OBJECTIVE: Sequelae of behavioral impairments associated with human traumatic brain injury (TBI) include neurobehavioral problems. We compared exploratory, cognitive, and depressive-like behaviors in pediatric and adult male mice exposed to controlled cortical impact (CCI).METHODS: Pediatric (21 to 25 days old) and adult (8 to 12 weeks old) male C57Bl/6 mice underwent CCI at a 2-mm depth of deflection. Hematoxylin and eosin staining was performed 3 to 7 days after recovery from CCI, and injury volume was analyzed using ImageJ. Neurobehavioral characterization after CCI was performed using the Barnes maze test (BMT), passive avoidance test, open-field test, light/dark test, tail suspension test, and rotarod test. Acutely and subacutely (3 and 7 days after CCI, respectively), CCI mice showed graded injury compared to sham mice for all analyzed deflection depths.RESULTS: Time-dependent differences in injury volume were noted between 3 and 7 days following 2-mm TBI in adult mice. In the BMT, 2-mm TBI adults showed spatial memory deficits compared to sham adults (P < 0.05). However, no difference in spatial learning and memory was found between sham and 2-mm CCI groups among pediatric mice. The open-field test, light/dark test, and tail suspension test did not reveal differences in anxiety-like behaviors in both age groups.CONCLUSION: Our findings revealed a graded injury response in both age groups. The BMT was an efficient cognitive test for assessing spatial/non-spatial learning following CCI in adult mice; however, spatial learning impairments in pediatric mice could not be assessed.
Adult ; Animals ; Brain Injuries ; Eosine Yellowish-(YS) ; Hematoxylin ; Hindlimb Suspension ; Humans ; Learning ; Male ; Memory ; Mice ; Rotarod Performance Test ; Spatial Learning ; Spatial Memory

Remyelination via the transplantation of oligodendrocyte precursor cells (OPCs) has been considered as a strategy to improve the locomotor deficits caused by traumatic spinal cord injury (SCI). To date, enormous efforts have been made to derive OPCs from human pluripotent stem cells (hPSCs), and significant progress in the transplantation of such cells in SCI animal models has been reported. The current methods generally require a long period of time (>2 months) to obtain transplantable OPCs, which hampers their clinical utility for patients with SCI. Here we demonstrate a rapid and efficient method to differentiate hPSCs into neural progenitors that retain the features of OPCs (referred to as OPC-like cells). We used cell sorting to select A2B5-positive cells from hPSC-derived neural rosettes and cultured the selected cells in the presence of signaling cues, including sonic hedgehog, PDGF and insulin-like growth factor-1. This method robustly generated neural cells positive for platelet-derived growth factor receptor-α (PDGFRα) and NG2 (~90%) after 4 weeks of differentiation. Behavioral tests revealed that the transplantation of the OPC-like cells into the spinal cords of rats with contusive SCI at the thoracic level significantly improved hindlimb locomotor function. Electrophysiological assessment revealed enhanced neural conduction through the injury site. Histological examination showed increased numbers of axon with myelination at the injury site and graft-derived myelin formation with no evidence of tumor formation. Our method provides a cell source from hPSCs that has the potential to recover motor function following SCI.
Animals ; Axons ; Behavior Rating Scale ; Cues ; Hedgehogs ; Hindlimb ; Humans* ; Methods ; Models, Animal ; Myelin Sheath ; Neural Conduction ; Oligodendroglia ; Platelet-Derived Growth Factor ; Pluripotent Stem Cells* ; Rats ; Spinal Cord Injuries* ; Spinal Cord*

PURPOSE: Traumatic brain injury (TBI) is a significant cause of morbidity and mortality worldwide. Severity of the initial insult is one of the most significant factors affecting outcome following TBI. In order to investigate the mechanisms of cellular injury and develop novel therapeutic strategies for TBI, we designed a standardized animal TBI model and evaluated histological and functional outcomes according to the degree of impact severity. METHODS: Male adult C57Bl/6 mice underwent controlled cortical impact (CCI) at varying depths of deflection (1.0-2.0 mm). We performed hematoxylin and eosin staining at 7 days after recovery from TBI. Neurobehavioral characterization after TBI was analyzed by the Barnes maze test, passive avoidance test, open field test, rotarod test, tail suspension test, and light/dark test. RESULTS: We observed a graded injury response according to the degree of deflection depths tested (diameter, 3 mm; velocity, 3 m/s; and duration, 500 ms) compared to sham controls. In the Barnes maze test, the severe TBI (2 mm depth) group showed reduced spatial memory as compared with the sham and mild TBI (1 mm depth) groups at 7 days after TBI. There was a significant difference in the results of the open field test and light/dark test among the three groups. CONCLUSION: Our findings demonstrate that the graded injury responses following TBI resulted in differential histopathological and behavioral outcomes in a mouse experimental CCI model. Thus, a model of CCI with histologic/behavioral outcome analysis may offer a reliable and convenient design for preclinical TBI research involving mice.
Adult* ; Animals ; Brain Injuries* ; Eosine Yellowish-(YS) ; Hematoxylin ; Hindlimb Suspension ; Humans ; Male ; Mice* ; Mortality ; Neurobehavioral Manifestations ; Rotarod Performance Test ; Spatial Memory

Skeletal muscle possesses plasticity and adaptability to external and internal physiological changes. Due to these characteristics, skeletal muscle shows dramatic changes depending on its response to stimuli such as physical activity, nutritional changes, disease status, and environmental changes. Modulation of the rate of protein synthesis/degradation plays an important role in atrophic responses. The purpose of this review is to describe different features of skeletal muscle adaptation with various models of deceased use. In this review, four models were addressed: immobilization, spinal cord transection, hindlimb unloading, and aging. Immobilization is a form of decreased use in which skeletal muscle shows electrical activity, tension development, and motion. These results differ by muscle group. Spinal cord transection was selected to simulate spinal cord injury. Similar to the immobilization model, dramatic atrophy occurs in addition to fiber type conversion in this model. Despite the fact that electromyography shows unremarkable changes in muscle after hindlimb unloading, decreased muscle mass and contractile force are observed. Lastly, aging significantly decreases the numbers of muscle fibers and motor units. Skeletal muscle responses to decreased use include decreased strength, decreased fiber numbers, and fiber type transformation. These four models demonstrated different changes in the skeletal muscle. This review elucidates the different skeletal muscle adaptations in these four decreased use animal models and encourages further studies.
Aging ; Atrophy ; Electromyography ; Hindlimb Suspension ; Immobilization ; Models, Animal ; Motor Activity ; Muscle, Skeletal* ; Plastics ; Rodentia* ; Spinal Cord Injuries

OBJECTIVETo investigate the effect of suppressing apoptosis signal regulating kinase 1 (ASK1) on glial fibrillary acidic protein (GFAP) and vimentin expressions at the injury site and on hindlimb mobility in rats after spinal cord injury (SCI).

METHODSThe rat models of SCI were established by extradural compression of the spinal cord using an aneurysm clip. The injured rats were treated with normal saline (model group), ASK1 specific inhibitor thioredoxin (Trx group), or ASK1 monoclonal antibody (Anti-ASK1 group), and the rats receiving a sham operation underwent laminectomy without SCI. The expression of GFAP and vimentin were detected by Western blotting and immunofluorescence assay at 1, 7, 14 and 28 days after SCI. The motion function of the hindlimbs of the injured rats was assessed with Basso Beattie Bresnahan (BBB) scores, and somatosensory-evoked potentials (SEP) and motor-evoked potentials (MEP) were determined to examine the electrophysiological changes.

RESULTSAt 1 day after SCI, the expressions of GFAP and vimentin showed no significant differences among the groups; at 7, 14 and 28 days after SCI, GFAP and vimentin expressions significantly increased in Trx and Anti-ASK1 groups compared with those in the model group (P<0.01). The BBB scores showed no significant differences among the groups at 1, 7 and 14 days after SCI, while at 28 days, the BBB scores in Trx and Anti-ASK1 groups were significantly higher than those in the model group (P<0.01). At 28 days after SCI, the latent period of SEP and MEP decreased and the amplitude increased significantly in Trx and Anti-ASK1 groups compared with that in the model group (P<0.01).

CONCLUSIONBlocking ASK1 can inhibit the expression of GFAP and vimentin in glial scars and improve the outcomes of hindlimb mobility in rats after SCI.

Animals ; Disease Models, Animal ; Evoked Potentials, Motor ; Evoked Potentials, Somatosensory ; Glial Fibrillary Acidic Protein ; metabolism ; Hindlimb ; physiopathology ; MAP Kinase Kinase Kinase 5 ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Spinal Cord Injuries ; metabolism ; Vimentin ; metabolism

OBJECTIVE: To investigate the process of apoptosis in lungs and liver induced by crushing hindlimbs of rat, and study the mechanism of crush injury. METHODS: The rat experimental model of hindlimbs crush injury was established. The cell apoptosis in lungs and liver was detected by TUNEL assay, and the expression of Bax, Bcl-2 and caspase-3 apoptin was examined by immunohistochemistry. RESULTS: Compared with the control group, the partial muscle injury of rat's hindlimbs was more serious with more apoptosis observed in lungs and liver (P < 0.05). The expression of Bax was up-regulated and Bcl-2 was down-regulated, whereas caspase-3 expression was activated (P < 0.05). CONCLUSION The cell apoptosis has increased significantly in lungs and liver after crush injury of hindlimbs in rat. The correlation factor released during tissue injury may mediate apoptosis process.
Animals ; Apoptosis/physiology* ; Caspase 3/metabolism* ; Genes, bcl-2 ; Hindlimb/injuries* ; Immunohistochemistry ; Liver/physiopathology* ; Lung/physiopathology* ; Rats ; Up-Regulation ; bcl-2-Associated X Protein

OBJECTIVE: This study describes a method for inducing spinal cord injuries in dogs by using balloon catheters via laminectomy and the subsequent changes in the electrophysiological response. METHODS: Female Beagle (Orient Bio, Seongnam, Korea) dogs weighing 10 kg at the time of injury were used. Under inhalation anesthesia, a posterior midline approach laminectomy was performed. A silicone balloon catheter (size 6 Fr; Sewoon Medical, Cheonan, Korea) was then inserted into the vertebral canal at the center of T10. The balloon was inflated to the maximum volume for 1, 2, or 3 days. Open field testing was performed for evaluating motor functions of the hindlimbs. Motor evoked potentials (MEPs) induced by electrical and magnetic stimulation were recorded before and after spinal cord injury. RESULTS: Open field testing yielded locomotor scores of 0 or 1 for dogs subjected to compression for 3 days. These dogs showed no obvious improvement throughout the observation period, and the tonus of their hindlimbs was flaccid. In contrast, motor functions of dogs that had experienced compression for 1 or 2 days were variable, and all dogs showed spastic tonus in their hindlimbs. In dogs subjected to after compression for 3 days, electrically stimulated MEPs for the hindlimbs showed a significant amplitude reduction. Further, hindlimb movements were not evoked by magnetic stimulation of the cervical spine and vertex area. CONCLUSION: Compression for 3 days with a balloon catheter is a safe, reproducible, and reliable method for evaluating electrophysiological changes in a dog model of complete spinal cord injury.
Anesthesia, Inhalation ; Animals ; Catheters ; Chungcheongnam-do ; Dogs* ; Evoked Potentials, Motor ; Female ; Gyeonggi-do ; Hindlimb ; Humans ; Laminectomy ; Muscle Spasticity ; Silicones ; Spinal Cord Injuries* ; Spine

OBJECTIVE: To observe the effect of curing-injury cataplasma on the expression of aquaporin protein 3 (AQP-3) in skeletal muscle of rat model with acute injury in soft tissues. METHODS: A total of 54 SD rats were randomly divided into 3 groups, and by using 10% sodium sulfide the depilating treatment was made in the thigh lateral of each left hind leg 1 day before modeling. The depilatory area in the control group was merely marked with striking range, not attacked for modeling. In the depilatory area of the modeling group, the blowing apparatus was used to attack the marked range to establish the model of soft tissue swelling with acute injury, to which none medication was given. In the drug treatment group, immediately after establishing the model of soft tissue swelling with acute injury, curing-injury cataplasma was scattered on the stricken area, and fixed with bandage. After the modeling, the rats were killed at 1 h, 6 h, 1 d, 3 d, 5 d, and 7 d, 3 rats in each group at each time point. In the marked area some tissue was taken, and the dry/wet proportion method was used to detect the water content in the skeletal muscle. Western blot and qPCR method were used for the AQP-3 protein and the level of gene expression. RESULTS: At the six time points, for the modeling and drug treatment groups, the water content of skeletal muscle was higher than that of the control group (P<0.05). At 3 d, 5 d and 7 d, the water content in the drug treatment group was lower than that of the modeling group (P<0.01); for the modeling and drug treatment groups, AQP-3 protein and the level of gene expression were higher than those of the control group. There was significant difference between the drug treatment group and the modeling group (P<0.01). CONCLUSION Curing-injury cataplasma can relieve soft tissue swelling with acute injury, and accelerate the repair process after the injury.
Animals ; Aquaporin 3 ; metabolism ; Drugs, Chinese Herbal ; therapeutic use ; Hindlimb ; injuries ; Male ; Muscle, Skeletal ; metabolism ; Rats ; Rats, Sprague-Dawley ; Soft Tissue Injuries ; drug therapy ; metabolism

As one of trials on neuroprotection after spinal cord injury, we used pregabalin. After spinal cord injury (SCI) in rats using contusion model, we observed the effect of pregabalin compared to that of the control and the methylprednisolone treated rats. We observed locomotor improvement of paralyzed hindlimb and body weight changes for clinical evaluation and caspase-3, bcl-2, and p38 MAPK expressions using western blotting. On histopathological analysis, we also evaluated reactive proliferation of glial cells. We were able to observe pregabalin's effectiveness as a neuroprotector after SCI in terms of the clinical indicators and the laboratory findings. The caspase-3 and phosphorylated p38 MAPK expressions of the pregabalin group were lower than those of the control group (statistically significant with caspase-3). Bcl-2 showed no significant difference between the control group and the treated groups. On the histopathological analysis, pregabalin treatment demonstrated less proliferation of the microglia and astrocytes. With this animal study, we were able to demonstrate reproducible results of pregabalin's neuroprotection effect. Diminished production of caspase-3 and phosphorylated p38 MAPK and as well as decreased proliferation of astrocytes were seen with the administration of pregabalin. This influence on spinal cord injury might be a possible approach for achieving neuroprotection following central nervous system trauma including spinal cord injury.
Animals ; Apoptosis/drug effects ; Astrocytes/drug effects/pathology ; Blotting, Western ; Body Weight/drug effects ; Caspase 3/genetics ; Cell Proliferation ; Fluorescent Antibody Technique ; Gene Expression ; Hindlimb/drug effects/pathology/physiopathology ; Inflammation ; Male ; Methylprednisolone/therapeutic use ; Microglia/drug effects/pathology ; Motor Activity/drug effects ; Neuroglia/*drug effects/pathology ; Neuroprotective Agents/*therapeutic use ; Paralysis/drug therapy ; Proto-Oncogene Proteins c-bcl-2/genetics ; Rats ; Rats, Sprague-Dawley ; Spinal Cord Injuries/*drug therapy/pathology ; gamma-Aminobutyric Acid/*analogs & derivatives/therapeutic use ; p38 Mitogen-Activated Protein Kinases/genetics

PURPOSE: The purpose of this study was to examine effects of nitric oxide synthase (NOS) inhibitor on muscle weight and myofibrillar protein content of affected and unaffected hindlimb muscles in rats with neuropathic pain induced by unilateral peripheral nerve injury. METHODS: Neuropathic pain was induced by ligation and cutting of the left L5 spinal nerve. Adult male Sprague-Dawley rats were randomly assigned to one of two groups: The NOSI group (n=19) had NOS inhibitor (L-NAME) injections daily for 14 days, and the Vehicle group (n=20) had vehicle injections daily for 14 days. Withdrawal threshold, body weight, food intake and activity were measured every day. At 15 days all rats were anesthetized and soleus, plantaris and gastrocnemius muscles were dissected from hindlimbs. Muscle weight and myofibrillar protein content of the dissected muscles were determined. RESULTS: The NOSI group showed significant increases as compared to the Vehicle group for body weight at 15 days, muscle weight and myofibrillar protein content of the unaffected soleus and gastrocnemius. The NOSI group demonstrated a higher pain threshold than the vehicle group. CONCLUSION: NOSI for 14 days attenuates unaffected soleus and gastrocnemius muscle atrophy in neuropathic pain model.
Animals ; Body Weight/drug effects ; Disease Models, Animal ; Eating/drug effects ; Enzyme Inhibitors/*administration & dosage/pharmacology ; *Hindlimb ; Male ; Muscle Fibers, Skeletal/*drug effects/metabolism ; Muscle Proteins/metabolism ; Muscular Atrophy/drug therapy ; NG-Nitroarginine Methyl Ester/*administration & dosage/pharmacology ; Neuralgia/*etiology ; Nitric Oxide Synthase/*antagonists & inhibitors/metabolism ; *Peripheral Nerve Injuries ; Rats ; Rats, Sprague-Dawley