Passive activity enhances residual control ability in patients with complete spinal cord injury

Patients with complete spinal cord injury retain the potential for volitional muscle activity in muscles located below the spinal injury level.However,because of prolonged inactivity,initial attempts to activate these muscles may not effectively engage any of the remaining neurons in the descending pathway.A previous study unexpectedly found that a brief clinical round of passive activity significantly increased volitional muscle activation,as measured by surface electromyography.In this study,we further explored the effect of passive activity on surface electromyographic signals during volitional control tasks among individuals with complete spinal cord injury.Eleven patients with chronic complete thoracic spinal cord injury were recruited.Surface electromyography data from eight major leg muscles were acquired and compared before and after the passive activity protocol.The results indicated that the passive activity led to an increased number of activated volitional muscles and an increased frequency of activation.Although the cumulative root mean square of surface electromyography amplitude for volitional control of movement showed a slight increase after passive activity,the difference was not statistically significant.These findings suggest that brief passive activity may enhance the ability to initiate volitional muscle activity during surface electromyography tasks and underscore the potential of passive activity for improving residual motor control among patients with motor complete spinal cord injury.

Activation of adult endogenous neurogenesis by a hyaluronic acid collagen gel containing basic fibroblast growth factor promotes remodeling and functional recovery of the injured cerebral cortex

The presence of endogenous neural stem/progenitor cells in the adult mammalian brain suggests that the central nervous system can be repaired and regenerated after injury.However,whether it is possible to stimulate neurogenesis and reconstruct cortical layers II to VI in non-neurogenic regions,such as the cortex,remains unknown.In this study,we implanted a hyaluronic acid collagen gel loaded with basic fibroblast growth factor into the motor cortex immediately following traumatic injury.Our findings reveal that this gel effectively stimulated the proliferation and migration of endogenous neural stem/progenitor cells,as well as their differentiation into mature and functionally integrated neurons.Importantly,these new neurons reconstructed the architecture of cortical layers II to VI,integrated into the existing neural circuitry,and ultimately led to improved brain function.These findings offer novel insight into potential clinical treatments for traumatic cerebral cortex injuries.

Exercise-with-melatonin therapy improves sleep disorder and motor dysfunction in a rat model of ischemic stroke

Exercise-with-melatonin therapy has complementary and synergistic effects on spinal cord injury and Alzheimer's disease,but its effect on stroke is still poorly understood.In this study,we established a rat model of ischemic stroke by occluding the middle cerebral artery for 60 minutes.We treated the rats with exercise and melatonin therapy for 7 consecutive days.Results showed that exercise-with-melatonin therapy significantly prolonged sleep duration in the model rats,increased delta power values,and regularized delta power rhythm.Additionally,exercise-with-melatonin therapy improved coordination,endurance,and grip strength,as well as learning and memory abilities.At the same time,it led to higher hippocampal CA1 neuron activity and postsynaptic density thickness and lower expression of glutamate receptor 2 than did exercise or melatonin therapy alone.These findings suggest that exercise-withmelatonin therapy can alleviate sleep disorder and motor dysfunction by increasing glutamate receptor 2 protein expression and regulating hippocampal CA1 synaptic plasticity.

Development of diabetic complications and influencing factors among 32653 type 2 diabetes patients:retrospective cohort study using a multi-state Markov

Background:Patients with type 2 diabetes are at high risk for developing multiple chronic complications.However,there is a lack of studies of the cumulative number of diabetic complications in China.Methods:A retrospective cohort study was performed from 2009 to 2021.Type 2 diabetes patients who were first diagnosed after the age of 35 years between January 1,2009,and December 31,2017,were included.Five states were defined according to the number of chronic complications:no(S0),one(S1),two(S2),three(S3),and four or more complications(S4).A multi-state Markov model was constructed to estimate transition probability,transition intensity,mean sojourn time,and the possible factors for each state.Results:The study included 32653 type 2 diabetes patients(mean age,59.59 years;15929(48.8%)male),and mean follow-up time of 7.75 years.In all,4375 transitions were observed.The 12-year transition probability of from state S0 to S1 was the lowest at 16.4%,while that from S2 to S3 was the highest,at 45.6%.Higher fasting blood glucose,lower high-density lipoprotein cholesterol,higher total cholesterol,and an unhealthy diet were associated with higher risk of progression from S0 to S1.Being female,less than 60 years old,weekly physical activity,and vegetarian diet decreased this risk.Being female and less than 60 years old reduced the likelihood of transition from S1 to S2,whereas lower high-density lipoprotein cholesterol increased this likelihood.Conclusions:Following the occurrence of two complications in type 2 diabetes patients,the risk for accumulating a third complication within a short time is significantly increased.It is important to take advantage of the stable window period when patients have fewer than two complications,strengthen the monitoring of blood glucose and blood lipids,and encourage patients to maintain good living habits to prevent further deterioration.

Pathological significance of tRNA-derived small RNAs in neurological disorders

Non-coding RNAs(ncRNAs) are a type of RNA that is not translated into proteins. Transfer RNAs(tRNAs), a type of ncRNA, are the second most abundant type of RNA in cells. Recent studies have shown that tRNAs can be cleaved into a heterogeneous population of ncRNAs with lengths of 18–40 nucleotides, known as tRNA-derived small RNAs(tsRNAs). There are two main types of tsRNA, based on their length and the number of cleavage sites that they contain: tRNA-derived fragments and tRNA-derived stress-induced RNAs. These RNA species were first considered to be byproducts of tRNA random cleavage. However, mounting evidence has demonstrated their critical functional roles as regulatory factors in the pathophysiological processes of various diseases, including neurological diseases. However, the underlying mechanisms by which tsRNAs affect specific cellular processes are largely unknown. Therefore, this study comprehensively summarizes the following points:(1) The biogenetics of tsRNA, including their discovery, classification, formation, and the roles of key enzymes.(2) The main biological functions of tsRNA, including its miRNA-like roles in gene expression regulation, protein translation regulation, regulation of various cellular activities, immune mediation, and response to stress.(3) The potential mechanisms of pathophysiological changes in neurological diseases that are regulated by tsRNA, including neurodegeneration and neurotrauma.(4) The identification of the functional diversity of tsRNA may provide valuable information regarding the physiological and pathophysiological mechanisms of neurological disorders, thus providing a new reference for the clinical treatment of neurological diseases. Research into tsRNAs in neurological diseases also has the following challenges: potential function and mechanism studies, how to accurately quantify expression, and the exact relationship between tsRNA and miRNA. These challenges require future research efforts.

Sodium selenite promotes neurological function recovery after spinal cord injury by inhibiting ferroptosis

Ferroptosis is a recently discovered form of iron-dependent cell death,which occurs during the pathological process of various central nervous system diseases or injuries,including secondary spinal cord injury.Selenium has been shown to promote neurological function recovery after cerebral hemorrhage by inhibiting ferroptosis.However,whether selenium can promote neurological function recovery after spinal cord injury as well as the underlying mechanism remain poorly understood.In this study,we injected sodium selenite(3μL,2.5μM)into the injury site of a rat model of T10 vertebral contusion injury 10 minutes after spinal cord injury modeling.We found that sodium selenite treatment greatly decreased iron concentration and levels of the lipid peroxidation products malondialdehyde and 4-hydroxynonenal.Furthermore,sodium selenite increased the protein and mRNA expression of specificity protein 1 and glutathione peroxidase 4,promoted the survival of neurons and oligodendrocytes,inhibited the proliferation of astrocytes,and promoted the recovery of locomotive function of rats with spinal cord injury.These findings suggest that sodium selenite can improve the locomotive function of rats with spinal cord injury possibly through the inhibition of ferroptosis via the specificity protein 1/glutathione peroxidase 4 pathway.

Dynamic correlation of diffusion tensor imaging and neurological function scores in beagles with spinal cord injury

Exploring the relationship between different structure of the spinal cord and functional assessment after spinal cord injury is important. Quantitative diffusion tensor imaging can provide information about the microstructure of nerve tissue and can quantify the pathological damage of spinal cord white matter and gray matter. In this study, a custom-designed spinal cord contusion-impactor was used to damage the T_（10） spinal cord of beagles. Diffusion tensor imaging was used to observe changes in the whole spinal cord, white matter, and gray matter, and the Texas Spinal Cord Injury Score was used to assess changes in neurological function at 3 hours, 24 hours, 6 weeks, and 12 weeks after injury. With time, fractional anisotropy values after spinal cord injury showed a downward trend, and the apparent diffusion coefficient, mean diffusivity, and radial diffusivity first decreased and then increased. The apparent diffusion-coefficient value was highly associated with the Texas Spinal Cord Injury Score for the whole spinal cord（R = 0.919, P = 0.027）, white matter（R = 0.932, P = 0.021）, and gray matter（R = 0.882, P = 0.048）. Additionally, the other parameters had almost no correlation with the score（P 〉 0.05）. In conclusion, the highest and most significant correlation between diffusion parameters and neurological function was the apparent diffusion-coefficient value for white matter, indicating that it could be used to predict the recovery of neurological function accurately after spinal cord injury.

Positive effects of music therapist's selected auditory stimulation on the autonomic nervous system of patients with disorder of consciousness: a randomized controlled trial

The current randomized controlled trial was performed at the China Rehabilitation Science Institute, China to test the hypothesis that musical auditory stimulation has positive effects on the autonomic nervous system of patients with disorder of consciousness.Although past studies have recommended that patients with disorder of consciousness listen to patient-preferred music, this practice is not universally accepted by researchers.Twenty patients with severe disorder of consciousness listened to either therapist-selected(n = 10, 6 males and 4 females;43.33 ± 18.76 years old) or patient-preferred(n = 10, 5 males and 5 females, 48.83 ± 18.79 years old) musical therapy, 30 minutes/day, 5 times/week for 6 weeks.The results showed no obvious differences in heart rate variability-related parameters including heart rate, standard deviation of normal-to-normal R-R intervals, and the root-mean-square of successive heartbeat interval differences of successive heartbeat intervals between the two groups of patients.However, percentage of differences exceeding 50 ms between adjacent normal number of intervals, low-frequency power/high-frequency power, high-frequency power norm, low-frequency power norm, and total power were higher in patients receiving therapist-selected music than in patients receiving their own preferred music.In contrast, this relationship was reversed for the high-frequency power and very-low-frequency band.These results suggest that compared with preferred musical stimulation, therapist-selected musical stimulation resulted in higher interactive activity of the autonomic nervous system.Therefore, therapist-selected musical stimulation should be used to arouse the autonomic nervous system of patients with disorder of consciousness.This study was approved by the Institutional Ethics Committee of China Rehabilitation Research Center, China(approval No.2018-022-1) on March 12, 2018 and registered with the Chinese Clinical Trial Registry(registration number Chi CTR1800017809) on August 15, 2018.

Effectiveness of oral motor respiratory exercise and vocal intonation therapy on respiratory function and vocal quality in patients with spinal cord injury:a randomized controlled trial

Singing,as a method of combining respiratory function exercise and vocal intonation therapy,provides a new direction for respiratory function exercise in patients with spinal cord injury.This randomized controlled trial investigated the effects of oral motor respiratory exercise and vocal intonation therapy on respiratory function and vocal quality in patients with spinal cord injury.Among 31 included patients with spinal cord injury,18 completed the treatment.These 18 patients were randomly assigned to undergo music therapy(intervention group,30 min/d,5 times a week,for a total of 12 weeks;n=9,7 males and 2 females;30.33±11.74 years old)or normal respiratory training(control group,n=9;8 males and 1 female;34.78±11.13 years old).Both patient groups received routine treatment concurrently.Before and at 6 and 12 weeks after intervention,a standard respiratory function test,a voice test,the St.George's Respiratory Questionnaire,and a quality of life questionnaire were administered.The results showed that the inspiratory capacity,forced expiratory volume in 1 second,forced vital capacity,maximal mid-expiratory flow rate,sing-loud pressure level,and sustained note length were significantly increased in the intervention group compared with the control group.The St.George's Respiratory Questionnaire and quality of life results of patients in the intervention group were significantly superior to those in the control group.These findings suggest that oral motor respiratory exercise and vocal intonation therapy,as respiratory training methods in music therapy,are effective and valuable for improving respiratory dysfunction and vocal quality in patients with spinal cord injury.This study was approved by the Ethics Committee of China Rehabilitation Research Center(approval No.2019-78-1)on May 27,2019 and was registered with the Chinese Clinical Trial Registry(registration number:Chi CTR1900026922)on October 26,2019.

Diffusion tensor imaging of the hippocampus reflects the severity of hippocampal injury induced by global cerebral ischemia/reperfusion injury

At present,predicting the severity of brain injury caused by global cerebral ischemia/reperfusion injury(GCI/RI)is a clinical problem.After such an injury,clinical indicators that can directly reflect neurological dysfunction are lacking.The change in hippocampal microstructure is the key to memory formation and consolidation.Diffusion tensor imaging is a highly sensitive tool for visualizing injury to hippocampal microstructure.Although hippocampal microstructure,brain-derived neurotrophic factor(BDNF),and tropomyosin-related kinase B(Trk B)levels are closely related to nerve injury and the repair process after GCI/RI,whether these indicators can reflect the severity of such hippocampal injury remains unknown.To address this issue,we established rat models of GCI/RI using the four-vessel occlusion method.Diffusion tensor imaging parameters,BDNF,and Trk B levels were correlated with modified neurological severity scores.The results revealed that after GCI/RI,while neurological function was not related to BDNF and Trk B levels,it was related to hippocampal fractional anisotropy.These findings suggest that hippocampal fractional anisotropy can reflect the severity of hippocampal injury after global GCI/RI.The study was approved by the Institutional Animal Care and Use Committee of Capital Medical University,China(approval No.AEEI-2015-139)on November 9,2015.

Effect of vocal respiratory training on respiratory function and respiratory neural plasticity in patients with cervical spinal cord injury:a randomized controlled trial

In previous studies,researchers have used singing to treat respiratory function in patients with spinal cord injury.However,few studies have examined the way in which vocal training affects respiratory neural plasticity in patients with spinal cord injury.Vocal respiratory training(VRT)is a type of vocal muscle-related treatment that is often a component of music therapy(MT)and focuses on strengthening respiratory muscles and improving lung function.In this randomized controlled study,we analyzed the therapeutic effects of VRT on respiratory dysfunction at 3 months after cervical spinal cord injury.Of an initial group of 37 patients,26 completed the music therapy intervention,which comprised five 30-minute sessions per week for 12 weeks.The intervention group(n=13)received VRT training delivered by professional certified music therapists.The control group(n=13)received respiratory physical therapy delivered by professional physical therapists.Compared with the control group,we observed a substantial increase in respiratory function in the intervention group after the 12-week intervention.Further,the nerve fiber bundles in the respiratory center in the medulla exhibited a trend towards increased diversification,with an increased number,path length,thickness,and density of nerve fiber bundles.These findings provide strong evidence for the effect of music therapeutic VRT on neural plasticity.This study was approved by the Ethics Committee of China Rehabilitation Research Center(approval No.2020-013-1)on April 1,2020,and was registered with the Chinese Clinical Trial Registry(registration No.Chi CTR2000037871)on September 2,2020.

Myelotomy promotes locomotor recovery in rats subjected to spinal cord injury： a meta-analysis of six randomized controlled trials

OBJECTIVE： To investigate the effects of myelotomy on locomotor recovery in rats subjected to spinal cord injury. DATA SOURCES： Electronic databases including Pub Med, Science Citation Index, Cochrane Library, China National Knowledge Infrastructure, Chinese Journals Full-text Database, China Biology Medicine disc, and Wanfang Database were searched to retrieve related studies published before September 2017. The Me SH terms（the Medical Subject Headings） such as ＂myelotomy＂, ＂spinal cord injuries＂, ＂rats＂, ＂randomized controlled trial＂ and all related entry terms were searched. DATA SELECTION： Randomized controlled trials using myelotomy for the treatment of acute spinal cord injury in rats were included. Basso, Beattie, and Bresnahan scores were adopted as the evaluation method. Rev Man Software（version 5.3） was used for data processing. The χ^2 and I^2 tests were used to assess heterogeneity. Using a random-effects model, a subgroup analysis was conducted to analyze the source of the heterogeneity. OUTCOME MEASURES： Basso, Beattie, and Bresnahan scores were observed 1–6 weeks after spinal cord injury.RESULTS： Six animal trials were included, using a total of 143 lab rats. The included trials were divided into two subgroups by injury degrees（moderate or severe）. The pooled results showed that, 1–6 weeks after spinal cord injury, the overall Basso, Beattie, and Bresnahan score was significantly higher in the myelotomy group than in the contusion group（weighted mean difference（WMD） = 0.60; 95% confidence interval（CI）： 0.23–0.97; P = 0.001; WMD = 2.10; 95% CI： 1.56–2.64; P 〈 0.001; WMD = 2.65; 95% CI： 1.73–3.57; P 〈 0.001; WMD = 1.66; 95% CI： 0.80–2.52; P 〈 0.001; WMD = 2.09; 95% CI： 0.92–3.26, P 〈 0.001; WMD = 2.25; 95% CI： 1.06–3.44, P 〈 0.001）. The overall heterogeneity was high（I^2 = 85%; I^2 = 95%; I^2 = 94%; I^2 = 88%; I^2 = 91%; I^2 = 89%）. The results in the moderate injury subgroup showed that Basso, Beattie, and Bresnahan scores were significantly higher in the myelotomy group than in the contusion group（WMD = 0.91, 95% CI： 0.52–1.3, P 〈 0.001; WMD = 2.10; 95% CI： 1.56–2.64, P 〈 0.001; WMD = 2.65; 95% CI： 1.73–3.57, P 〈 0.001; WMD = 2.50, 95% CI： 1.72–3.28, P 〈 0.001; WMD = 3.29, 95% CI： 2.21–4.38, P 〈 0.001; WMD = 3.27; 95% CI： 2.31–4.23, P 〈 0.001）. The relevant heterogeneity was low. However, there were no significant differences in Basso, Beattie, and Bresnahan scores between the myelotomy and contusion groups in the severe injury subgroup at 2 and 3 weeks after the injury（P = 0.75; P = 0.92）. CONCLUSION： To date, this is the first attempt to summarize the potential effect of myelotomy on locomotor recovery in rats with spinal cord injury. Our findings conclude that myelotomy promotes locomotor recovery in rats with spinal cord injury, especially in those with moderate injury.

Dynamic changes in intramedullary pressure 72 hours after spinal cord injury

Intramedullary pressure increases after spinal cord injury, and this can be an important factor for secondary spinal cord injury. Until now there have been no studies of the dynamic changes of intramedullary pressure after spinal cord injury. In this study, telemetry systems were used to observe changes in intramedullary pressure in the 72 hours following spinal cord injury to explore its pathological mechanisms. Spinal cord injury was induced using an aneurysm clip at T10 of the spinal cord of 30 Japanese white rabbits, while another 32 animals were only subjected to laminectomy. The feasibility of this measurement was assessed. Intramedullary pressure was monitored in anesthetized and conscious animals. The dynamic changes of intramedullary pressure after spinal cord injury were divided into three stages: stage I(steep rise) 1–7 hours, stage Ⅱ(steady rise) 8–38 hours, and stage Ⅲ(descending) 39–72 hours. Blood-spinal barrier permeability, edema, hemorrhage, and histological results in the 72 hours following spinal cord injury were evaluated according to intramedullary pressure changes. We found that spinal cord hemorrhage was most severe at 1 hour post-spinal cord injury and then gradually decreased; albumin and aquaporin 4 immunoreactivities first increased and then decreased, peaking at 38 hours. These results confirm that severe bleeding in spinal cord tissue is the main cause of the sharp increase in intramedullary pressure in early spinal cord injury. Spinal cord edema and blood-spinal barrier destruction are important factors influencing intramedullary pressure in stages Ⅱ and Ⅲ of spinal cord injury.

Diffusion tensor imaging reveals brain structure changes in dogs after spinal cord injury

Based on the Wallerian degeneration in the spinal cord pathways,the changes in synaptic connections,and the spinal cord-related cellular responses that alter the cellular structure of the brain,we presumed that brain diffusion tensor imaging(DTI)parameters may change after spinal cord injury.However,the dynamic changes in DTI parameters remain unclear.We established a Beagle dog model of T10 spinal cord contusion and performed DTI of the injured spinal cord.We found dynamic changes in DTI parameters in the cerebral peduncle,posterior limb of the internal capsule,pre-and postcentral gyri of the brain within 12 weeks after spinal cord injury.We then performed immunohistochemistry to detect the expression of neurofilament heavy polypeptide(axonal marker),glial fibrillary acidic protein(glial cell marker),and NeuN(neuronal marker).We found that these pathological changes were consistent with DTI parameter changes.These findings suggest that DTI can display brain structure changes after spinal cord injury.

Association between brain N-acetylaspartate levels and sensory and motor dysfunction in patients who have spinal cord injury with spasticity:an observational case-control study

Spinal cord injury is a severe and devastating disease,and spasticity is a common and severe complication that is notoriously refractory to treatment.However,the pathophysiological mechanisms underlying spasticity and its development remain largely unknown.The goal of the present study was to find differences,if any,in metabolites of the left precentral gyrus and basal ganglia of patients who have spinal cord injury with or without spasticity,and to explore the relationship between the brain metabolite concentrations and clinical status.Thirty-six participants were recruited for magnetic resonance spectroscopic examination:23 with spinal cord injury(12 with spasticity and 11 without spasticity)and 13 healthy controls.We acquired localized proton spectra from the precentral gyrus and basal ganglia via 10 mm^(3) voxels.Notably,univariate linear regression analysis demonstrated that the lower that the N-acetylaspartate concentration(a marker for neuronal loss)was in the precentral gyrus of the patients,the lower their ASIA(American Spinal Injury Association)light-touch scores,pinprick scores,and motor scores.Additionally,longer durations of injury were associated with higher N-acetylaspartate levels in the precentral gyrus.Compared with the healthy participants and patients without spasticity,N-acetylaspartate levels in the patients with spasticity were significantly lower in both the precentral gyrus and basal ganglia.Lower N-acetylaspartate levels also correlated with greater sensory and motor dysfunction in the patients who had spinal cord injury with spasticity.

Post-polio syndrome: a literature review

Post-polio syndrome(PPS)is a neurologic disorder characterized by an accumulation of symptoms,most often muscle weakness,fatigue,and pain,decades after the initial polio.Diagnosis of PPS is based on the presence of a lower motor neuron disorder which is supported by neuro-physiological findings,as well as exclusion of other disorders as causes of new symptoms.The pathogenesis of PPS is still disputed.Rehabilitation for patients with PPS should take a comprehensive approach.Evaluation of the need for orthoses is often required.

Role of melatonin in spinal cord injury

Spinal cord injury (SCI) impairs the au-tonomic nervous system and is associated with dysfunc-tion or failure of multiple organs. Rehabilitation after SCI is a complicated process that involves improvement of motor and sensory function and amelioration of com-plications. Accumulating evidence has demonstrated that melatonin treatment could protect the neural tissues of the spinal cord from secondary injury after SCI. Melatonin is an indoleamine naturally produced by the pineal gland and other tissues. It can easily cross the blood-brain bar-rier and has been shown to have neuroprotective proper-ties in animal models with neurological injury, such as traumatic brain injury and SCI. We reviewed the potential mechanisms of melatonin treatment reducing SCI-relat-ed complications such as disruption of microcirculation, neurogenic bowel dysfunction, and circadian disorders.

Application of diffusion tensor imaging in spinal cord injury

Diffusion tensor imaging(DTI)technique can detect the dispersion of water molecules in the white matter of the spinal cord,the integrity of the spinal fiber bundle,and the pathological changes after injury.Clinically,DTI is sensitive to acute and chronic spinal cord injuries,and is most commonly used for the diagnosis of cervical spondylotic myelopathy,multiple sclerosis,secondary brain damage after spinal cord injury,and spinal nerve root damage.In animal studies involving rats,monkeys,cattle,cats,pigs,dogs,etc.,DTI could quantitatively analyze the microstructural and pathological changes of the injured spinal cord and provide a powerful auxiliary diagnosis for behavioral evaluation.

Dopamine and cognitive function after global cerebral ischemia-reperfusion:a brief review

Global cerebral ischemia/hypoxia may occur due to various causes such as cardiac arrest,shock,and asphyxiation.Even though the patient’s life may be saved after cardiopulmonary resuscitation,cerebral ischemia– reperfusion injury is likely to occur and often results in neurological dysfunction.Apart from motor and speech impediments,patients with such injury may also suffer from impaired higher-level cognitive functions such as learning and memory,placing a heavy burden on families and society.Brain areas associated with the limbic system include the hippocampus,corpus striatum,and amygdala,which are linked with cognitive function.Those brain regions are easily damaged by hypoxia,and since they are connected with the dopaminergic pathway,global cerebral ischemia–reperfusion can damage the dopaminergic pathway as well and affect the projection of dopaminergic neurons in the limbic system.This review article examines the feasibility of using dopamine,a neurotransmitter heavily involved in cognitive function,in experimental research and clinical treatment of global cerebral ischemia–reperfusion injury.Specifically,we examine the effects of dopamine on post-injury cognition and neuronal plasticity,with the ultimate goal of identifying a new tool for clinical treatment.

Chronic spinal cord injury repair by NT3-chitosan only occurs after clearance of the lesion scar

Spinal cord injury(SCI)is a severe damage usually leading to limb dysesthesia,motor dysfunction,and other physiological disability.We have previously shown that NT3-chitosan could trigger an acute SCI repairment in rats and non-human primates.Due to the negative effect of inhibitory molecules in glial scar on axonal regeneration,however,the role of NT3-chitosan in the treatment of chronic SCI remains unclear.Compared with the fresh wound of acute SCI,how to handle the lesion core and glial scars is a major issue related to chronic-SCI repair.Here we report,in a chronic complete SCI rat model,establishment of magnetic resonancediffusion tensor imaging(MR-DTI)methods to monitor spatial and temporal changes of the lesion area,which matched well with anatomical analyses.Clearance of the lesion core via suction of cystic tissues and trimming of solid scar tissues before introducing NT3-chitosan using either a rigid tubular scaffold or a soft gel form led to robust neural regeneration,which interconnected the severed ascending and descending axons and accompanied with electrophysiological and motor functional recovery.In contrast,cystic tissue extraction without scar trimming followed by NT3-chitosan injection,resulted in little,if any regeneration.Taken together,after lesion core clearance,NT3-chitosan can be used to enable chronic-SCI repair and MR-DTI-based mapping of lesion area and monitoring of ongoing regeneration can potentially be implemented in clinical studies for subacute/chronic-SCI repair.