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Neckel ND, Dai H. Viscous field training induces after effects but hinders recovery of overground locomotion following spinal cord injury in rats. Behav Brain Res 2021; 412:113415. [PMID: 34153426 PMCID: PMC8282748 DOI: 10.1016/j.bbr.2021.113415] [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: 04/11/2021] [Revised: 05/23/2021] [Accepted: 06/09/2021] [Indexed: 11/17/2022]
Abstract
Robotic-assisted gait training was able to improve the unassisted overground locomotion of rats following a cervical spinal cord injury. Specifically, four weeks of daily step training in the Robomedica Rodent Robotic Motor Performance System, where the device actively guided the hindlimbs through a pre-injury stepping pattern while the rats walked over a moving treadmill belt in a quadrupedal posture, was able to improve unassisted overground locomotion as measured by the CatWalk gait analysis device. Unfortunately the improvements were minimal. In fact, control animals that received only body weight supported treadmill training and no active robotic forces showed an even greater restoration of unassisted overground locomotion. This led us to further investigate the effects of the specific forces used in rehabilitative training. The robotic training device was modified to apply assistive (negative viscosity) or resistive (viscous) fields in lieu of the standard active guidance. Within the device, daily training with a viscous field resulted in small, constrained steps that were similar to pre-injury steps. However, when the robot was off for weekly assessments, the steps opened up and deviated away from pre-injury levels. Training in a negative viscosity field produced the opposite effect; large open steps that were unlike pre-injury during daily training, and constrained steps that were more like pre-injury during weekly assessment. These training induced after-effects washed out 2 weeks after the cessation of training. Additionally, these distinct after effects seen in the training device did not translate to distinct differences in the recovery of unassisted overground locomotion, with the body weight supported treadmill training controls showing the greatest recovery of overground locomotion. Still, the fact that different applied forces can induce different after effects has interesting implications for rehabilitative training - is it better to have healthy looking steps during training only to induce abnormal after effects, or have abnormal performance during training but with desirable after effects? The data presented here is the first step in addressing this question.
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Affiliation(s)
- Nathan D Neckel
- Department of Neuroscience, Georgetown University, United States; Department of Rehabilitation Medicine, Georgetown University, United States.
| | - Haining Dai
- Department of Neuroscience, Georgetown University, United States
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Zhou XH, Li WT, Zhao BL, Bao ZR, Liu CH, Wu SQ, Xue HX, Liu YB, Han CH, Wang J, An LB. Design and Evaluation of a Novel Laminectomy Auxiliary Device Based on Rats. IEEE Trans Neural Syst Rehabil Eng 2020; 28:621-628. [DOI: 10.1109/tnsre.2020.2968610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Lin Y, Li C, Li J, Deng R, Huang J, Zhang Q, Lyu J, Hao N, Zhong Z. NEP 1-40-modified human serum albumin nanoparticles enhance the therapeutic effect of methylprednisolone against spinal cord injury. J Nanobiotechnology 2019; 17:12. [PMID: 30670038 PMCID: PMC6341626 DOI: 10.1186/s12951-019-0449-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Accepted: 01/09/2019] [Indexed: 01/16/2023] Open
Abstract
Background Frequent injection of high-dose methylprednisolone (MP) is used to treat spinal cord injury (SCI), but free MP is associated with various side effects and its water solubility is low, limiting potential dosing regimes and administration routes. Albumin-based nanoparticles, which can encapsulate therapeutic drugs and release cargo in a controlled pattern, show high biocompatibility and low toxicity. The Nogo protein, expressed on the surface of oligodendrocytes, can inhibit axonal growth by binding with the axonal Nogo receptor (NgR). Peptide NEP1-40, an NgR antagonist, can bind specifically to Nogo, significantly improving functional recovery and axon growth in the corticospinal tract. Therefore, we hypothesized that delivering MP within nanoparticles decorated with NEP1-40 could avoid the disadvantages of free MP and enhance its therapeutic efficacy against SCI. Results We used human serum albumin to prepare MP-loaded NPs (MP-NPs), to whose surface we conjugated NEP1-40 to form NEP1-40-MP-NPs. Transmission electron microscopy indicated successful formation of nanoparticles. NEP1-40-MP-NPs were taken up significantly better than MP-NPs by the Nogo-positive cell line RSC-96 and were associated with significantly higher Basso–Beattie–Bresnahan locomotor scores in rats recovering from SCI. Micro-computed tomography assay showed that NEP1-40-MP-NPs mitigated SCI-associated loss of bone mineral density and accelerated spinal cord repair. Conclusions NEP1-40-MP-NPs can enhance the therapeutic effects of MP against SCI. This novel platform may also be useful for delivering other types of drugs. ![]() Electronic supplementary material The online version of this article (10.1186/s12951-019-0449-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yan Lin
- Department of Pharmaceutical Sciences, School of Pharmacy, Southwest Medical University, Luzhou, 646000, China
| | - Chunhong Li
- Department of Pharmaceutical Sciences, School of Pharmacy, Southwest Medical University, Luzhou, 646000, China
| | - Jian Li
- Department of Pharmaceutical Sciences, School of Pharmacy, Southwest Medical University, Luzhou, 646000, China
| | - Ruolan Deng
- Department of Pharmaceutical Sciences, School of Pharmacy, Southwest Medical University, Luzhou, 646000, China
| | - Juan Huang
- Luzhou TCM Hospital, Luzhou, 646000, China
| | | | - Jiayao Lyu
- Department of Pharmaceutical Sciences, School of Pharmacy, Southwest Medical University, Luzhou, 646000, China
| | - Na Hao
- Department of Pharmaceutical Sciences, School of Pharmacy, Southwest Medical University, Luzhou, 646000, China.
| | - Zhirong Zhong
- Department of Pharmaceutical Sciences, School of Pharmacy, Southwest Medical University, Luzhou, 646000, China. .,Key Laboratory of Drug Targeting and Drug Delivery System, Ministry of Education (Sichuan University), Chengdu, 610000, China. .,Key Laboratory of Medical Electrophysiology, Ministry of Education, Institute of Cardiovascular Research of Southwest Medical University, Luzhou, 646000, China.
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