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Doulames VM, Marquardt LM, Hefferon ME, Baugh NJ, Suhar RA, Wang AT, Dubbin KR, Weimann JM, Palmer TD, Plant GW, Heilshorn SC. Custom-engineered hydrogels for delivery of human iPSC-derived neurons into the injured cervical spinal cord. Biomaterials 2024; 305:122400. [PMID: 38134472 PMCID: PMC10846596 DOI: 10.1016/j.biomaterials.2023.122400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 09/18/2023] [Accepted: 11/11/2023] [Indexed: 12/24/2023]
Abstract
Cervical damage is the most prevalent type of spinal cord injury clinically, although few preclinical research studies focus on this anatomical region of injury. Here we present a combinatorial therapy composed of a custom-engineered, injectable hydrogel and human induced pluripotent stem cell (iPSC)-derived deep cortical neurons. The biomimetic hydrogel has a modular design that includes a protein-engineered component to allow customization of the cell-adhesive peptide sequence and a synthetic polymer component to allow customization of the gel mechanical properties. In vitro studies with encapsulated iPSC-neurons were used to select a bespoke hydrogel formulation that maintains cell viability and promotes neurite extension. Following injection into the injured cervical spinal cord in a rat contusion model, the hydrogel biodegraded over six weeks without causing any adverse reaction. Compared to cell delivery using saline, the hydrogel significantly improved the reproducibility of cell transplantation and integration into the host tissue. Across three metrics of animal behavior, this combinatorial therapy significantly improved sensorimotor function by six weeks post transplantation. Taken together, these findings demonstrate that design of a combinatorial therapy that includes a gel customized for a specific fate-restricted cell type can induce regeneration in the injured cervical spinal cord.
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Affiliation(s)
- V M Doulames
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA
| | - L M Marquardt
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA
| | - M E Hefferon
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA
| | - N J Baugh
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA
| | - R A Suhar
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA
| | - A T Wang
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA
| | - K R Dubbin
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA
| | - J M Weimann
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - T D Palmer
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - G W Plant
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, 94305, USA.
| | - S C Heilshorn
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA.
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Wang S, Zhang LC, Fu HT, Deng JH, Xu GX, Li T, Ji XR, Tang PF. Epidural electrical stimulation effectively restores locomotion function in rats with complete spinal cord injury. Neural Regen Res 2021; 16:573-579. [PMID: 32985490 PMCID: PMC7996032 DOI: 10.4103/1673-5374.290905] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Epidural electrical stimulation can restore limb motor function after spinal cord injury by reactivating the surviving neural circuits. In previous epidural electrical stimulation studies, single electrode sites and continuous tetanic stimulation have often been used. With this stimulation, the body is prone to declines in tolerance and locomotion coordination. In the present study, rat models of complete spinal cord injury were established by vertically cutting the spinal cord at the T8 level to eliminate disturbance from residual nerve fibers, and were then subjected to epidural electrical stimulation. The flexible extradural electrode had good anatomical topology and matched the shape of the spinal canal of the implanted segment. Simultaneously, the electrode stimulation site was able to be accurately applied to the L2–3 and S1 segments of the spinal cord. To evaluate the biocompatibility of the implanted epidural electrical stimulation electrodes, GFAP/Iba-1 double-labeled immunofluorescence staining was performed on the spinal cord below the electrodes at 7 days after the electrode implantation. Immunofluorescence results revealed no significant differences in the numbers or morphologies of microglia and astrocytes in the spinal cord after electrode implantation, and there was no activated Iba-1+ cell aggregation, indicating that the implant did not cause an inflammatory response in the spinal cord. Rat gait analysis showed that, at 3 days after surgery, gait became coordinated in rats with spinal cord injury under burst stimulation. The regained locomotion could clearly distinguish the support phase and the swing phase and dynamically adjust with the frequency of stimulus distribution. To evaluate the matching degree between the flexible epidural electrode (including three stimulation contacts), vertebral morphology, and the level of the epidural site of the stimulation electrode, micro-CT was used to scan the thoracolumbar vertebrae of rats before and after electrode implantation. Based on the experimental results of gait recovery using three-site stimulation electrodes at L2–3 and S1 combined with burst stimulation in a rat model of spinal cord injury, epidural electrical stimulation is a promising protocol that needs to be further explored. This study was approved by the Animal Ethics Committee of Chinese PLA General Hospital (approval No. 2019-X15-39) on April 19, 2019.
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Affiliation(s)
- Song Wang
- School of Medicine, Nankai University, Tianjin; Department of Orthopedics, Chinese PLA General Hospital, Beijing, China
| | - Li-Cheng Zhang
- Department of Orthopedics, Chinese PLA General Hospital, Beijing, China
| | - Hai-Tao Fu
- Department of Orthopedics, The Affiliated Hospital of Qingdao University, Qingdao, Shandong Province, China
| | - Jun-Hao Deng
- Department of Orthopedics, Chinese PLA General Hospital, Beijing, China
| | - Gao-Xiang Xu
- Department of Orthopedics, Chinese PLA General Hospital, Beijing, China
| | - Tong Li
- Characteristic Medical Center of the Chinese People's Armed Police Force, Tianjin, China
| | - Xin-Ran Ji
- Department of Orthopedics, Chinese PLA General Hospital, Beijing, China
| | - Pei-Fu Tang
- Department of Orthopedics, Chinese PLA General Hospital, Beijing, China
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Liu J, Yang Z, Wu X, Huang Z, Huang Z, Chen X, Liu Q, Jiang H, Zhu Q. Comparison of the anatomical morphology of cervical vertebrae between humans and macaques: related to a spinal cord injury model. Exp Anim 2020; 70:108-118. [PMID: 33071271 PMCID: PMC7887620 DOI: 10.1538/expanim.20-0018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Non-human primates are most suitable for generating cervical experimental models, and it is necessary to study the anatomy of the cervical spine in non-human primates when generating the models. The purpose of this study was to provide the anatomical parameters of the cervical spine and spinal cord in long-tailed macaques (Macaca fascicularis) as a basis for cervical spine-related experimental studies. Cervical spine specimens from 8 male adult subjects were scanned by micro-computed tomography, and an additional 10 live male subjects were scanned by magnetic resonance imaging. The measurements and parameters from them were compared to those of 12 male adult human subjects. Additionally, 10 live male subjects were scanned by magnetic resonance imaging, and the width and depth of the spinal cord and spinal canal and the thickness of the anterior and posterior cerebrospinal fluid were measured and compared to the relevant parameters of 10 male adult human subjects. The tendency of cervical parameters to change with segmental changes was similar between species. The vertebral body, spinal canal, and spinal cord were significantly flatter in the human subjects than in the long-tailed macaques. The cerebrospinal fluid space in the long-tailed macaques was smaller than that in the human subjects. The anatomical features of the cervical vertebrae of long-tailed macaques provide a reference for establishing a preclinical model of cervical spinal cord injury.
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Affiliation(s)
- Junhao Liu
- Division of Spinal Surgery, Department of Orthopaedics, Nanfang Hospital, Southern Medical University, 1838 North Guangzhou Avenue, Guangzhou, China
| | - Zhou Yang
- Division of Spinal Surgery, Department of Orthopaedics, Nanfang Hospital, Southern Medical University, 1838 North Guangzhou Avenue, Guangzhou, China
| | - Xiuhua Wu
- Division of Spinal Surgery, Department of Orthopaedics, Nanfang Hospital, Southern Medical University, 1838 North Guangzhou Avenue, Guangzhou, China
| | - Zucheng Huang
- Division of Spinal Surgery, Department of Orthopaedics, Nanfang Hospital, Southern Medical University, 1838 North Guangzhou Avenue, Guangzhou, China
| | - Zhiping Huang
- Division of Spinal Surgery, Department of Orthopaedics, Nanfang Hospital, Southern Medical University, 1838 North Guangzhou Avenue, Guangzhou, China
| | - Xushi Chen
- Division of Spinal Surgery, Department of Orthopaedics, Nanfang Hospital, Southern Medical University, 1838 North Guangzhou Avenue, Guangzhou, China
| | - Qi Liu
- Division of Spinal Surgery, Department of Orthopaedics, Nanfang Hospital, Southern Medical University, 1838 North Guangzhou Avenue, Guangzhou, China
| | - Hui Jiang
- Division of Spinal Surgery, Department of Orthopaedics, Nanfang Hospital, Southern Medical University, 1838 North Guangzhou Avenue, Guangzhou, China
| | - Qingan Zhu
- Division of Spinal Surgery, Department of Orthopaedics, Nanfang Hospital, Southern Medical University, 1838 North Guangzhou Avenue, Guangzhou, China
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Mattucci S, Speidel J, Liu J, Ramer MS, Kwon BK, Tetzlaff W, Oxland TR. Development of a traumatic cervical dislocation spinal cord injury model with residual compression in the rat. J Neurosci Methods 2019; 322:58-70. [PMID: 30951755 DOI: 10.1016/j.jneumeth.2019.03.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 03/12/2019] [Accepted: 03/15/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND Preclinical spinal cord injury models do not represent the wide range of biomechanical factors seen in human injuries, such as spinal level, injury mechanism, velocity of spinal cord impact, and residual compression. These factors may be responsible for differences observed between experimental and clinical study results, especially related to the controversial issue of timing of surgical decompression. NEW METHOD Somatosensory Evoked Potentials were used to: a) characterize residual compression depths in a dislocation model, and b) evaluate the physiological effect of whether or not the spinal cord was decompressed following the initial injury, prior to the application of residual compression. Modifications to vertebral clamps and the development of a novel surgical frame allowed us to conduct surgical and injury procedures in a controlled manner without the risk of additional damage to the spinal cord. Behavioural outcomes were evaluated following varying dislocation displacements, in addition to the survivability of 4 h of residual compression following a traumatic injury. RESULTS Residual compression immediately following the initial dislocation demonstrated significantly different electrophysiological response compared to when the residual compression was delayed. COMPARISON WITH EXISTING METHOD There are currently no other residual compression models that utilize a dislocation injury mechanism. Many residual compression studies have demonstrated the effectiveness of early decompression, however the compression of the spinal cord is often not representative of clinical traumatic injuries. Preclinical studies typically model residual compression using a sustained force through quasi-static application, when human injuries often occur at high velocities, followed by a sustained displacement occlusion of the spinal canal. CONCLUSIONS This study has validated several novel procedural approaches and injury parameters, and provided critical details to implement in the development of a traumatic cervical dislocation SCI model with residual compression.
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Affiliation(s)
- Stephen Mattucci
- Orthopaedic and Injury Biomechanics Group, Departments of Orthopaedics and Mechanical Engineering, International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
| | - Jason Speidel
- Orthopaedic and Injury Biomechanics Group, Departments of Orthopaedics and Mechanical Engineering, International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
| | - Jie Liu
- International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
| | - Matt S Ramer
- International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
| | - Brian K Kwon
- International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
| | - Thomas R Oxland
- Orthopaedic and Injury Biomechanics Group, Departments of Orthopaedics and Mechanical Engineering, International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
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Kim MJ, Kim YY, Chao JR, Park HS, Chang J, Oh D, Lee JJ, Kang TC, Suh JG, Lee JH. Comparing the Organs and Vasculature of the Head and Neck in Five Murine Species. ACTA ACUST UNITED AC 2017; 31:861-871. [PMID: 28882952 DOI: 10.21873/invivo.11140] [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: 06/23/2017] [Revised: 07/19/2017] [Accepted: 07/26/2017] [Indexed: 11/10/2022]
Abstract
BACKGROUND/AIM The purpose of the present study was to delineate the cervical and facial vascular and associated anatomy in five murine species, and compare them for optimal use in research studies focused on understanding the pathology and treatment of diseases in humans. MATERIALS AND METHODS The specific adult male animals examined were mice (C57BL/6J), rats (F344), mongolian gerbils (Merionesunguiculatus), hamsters (Syrian), and guinea pigs (Hartley). To stain the vasculature and organs, of the face and neck, each animal was systemically perfused using the vital stain, Trypan Blue. Following this step, the detailed anatomy of the head and neck could be easily visualized in all species. RESULTS Unique morphological characteristics were demonstrated by comparing the five species, including symmetry of the common carotid origin bilaterally in the Mongolian Gerbil, a large submandibular gland in the hamster and an enlarged buccal branch in the Guinea Pig. In reviewing the anatomical details, this staining technique proves superior for direct surgical visualization and identification. CONCLUSION The anatomical details provided through these five species atlas will help experimental researchers in the future to select the most appropriate animal model for specific laboratory studies aimed to improve our understanding and treatment of diseases in patients.
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Affiliation(s)
- Min Jae Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Yoo Yeon Kim
- Department of Medical Genetics, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Janet Ren Chao
- School of Medicine, George Washington University, Washington, DC, U.S.A
| | - Hae Sang Park
- Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Hallym University, Chuncheon, Republic of Korea.,Institute of New Frontier Research, Hallym University College of Medicine, Chuncheon, Republic of Korea
| | - Jiwon Chang
- Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Hallym University, Chuncheon, Republic of Korea.,Institute of New Frontier Research, Hallym University College of Medicine, Chuncheon, Republic of Korea
| | - Dawoon Oh
- Department of Anesthesiology and Pain Medicine, Dongtan Sacred Heart Hospital, Hallym University, Dongtan, Republic of Korea
| | - Jae Jun Lee
- Institute of New Frontier Research, Hallym University College of Medicine, Chuncheon, Republic of Korea.,Department of Anesthesiology and Pain Medicine, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Tae Chun Kang
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Jun-Gyo Suh
- Department of Medical Genetics, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Jun Ho Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Hallym University, Chuncheon, Republic of Korea .,Institute of New Frontier Research, Hallym University College of Medicine, Chuncheon, Republic of Korea
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Wu J, Xue J, Huang R, Zheng C, Cui Y, Rao S. A rabbit model of lumbar distraction spinal cord injury. Spine J 2016; 16:643-58. [PMID: 26704859 DOI: 10.1016/j.spinee.2015.12.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 11/04/2015] [Accepted: 12/07/2015] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Excessive spinal distraction is a major cause of distraction spinal cord injury (SCI) during spinal deformity correction surgery. However, the lack of animal models of gradable and replicable distraction SCI has hampered research about how it occurs and how it can be prevented. The rabbit is a suitable choice for a model because it is more similar to humans than the rat, the most often used for studies of distraction SCI. The rabbit is readily acquired and reasonably affordable to maintain. PURPOSE The study aims to develop a gradable and replicable animal model of human lumbar distraction SCI. STUDY DESIGN This is an animal laboratory study. METHODS We built a spine distractor designed to vary the percentage of spine distraction by changing the movement between the bony landmarks of the spine. Anesthetized rabbits underwent surgery to expose the vertebral segments from T12 through L4. The distractor was mounted onto the T12 and L4 vertebral segments, and distraction was effected by turning the distractor's central screw to 0% (control), 10%, 20%, or 30% of the length from the L1 to the L4 vertebral segments, with eight rabbits in each group. Cortical somatosensory evoked potentials were recorded, and neurologic function was evaluated before the distractor was mounted and after the distractor was dismounted. The rabbits were killed, and spinal cord samples were taken for biochemical, histopathologic, and stereologic studies. RESULTS With increasing percentage distraction, the extent of distraction SCI increased as measured by recordings of cortical somatosensory evoked potentials, neurologic function, and biochemical, histopathologic, and stereologic studies. CONCLUSIONS Our model can be widely applied to studies of the causes of and treatment for distraction SCI.
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Affiliation(s)
- Ji Wu
- Orthopedic Department, Air Force General Hospital of Chinese People's Liberation Army, No 30 Fucheng Rd, Beijing 100142, China
| | - Jing Xue
- Orthopedic Department, Air Force General Hospital of Chinese People's Liberation Army, No 30 Fucheng Rd, Beijing 100142, China.
| | - Rongrong Huang
- Orthopedic Department, Air Force General Hospital of Chinese People's Liberation Army, No 30 Fucheng Rd, Beijing 100142, China
| | - Chao Zheng
- Orthopedic Department, Air Force General Hospital of Chinese People's Liberation Army, No 30 Fucheng Rd, Beijing 100142, China
| | - Yuming Cui
- Orthopedic Department, Air Force General Hospital of Chinese People's Liberation Army, No 30 Fucheng Rd, Beijing 100142, China
| | - Shucheng Rao
- Orthopedic Department, West China Hospital, Sichuan University, No. 37 Guo Xue Xiang, Chengdu, Sichuan 610041, China
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Relevant Anatomic and Morphological Measurements of the Rat Spine: Considerations for Rodent Models of Human Spine Trauma. Spine (Phila Pa 1976) 2015; 40:E1084-92. [PMID: 26731709 DOI: 10.1097/brs.0000000000001021] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Basic science study measuring anatomical features of the cervical and lumbar spine in rat with normalized comparison with the human. OBJECTIVE The goal of this study is to comprehensively compare the rat and human cervical and lumbar spines to investigate whether the rat is an appropriate model for spine biomechanics investigations. SUMMARY OF BACKGROUND DATA Animal models have been used for a long time to investigate the effects of trauma, degenerative changes, and mechanical loading on the structure and function of the spine. Comparative studies have reported some mechanical properties and/or anatomical dimensions of the spine to be similar between various species. However, those studies are largely limited to the lumbar spine, and a comprehensive comparison of the rat and human spines is lacking. METHODS Spines were harvested from male Holtzman rats (n = 5) and were scanned using micro- computed tomography and digitally rendered in 3 dimensions to quantify the spinal bony anatomy, including the lateral width and anteroposterior depth of the vertebra, vertebral body, and spinal canal, as well as the vertebral body and intervertebral disc heights. Normalized measurements of the vertebra, vertebral body, and spinal canal of the rat were computed and compared with corresponding measurements from the literature for the human in the cervical and lumbar spinal regions. RESULTS The vertebral dimensions of the rat spine vary more between spinal levels than in humans. Rat vertebrae are more slender than human vertebrae, but the width-to-depth axial aspect ratios are very similar in both species in both the cervical and lumbar regions, especially for the spinal canal. CONCLUSION The similar spinal morphology in the axial plane between rats and humans supports using the rat spine as an appropriate surrogate for modeling axial and shear loading of the human spine.
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Bigland MJ, Budgell BS, Bolton PS. The influence of cervical spinal cord compression and vertebral displacement on somatosympathetic reflexes in the rat. Spine J 2015; 15:1310-7. [PMID: 24176810 DOI: 10.1016/j.spinee.2013.08.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 06/30/2013] [Accepted: 08/20/2013] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT One theory within chiropractic proposes that vertebral subluxation in the upper cervical region induces spinal cord compression sufficient to alter spinal cord efferent output. We report on the feasibility of three different experimental approaches to test this theory. METHODS A high threshold electrical-evoked somatosympathetic reflex was recorded in adrenal or renal nerves of 10 anaesthetized adult male rats before and after (1) graded pressure was applied directly to the C1/C2 spinal cord segment in eight rats by the use of either direct compression or inflation of an extradural balloon and (2) displacement, less than a dislocation applied posterior to anterior, to the C2 vertebra in two rats. The latency and amplitude of the pre- and postintervention reflex responses were compared. RESULTS The reflex amplitude was not significantly changed by pressure (26 mmHg) from an extra-dural balloon or direct compression of the dura mater onto the dorsal spinal cord. Additional pressure, at least sufficient to occlude the dorsal vessels, induced a significant reduction in the amplitude of the reflex, and this reduction persisted for 20 minutes after removal of the pressure (Dunn's method for all pairwise multiple comparison Q stat=3.437; critical value for k=6 with α=0.05 is 2.936). Maximal vertebral (C2) displacement (4 mm), without dislocation did not induce significant changes compared with the control period. CONCLUSIONS Although this feasibility study suggests it is unlikely that upper cervical vertebral subluxation, displacement less than a dislocation, compromises the sympathetic outflow in the adrenal or renal nerves, further vertebral displacement studies are necessary to formally test this.
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Affiliation(s)
- Mark J Bigland
- School of Biomedical Sciences & Pharmacy, Faculty of Health and Medicine, University of Newcastle, University Drive, Callaghan, NSW 2308, Australia
| | - Brian S Budgell
- Canadian Memorial Chiropractic College, 6100 Leslie St, Toronto, ON M2H3J1, Canada
| | - Philip S Bolton
- School of Biomedical Sciences & Pharmacy, Faculty of Health and Medicine, University of Newcastle, University Drive, Callaghan, NSW 2308, Australia; Priority Research Centre for Translational Neuroscience and Mental Health, University of Newcastle, University Drive, Callaghan, NSW 2308, Australia.
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Griffin C, Choong WY, Teh W, Buxton AJ, Bolton PS. Head and cervical spine posture in behaving rats: implications for modeling human conditions involving the head and cervical spine. Anat Rec (Hoboken) 2014; 298:455-62. [PMID: 25219425 DOI: 10.1002/ar.23049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 07/17/2014] [Accepted: 08/04/2014] [Indexed: 01/08/2023]
Abstract
The aim of this study was to define the temporal and spatial (postural) characteristics of the head and cervical vertebral column (spine) of behaving rats in order to better understand their suitability as a model to study human conditions involving the head and neck. Time spent in each of four behavioral postures was determined from video tape recordings of rats (n = 10) in the absence and presence of an intruder rat. Plain film radiographic examination of a subset of these rats (n = 5) in each of these postures allowed measurement of head and cervical vertebral column positions adopted by the rats. When single they were quadruped or crouched most (∼80%) of the time and bipedal either supported or free standing for only ∼10% of the time. The introduction of an intruder significantly (P < 0.0001) reduced the proportion of time rats spent quadruped (median, from 71% to 47%) and bipedal free standing (median, from 2.9% to 0.4%). The cervical spine was orientated (median, 25-75 percentile) near vertical (18.8°, 4.2°-30.9°) when quadruped, crouched (15.4°, 7.6°-69.3°) and bipedal supported (10.5°, 4.8°-22.6°) but tended to be less vertical oriented when bipedal free standing (25.9°, 7.7°-39.3°). The range of head positions relative to the cervical spine was largest when crouched (73.4°) and smallest when erect free standing (17.7°). This study indicates that, like humans, rats have near vertical orientated cervical vertebral columns but, in contrast to humans, they displace their head in space by movements at both the cervico-thoracic junction and the cranio-cervical regions.
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Affiliation(s)
- C Griffin
- School of Biomedical Sciences & Pharmacy, Faculty of Health and Medicine, University of Newcastle, Callaghan NSW, Australia
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Laing AC, Brenneman EC, Yung A, liu J, Kozlowski P, Oxland T. The Effects of Age on the Morphometry of the Cervical Spinal Cord and Spinal Column in Adult Rats: An MRI-Based Study. Anat Rec (Hoboken) 2014; 297:1885-95. [PMID: 25044631 DOI: 10.1002/ar.22995] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 05/04/2014] [Accepted: 05/28/2014] [Indexed: 01/15/2023]
Affiliation(s)
- Andrew C. Laing
- Injury Biomechanics and Aging Laboratory, Department of Kinesiology; University of Waterloo, 200 University Ave West; Waterloo Ontario N2L 3G1 Canada
- International Collaboration on Repair Discoveries (ICORD); University of British Columbia; 818 West 10th Avenue Vancouver British Columbia V5Z 1M9 Canada
| | - Elora C. Brenneman
- Injury Biomechanics and Aging Laboratory, Department of Kinesiology; University of Waterloo, 200 University Ave West; Waterloo Ontario N2L 3G1 Canada
| | - Andrew Yung
- MRI Research Centre, University of British Columbia; 2221 Westbrook Mall Vancouver British Columbia V6T 2B5 Canada
| | - Jie liu
- International Collaboration on Repair Discoveries (ICORD); University of British Columbia; 818 West 10th Avenue Vancouver British Columbia V5Z 1M9 Canada
| | - Piotr Kozlowski
- International Collaboration on Repair Discoveries (ICORD); University of British Columbia; 818 West 10th Avenue Vancouver British Columbia V5Z 1M9 Canada
- MRI Research Centre, University of British Columbia; 2221 Westbrook Mall Vancouver British Columbia V6T 2B5 Canada
| | - Thomas Oxland
- International Collaboration on Repair Discoveries (ICORD); University of British Columbia; 818 West 10th Avenue Vancouver British Columbia V5Z 1M9 Canada
- Orthopaedics and Injury Biomechanics Group, Departments of Orthopaedics and Mechanical Engineering; University of British Columbia; 818 West 10th Avenue Vancouver British Columbia V5Z 1M9 Canada
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Is the vertebral canal prepared to host the aged spinal cord? A morphometric assessment. ZOOMORPHOLOGY 2014. [DOI: 10.1007/s00435-013-0215-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Morphometrical dimensions of the sheep thoracolumbar vertebrae as seen on digitised CT images. Lab Anim Res 2013; 29:138-47. [PMID: 24106508 PMCID: PMC3791347 DOI: 10.5625/lar.2013.29.3.138] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 06/13/2013] [Accepted: 07/05/2013] [Indexed: 11/21/2022] Open
Abstract
The sheep spine is widely used as a model for preclinical research in human medicine to test new spinal implants and surgical procedures. Therefore, precise morphometric data are needed. The present study aimed to provide computed tomographic (CT) morphometry of sheep thoracolumbar spine. Five adult normal Merino sheep were included in this study. Sheep were anaesthetised and positioned in sternal recumbency. Subsequently, transverse and sagittal images were obtained using a multi-detector-row helical CT scanner. Measurements of the vertebral bodies, pedicles, intervertebral disc and transverse processes were performed with dedicated software. Vertebral bodies and the spinal canal were wider than they were deep, most obviously in the lumbar vertebrae. The intervertebral discs were as much as 57.4% thicker in the lumbar than in the thoracic spine. The pedicles were higher and longer than they were wide over the entire thoracolumbar spine. In conclusion, the generated data can serve as a CT reference for the ovine thoracolumbar spine and may be helpful in using sheep spine as a model for human spinal research.
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Lee J, Satkunendrarajah K, Fehlings MG. Development and characterization of a novel rat model of cervical spondylotic myelopathy: the impact of chronic cord compression on clinical, neuroanatomical, and neurophysiological outcomes. J Neurotrauma 2011; 29:1012-27. [PMID: 21561323 DOI: 10.1089/neu.2010.1709] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord impairment worldwide and is a risk factor for traumatic central cord syndrome. Despite advances in surgery, there are no effective neuroprotective treatments for CSM, which reflects a limited understanding of its pathophysiology. In order to develop therapeutic strategies, we have developed a novel rat model of chronic progressive cervical spinal cord compression that mimics CSM. A titanium-screw-based chronic compression device (CCD) was designed to achieve progressive cord compression at the C6 level. The CCD was fixed to the C2 and T2 spinous processes and a threaded screw was turned to induce compression. Sprague-Dawley rats (n=75) were divided into three groups: (1) sham (no compression, n=6), (2) mild compression (1.4 mm stenosis, n=27), and (3) severe compression (2.6 mm stenosis, n=42). Compression was evaluated using micro-computed tomography (micro-CT). The area of spared white matter, extent of cord flattening ratio, and loss of neurons were assessed. Functional deficits were characterized using sensory-evoked potential (SEP) recordings, and with neurobehavioral tests: the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale, inclined plane, paw grip strength, and assessment of mechanical and thermal allodynia. Micro-CT confirmed progressive canal stenosis. The loss of intact white matter and cord flattening were significantly greater in rats with severe cord compression, and the number of neurons was reduced at the epicenter of cord compression. With chronic cord compression there was a significant decline in locomotor function, forelimb function, trunk stability/coordination, an increase in mechanical allodynia, and impaired axonal conduction. The CCD model results in chronic and precise cervical cord compression. The compression is associated with mechanical allodynia and measurable neurobehavioral, neurophysiological, and neuropathological deficits. We anticipate that the CCD model will enable the investigation of translationally-relevant therapeutic strategies for CSM.
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Affiliation(s)
- JangBo Lee
- Department of Genetics and Development, Toronto Western Research Institute, Spinal Program, Krembil Neuroscience Center, University Health Network, Toronto Ontario, Canada
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Laing AC, Cox R, Tetzlaff W, Oxland T. Effects of advanced age on the morphometry and degenerative state of the cervical spine in a rat model. Anat Rec (Hoboken) 2011; 294:1326-36. [PMID: 21714115 DOI: 10.1002/ar.21436] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 10/31/2010] [Accepted: 03/26/2011] [Indexed: 11/08/2022]
Abstract
Aging causes changes in the geometry of the human cervical spine that may influence the tissue response to applied loads. Rat models are often used to study spinal cord injuries (SCI) and have the potential to enhance our understanding of the effect of age on SCI. The goal of this study was to characterize the morphometry and degenerative state of the cervical spine in Fisher 344 rats, and to determine the influence of age on these variables. Fifteen rats were split into three age groups: young adult (3 months of age), aged (12-18 months) and geriatric (30 months). Following tissue harvest we used a μCT scanner to image the cervical and upper thoracic spine from each specimen. Analysis software was used to measure variables including canal pinch diameter (the most rostral point on the dorsal aspect of a vertebral body to the most caudal aspect of the lamina on the immediately rostral vertebra), vertebral canal depth, width, and area, vertebral body height, depth, width, and area, and intervertebral disc thickness. Orthopaedic surgeons used midsagittal images to rate the degenerative state of the intervertebral discs. For all measures except disc thickness there was a significant increase (mean (SD) = 15.0 (9.7)%) for the aged compared to young specimens (P < 0.05). There were significant differences between the aged and geriatric specimens for only vertebral body depth (P = 0.016) and area (P = 0.020). Intervertebral disc degeneration was significantly greater on the ventral aspect of the spinal column (P < 0.001), with a trend toward increased degeneration in the geriatric specimens (P = 0.069). The results suggest that age-related morphometric differences may need to be accounted for in experimental aging models of SCI in rats.
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Affiliation(s)
- Andrew C Laing
- Injury Biomechanics and Aging Laboratory, Department of Kinesiology, University of Waterloo, Ontario, Canada.
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Seifert JL, Bell JE, Elmer BB, Sucato DJ, Romero MI. Characterization of a novel bidirectional distraction spinal cord injury animal model. J Neurosci Methods 2011; 197:97-103. [PMID: 21334381 DOI: 10.1016/j.jneumeth.2011.02.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 01/17/2011] [Accepted: 02/06/2011] [Indexed: 11/26/2022]
Abstract
Scoliosis corrective surgery requires the application of significant multidirectional stress forces, including distraction, for correction of the curved spine deformity and the application of fixation rods. If excessive, spine distraction may result in the development of new neurological deficits, some as severe as permanent paralysis. Current animal models of spinal cord injury, however, are limited to contusion, transection, or unidirectional distraction injuries, which fail to replicate the multidirectional forces that occur during spine corrective surgery. To address such limitation, we designed a novel device that relies on intervertebral grip fixation and linear actuators to induce controllable bidirectional distraction injuries to the spine. The device was tested in three (i.e., 3, 5, and 7 mm) distention paradigms of the rat T9-T11 vertebra, and the resulting injuries were evaluated through electrophysiological, behavioral, and histological analysis. As expected, 3mm bilateral spine distractions showed no neurological deficit. In contrast, those with 5 and 7 mm showed partial and complete paralysis, respectively. The relationship between the severity of the spine distraction and injury to the spinal cord tissue was determined using glial fibrillary acidic protein immunocytochemistry for visualization of reactive astrocytes and labeling of ED1-positive activated macrophages/microglia. Our results demonstrate that this device can produce bidirectional spine distraction injuries with high precision and control and, thus, may be valuable in contributing to the testing of neuroprotective strategies aimed at preventing unintended new neurological damage during corrective spine surgery.
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Affiliation(s)
- J L Seifert
- Regenerative Neurobiology Laboratory, Joint Program of Bioengineering, University of Texas at Arlington, 701 South Nedderman Drive, Arlington, TX 76019, USA
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Budgell BS, Bolton PS. Cerebrospinal Fluid Pressure Response to Upper Cervical Vertebral Motion and Displacement in the Anesthetized Rat. J Manipulative Physiol Ther 2010; 33:355-61. [DOI: 10.1016/j.jmpt.2010.05.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Revised: 03/26/2010] [Accepted: 04/06/2010] [Indexed: 11/27/2022]
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Fontana PA, Barbeito CG, Goya RG, Gimeno EJ, Portiansky EL. Impact of very old age on the expression of cervical spinal cord cell markers in rats. J Chem Neuroanat 2008; 37:98-104. [PMID: 19059476 DOI: 10.1016/j.jchemneu.2008.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Revised: 10/31/2008] [Accepted: 11/01/2008] [Indexed: 01/09/2023]
Abstract
Aging is a process associated with both anatomical changes and loss of expression of some cell markers. Intermediate filaments are known to impart mechanical stability to cells and tissues. Some of them are present in different cell populations of the central nervous system. In order to explore the impact of extreme age we immunohistochemically characterized the changes in intermediate filaments and other cellular markers present in cells populating the gray matter cervical spinal cord of very old rats (28 months) taking young (5 months) counterparts as a reference. The spinal cord weight of the senile animals (12.6+/-1.1 g) was significantly higher (P<0.001) than that of the young animals (8.4+/-1.1 g). Spinal cord length also increased significantly (P<0.05) with age (7.9+/-0.3 cm vs. 8.28+/-0.1 cm for young and senile, respectively). An increase in both neurofilament staining area and density was observed in senile rats in comparison to young animals. A significant (P<0.05) age-related increment in the mean area of the cervical segments was observed. Vimentin expression in the ependymal zone decreased in area and intensity during aging. Our data show that there are some significant changes in the morphological and histochemical patterns of the cervical spinal cord in senile rats. However, they do not necessarily represent a pathologic situation and may rather reflect plastic reorganization.
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Affiliation(s)
- Paula Andrea Fontana
- Institute of Pathology, School of Veterinary Sciences, National University of La Plata, La Plata 1900, Argentina
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