, protected the integrity of the motor conduction pathway, and promoted motor function recovery. Furthermore, we simulated chronic inflammation in M1 after SCI by culturing the primary neurons in primary microglia-conditioned medium, and observed that the injury to the primary neurons also occurred in vitro; however, as observed in vivo, these effects could be mitigated by minocycline treatment. Our results indicated that microglial activation in M1 mediates NLRP3-related neuroinflammation and causes the injury to M1 neurons, thereby impairing the integrity of the motor conduction pathway and inhibiting motor function recovery. These findings might contribute to the identification of novel therapeutic strategies for SCI.
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Affiliation(s)
- Xvlei Hu
- Department of Neurosurgery, Shanxi Provincial People's Hospital, Taiyuan, China
- School of Clinical Medicine, Ningxia Medical University, Yinchuan, China
- Ningxia Key Laboratory of Craniocerebral Diseases, Ningxia Medical University, Yinchuan, China
| | - Yifan Zhang
- School of Clinical Medicine, Ningxia Medical University, Yinchuan, China
- Ningxia Human Stem Cell Research Institute, General Hospital of Ningxia Medical University, Yinchuan, China
| | - Lei Wang
- Department of Neurosurgery, Henan Provincial People's Hospital, Zhengzhou, China
| | - Jiangwei Ding
- Ningxia Key Laboratory of Craniocerebral Diseases, Ningxia Medical University, Yinchuan, China
| | - Mei Li
- School of Clinical Medicine, Ningxia Medical University, Yinchuan, China
- Ningxia Key Laboratory of Craniocerebral Diseases, Ningxia Medical University, Yinchuan, China
| | - Hailiang Li
- Ningxia Key Laboratory of Craniocerebral Diseases, Ningxia Medical University, Yinchuan, China
| | - Liang Wu
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China
| | - Zhong Zeng
- School of Clinical Medicine, Ningxia Medical University, Yinchuan, China
- Ningxia Key Laboratory of Craniocerebral Diseases, Ningxia Medical University, Yinchuan, China
| | - Hechun Xia
- Ningxia Human Stem Cell Research Institute, General Hospital of Ningxia Medical University, Yinchuan, China
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China
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Suzuki M, Nishimura Y. The ventral striatum contributes to the activity of the motor cortex and motor outputs in monkeys. Front Syst Neurosci 2022; 16:979272. [PMID: 36211590 PMCID: PMC9540202 DOI: 10.3389/fnsys.2022.979272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 08/10/2022] [Indexed: 11/13/2022] Open
Abstract
The ventral striatum (VSt) is thought to be involved in the vigor of motivated behavior and is suggested to be a limbic-motor interface between limbic areas involved in motivational processes and neural circuits regulating behavioral outputs. However, there is little direct evidence demonstrating the involvement of the VSt in motor control for motivated behaviors. To clarify the functional role of the VSt in motor control, we investigated the effect of reversible pharmacological inactivation of the VSt on the oscillatory activity of the sensorimotor cortices and motor outputs in two macaque monkeys. VSt inactivation reduced movement-related activities of the primary motor cortex and premotor area at 15–120 Hz and increased those at 5–7 Hz. These changes were accompanied by reduced torque outputs but had no effect on the correct performance rate. The present study provides direct evidence that the VSt regulates activities of the motor cortices and motor output.
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Affiliation(s)
- Michiaki Suzuki
- Division of Behavioral Development, Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Japan
- Department of Physiological Sciences, School of Life Science, SOKENDAI, Hayama, Japan
- Department of Neuroscience, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Japan Society for the Promotion of Science, Tokyo, Japan
- Neural Prosthetics Project, Department of Brain and Neurosciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Yukio Nishimura
- Division of Behavioral Development, Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Japan
- Department of Physiological Sciences, School of Life Science, SOKENDAI, Hayama, Japan
- Department of Neuroscience, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Neural Prosthetics Project, Department of Brain and Neurosciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
- *Correspondence: Yukio Nishimura
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Ninomiya T, Nakagawa H, Inoue KI, Nishimura Y, Oishi T, Yamashita T, Takada M. Origin of Multisynaptic Corticospinal Pathway to Forelimb Segments in Macaques and Its Reorganization After Spinal Cord Injury. Front Neural Circuits 2022; 16:847100. [PMID: 35463202 PMCID: PMC9020432 DOI: 10.3389/fncir.2022.847100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Accepted: 03/01/2022] [Indexed: 11/25/2022] Open
Abstract
Removal of the monosynaptic corticospinal pathway (CSP) terminating within the forelimb segments severely impairs manual dexterity. Functional recovery from the monosynaptic CSP lesion can be achieved through the remaining multisynaptic CSP toward the forelimb segments. In the present study, we applied retrograde transsynaptic labeling with rabies virus to a monkey model of spinal cord injury. By injecting the virus into the spinal forelimb segments immediately after the monosynaptic CSP lesion, we showed that the contralateral primary motor cortex (M1), especially its caudal and bank region (so-called “new” M1), was the principal origin of the CSP linking the motor cortex to the spinal forelimb segments disynaptically (disynaptic CSP). This forms a striking contrast to the architecture of the monosynaptic CSP that involves extensively other motor-related areas, together with M1. Next, the rabies injections were made at the recovery period of 3 months after the monosynaptic CSP lesion. The second-order labeled neurons were located in the ipsilateral as well as in the contralateral “new” M1. This indicates that the disynaptic CSP input from the ipsilateral “new” M1 is recruited during the motor recovery from the monosynaptic CSP lesion. Our results suggest that the disynaptic CSP is reorganized to connect the ipsilateral “new” M1 to the forelimb motoneurons for functional compensation after the monosynaptic CSP lesion.
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Affiliation(s)
- Taihei Ninomiya
- Systems Neuroscience Section, Primate Research Institute, Kyoto University, Inuyama, Japan
- Japan Agency for Medical Research and Development (AMED), Core Research for Evolutional Science and Technology (CREST), Tokyo, Japan
- Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Japan
- Department of Physiological Sciences, School of Life Sciences, The Graduate University for Advanced Studies (SOKENDAI), Hayama, Japan
- *Correspondence: Taihei Ninomiya,
| | - Hiroshi Nakagawa
- Systems Neuroscience Section, Primate Research Institute, Kyoto University, Inuyama, Japan
- Japan Agency for Medical Research and Development (AMED), Core Research for Evolutional Science and Technology (CREST), Tokyo, Japan
- Department of Molecular Neuroscience, World Premier International Immunology Frontier Research Center, Osaka University, Suita, Japan
| | - Ken-ichi Inoue
- Systems Neuroscience Section, Primate Research Institute, Kyoto University, Inuyama, Japan
- Japan Agency for Medical Research and Development (AMED), Core Research for Evolutional Science and Technology (CREST), Tokyo, Japan
| | - Yukio Nishimura
- Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Japan
- Department of Physiological Sciences, School of Life Sciences, The Graduate University for Advanced Studies (SOKENDAI), Hayama, Japan
- Neural Prosthetics Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Takao Oishi
- Systems Neuroscience Section, Primate Research Institute, Kyoto University, Inuyama, Japan
- Japan Agency for Medical Research and Development (AMED), Core Research for Evolutional Science and Technology (CREST), Tokyo, Japan
| | - Toshihide Yamashita
- Japan Agency for Medical Research and Development (AMED), Core Research for Evolutional Science and Technology (CREST), Tokyo, Japan
- Department of Molecular Neuroscience, World Premier International Immunology Frontier Research Center, Osaka University, Suita, Japan
| | - Masahiko Takada
- Systems Neuroscience Section, Primate Research Institute, Kyoto University, Inuyama, Japan
- Japan Agency for Medical Research and Development (AMED), Core Research for Evolutional Science and Technology (CREST), Tokyo, Japan
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Suzuki M, Inoue KI, Nakagawa H, Ishida H, Kobayashi K, Isa T, Takada M, Nishimura Y. A multisynaptic pathway from the ventral midbrain toward spinal motoneurons in monkeys. J Physiol 2022; 600:1731-1752. [PMID: 35122444 PMCID: PMC9306604 DOI: 10.1113/jp282429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 01/10/2022] [Indexed: 12/02/2022] Open
Abstract
Abstract Motivation boosts motor performance. Activity of the ventral midbrain (VM), consisting of the ventral tegmental area (VTA), the substantia nigra pars compacta (SNc) and the retrorubral field (RRF), plays an important role in processing motivation. However, little is known about the neural substrate bridging the VM and the spinal motor output. We hypothesized that the VM might exert a modulatory influence over the descending motor pathways. By retrograde transneuronal labelling with rabies virus, we demonstrated the existence of multisynaptic projections from the VM to the cervical enlargement in monkeys. The distribution pattern of spinal projection neurons in the VM exhibited a caudorostral gradient, in that the RRF and the caudal part of the SNc contained more retrogradely labelled neurons than the VTA and the rostral part of the SNc. Electrical stimulation of the VM induced muscle responses in the contralateral forelimb with a delay of a few milliseconds following the responses of the ipsilateral primary motor cortex (M1). The magnitude and number of evoked muscle responses were associated with the stimulus intensity and number of pulses. The muscle responses were diminished during M1 inactivation. Thus, the present study has identified a multisynaptic VM–spinal pathway that is mediated, at least in part, by the M1 and might play a pivotal role in modulatory control of the spinal motor output. Key points Motivation to obtain reward is thought to boost motor performance, and activity in the ventral midbrain is important to the motivational process. Little is known about a neural substrate bridging the ventral midbrain and the spinal motor output. Retrograde trans‐synaptic experiments revealed that the ventral midbrain projects multisynaptically to the spinal cord in macaque monkeys. Ventral midbrain activation by electrical stimulation generated cortical activity in the motor cortex and forelimb muscle activity. A multisynaptic ventral midbrain–spinal pathway most probably plays a pivotal role in modulatory control of the spinal motor output.
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Affiliation(s)
- Michiaki Suzuki
- Neural Prosthetics Project, Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo, 156-8506, Japan.,Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8585, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa, 240-0193, Japan
| | - Ken-Ichi Inoue
- Systems Neuroscience Section, Primate Research Institute, Kyoto University, Inuyama, Aichi, 484-8506, Japan
| | - Hiroshi Nakagawa
- Systems Neuroscience Section, Primate Research Institute, Kyoto University, Inuyama, Aichi, 484-8506, Japan.,Present address: Department of Molecular Neuroscience, World Premier International Immunology Frontier Research Center, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Hiroaki Ishida
- Neural Prosthetics Project, Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo, 156-8506, Japan.,Present address: Schizophrenia Research Project, Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo, 156-8506, Japan
| | - Kenta Kobayashi
- Section of Viral Vector Development, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8585, Japan
| | - Tadashi Isa
- Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8585, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa, 240-0193, Japan.,Section of Viral Vector Development, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8585, Japan.,Department of Neuroscience, Graduate School of Medicine, Kyoto University, Sakyo, Kyoto, 606-8501, Japan.,Institute for the Advanced Study of Human Biology (WPI-ASHBi), Kyoto University, Sakyo, Kyoto, 606-8501, Japan
| | - Masahiko Takada
- Systems Neuroscience Section, Primate Research Institute, Kyoto University, Inuyama, Aichi, 484-8506, Japan
| | - Yukio Nishimura
- Neural Prosthetics Project, Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo, 156-8506, Japan.,Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8585, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa, 240-0193, Japan
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Xie Z, Zhou W, Liu D, Li MH. Animal Models of Cerebral Changes Secondary to Spinal Cord Injury. World Neurosurg 2021; 145:244-50. [PMID: 32980567 DOI: 10.1016/j.wneu.2020.09.103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 09/18/2020] [Accepted: 09/19/2020] [Indexed: 11/20/2022]
Abstract
Spinal cord injuries (SCIs) are difficult to treat. The first animal SCI model (featuring the dropping of a weight) was established by Allen in 1911, and other animal models have been developed since then. Most animal studies have focused only on the molecular features of SCIs, which remain disputed. Recently, it has become clear that SCI may trigger mental and cognitive disorders, however, and brain changes secondary to SCI are under investigation. No consensus on an optimal animal model for cerebral research has emerged. We discuss the appropriate SCI models for studying secondary brain changes.
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