The Neuroprotective Effects of Ginsenoside Rd Pretreatment in a Rat Model of Spinal Cord Ischemia-Reperfusion Injury

ABSTRACT Introduction: Paraplegia may develop as a result of spinal cord ischemia-reperfusion injury in patients who underwent thoracoabdominal aortic surgery. The objective of this research is to determine the neuroprotective effects of ginsenoside Rd pretreatment in a rat model of spinal cord ischemia-reperfusion injury. Methods: Sprague-Dawley rats (n=36) were randomly assigned to three groups. The sham (n=12) and control (n=12) groups received normal saline orally. The Rd group (n=12) received ginsenoside Rd (100 mg/kg) orally 48 hours before the induction of spinal cord ischemia. Spinal cord ischemia was induced by aortic occlusion using a Fogarty balloon catheter in the Rd and control groups. A neurological assessment according to the motor deficit index and a histological evaluation of the spinal cord were performed. To evaluate the antioxidant activity of ginsenoside Rd, malondialdehyde levels and superoxide dismutase activity were determined. Further, the tissue levels of tumor necrosis factor-alpha and interleukin-1 beta were measured. Results: The Rd group showed significantly lower motor deficit index scores than did the control group throughout the entire experimental period (P<0.001). The Rd group demonstrated significantly greater numbers of normal motor neurons than did the control group (P=0.039). The Rd group exhibited decreased malondialdehyde levels (P<0.001) and increased superoxide dismutase activity (P=0.029) compared to the control group. Tumor necrosis factor-alpha and interleukin-1 beta tissue levels were significantly decreased in the Rd group (P<0.001). Conclusion: Ginsenoside Rd pretreatment may be a promising treatment to prevent ischemia-reperfusion injury in patients who undergo thoracoabdominal aortic surgery.

Use of aerobic treadmill exercises on nerve regeneration after sciatic nerve injury in spontaneously hypertensive rats

Purpose: Various postoperative protocols have been proposed to improve outcomes and accelerate nerve regeneration. Recently, the use of physical exercise in a post-surgical neurorraphy procedure has shown good results when started early. We experimentally investigated the hypothesis that post-operative exercise speeds up results and improves clinical and morphologic parameters. Methods: Isogenic rats were randomly divided into four groups: 1 SHAM; 2 SHAM submitted to the exercise protocol (EP); 3 Grafting of the sciatic nerve; and 4 Grafting of the sciatic nerve associated with the EP. The EP was based on aerobic activities with a treadmill, with a progressive increase in time and intensity during 6 weeks. The results were evaluated by the sciatic functional index (SFI), morphometric and morphologic analysis of nerve distal to the lesion, and the number of spinal cord motor neurons, positive to the marker Fluoro-Gold (FG), captured retrogradely through neurorraphy. Results: Functional analysis (SFI) did not show a statistical difference between the group grafted with (­50.94) and without exercise (-65.79) after 90 days. The motoneurons count (Spinal cord histology) also showed no diference between these groups (834.5 × 833 respectively). Although functionally there is no difference between these groups, morphometric study showed a greater density (53.62) and larger fibers (7.762) in GRAFT group. When comparing both operated groups with both SHAM groups, all values were much lower. Conclusions: The experimental model that this aerobic treadmill exercises protocol did not modify nerve regeneration after sciatic nerve injury and repair with nerve graft.

A platform to understand amyotrophic lateral sclerosis (ALS) and extend human motor neurons longevity / Plataforma para empezar a comprender la esclerosis lateral amiotrófica (ELA) y extender la longevidad de neuronas motoras humanas

In vitro modeling of neurodegenerative diseases is now possible by using patient-derived induced pluripotent stem cells (iPS). Through them, it is nowadays conceivable to obtain human neurons and glia, and study diseases cellular and molecular mechanisms, an attribute that was previously unavailable to any human condition. Amyotrophic lateral sclerosis (ALS) is one of the diseases that has gained a rapid advance with iPS technology. By differentiating motor neurons from iPS cells of ALS- patients, we are studying the mechanisms underlying ALS- disease onset and progression. Here, we introduce a cellular platform to help maintain longevity of ALS iPS-motor neurons, a cellular feature relevant for most late-onset human diseases. Long term cultures of patient-derived iPS cells might prove to be critical for the development of personalized-drugs.

Actualmente es posible modelar in vitro enfermedades neurodegenerativas humanas mediante el uso de células madre pluripotentes inducidas (iPS) derivadas del paciente. A través de ellas, es hoy concebible obtener neuronas y glía humanas, y estudiar mecanismos celulares y moleculares de enfermedades, un atributo que anteriormente no era posible para ninguna condición humana. La esclerosis lateral amiotrófica (ELA) es una de las enfermedades que se ha beneficiado con la tecnología de iPS. Al diferenciar neuronas motoras de células iPS obtenidas de pacientes con ELA, hemos iniciado estudios sobre los mecanismos que subyacen a la aparición y progresión de la enfermedad. Aquí, presentamos el desarrollo de una plataforma celular que permite extender la longevidad de las neuronas motoras derivadas de iPS, una característica relevante para la mayoría de las enfermedades humanas de inicio tardío. Los cultivos a largo plazo de células iPS provenientes de pacientes pueden ser determinantes en el desarrollo de terapias asociadas a la medicina de precisión.

A Neuronal Pathway that Commands Deceleration in Drosophila Larval Light-Avoidance / 神经科学通报·英文版

When facing a sudden danger or aversive condition while engaged in on-going forward motion, animals transiently slow down and make a turn to escape. The neural mechanisms underlying stimulation-induced deceleration in avoidance behavior are largely unknown. Here, we report that in Drosophila larvae, light-induced deceleration was commanded by a continuous neural pathway that included prothoracicotropic hormone neurons, eclosion hormone neurons, and tyrosine decarboxylase 2 motor neurons (the PET pathway). Inhibiting neurons in the PET pathway led to defects in light-avoidance due to insufficient deceleration and head casting. On the other hand, activation of PET pathway neurons specifically caused immediate deceleration in larval locomotion. Our findings reveal a neural substrate for the emergent deceleration response and provide a new understanding of the relationship between behavioral modules in animal avoidance responses.

Evidencia neuroanatómica del transporte del virus de la rabia por la vía propioespinal de la médula espinal de ratones / Neuroanatomical evidence of the transport of the rabies virus through the propriospinal tract in the spinal cord of mice

Resumen Introducción. Es escasa la información sobre los detalles neuroanatómicos del transporte del virus de la rabia en su ascenso por la médula espinal. Objetivos. Identificar la ruta neuroanatómica de diseminación del virus de la rabia en cada uno de los niveles de la médula espinal de ratón, después de ser inoculado por vía intramuscular. Materiales y métodos. Se inocularon ratones en los músculos isquiotibiales, con virus de la rabia. A partir de las 24 horas después de la inoculación, cada ocho horas se sacrificaron cinco animales por perfusión con paraformaldehído, se les extrajo la médula espinal y se hicieron cortes transversales en los niveles lumbosacro, torácico y cervical. Estos se procesaron mediante inmunohistoquímica para detectar antígenos virales. Resultados. Los primeros antígenos de la rabia se observaron como partículas agregadas, en la médula espinal lumbar, a las 24 horas después de la inoculación, dentro del asta ventral ipsilateral a la extremidad inoculada. A las 32 horas después de la inoculación, se hicieron visibles las primeras motoneuronas inmunorreactivas al virus. A las 40 horas después de la inoculación, se revelaron las primeras neuronas inmunorreactivas en la médula torácica, localizadas en la lámina 8 y, a las 48 horas después de la inoculación en la médula cervical, también en la lámina 8. A las 56 horas después de la inoculación, el virus se había diseminado por toda la médula espinal pero los animales aún no revelaban signos de la enfermedad. Conclusión. En el modelo de ratón aquí utilizado, el virus de la rabia ingresó a la médula espinal por las motoneuronas y, probablemente, utilizó la vía propioespinal descendente para su transporte axonal retrógrado hasta el encéfalo.

Abstract Introduction: Information about the neuroanatomical details of the ascendant transport of the rabies virus through the spinal cord is scarce. Objective: To identify the neuroanatomical route of dissemination of the rabies virus at each of the levels of the spinal cord of mice after being inoculated intramuscularly. Materials and methods: Mice were inoculated with the rabies virus in the hamstrings. After 24 hours post-inoculation, every eight hours, five animals were sacrificed by perfusion with paraformaldehyde. Then, the spinal cord was removed, and transverse cuts were made at the lumbosacral, thoracic, and cervical levels. These were processed by immunohistochemistry for the detection of viral antigens. Results: The first antigens of rabies were observed as aggregated particles in the lumbar spinal cord at 24 hours post-inoculation, within the ventral horn in the same side of the inoculated limb. At 32 hours post inoculation the first motoneurons immunoreactive to the virus became visible. At 40 hours post-inoculation the first immunoreactive neurons were revealed in the thoracic level, located on lamina 8 and at 48 hours post-inoculation in the cervical cord, also on lamina 8. At 56 hours post-inoculation the virus had spread throughout the spinal cord, but the animals still did not show signs of the disease. Conclusion: In the mouse model we used, the rabies virus entered the spinal cord through the motoneurons and probably used the descending propriospinal pathway for its retrograde axonal transport to the encephalus.

X-linked spinal and bulbar muscular atrophy (Kennedy's disease): the first case described in the Brazilian Amazon / Atrofia muscular bulboespinhal ligada ao cromossomo X (doença de Kennedy): o primeiro caso descrito na Amazônia brasileira

ABSTRACT The X-linked spinal and bulbar muscular atrophy (Kennedy's disease) is a rare X-linked, recessive, lower motor neuron disease, characterized by weakness, atrophy, and fasciculations of the appendicular and bulbar muscle. The disease is caused by an expansion of the CAG repetition in the androgen receptor gene. Patients with Kennedy's disease have more than 39 CAG repetitions. We report a case of 57-year-old man, resident of Monte Dourado (PA, Brazil) who complained of brachiocrural paresis evolving for 3 years along with fasciculations and tremors of extremities. In addition, he also developed dysarthria, dysphagia, and sexual dysfunction. The patient clinical picture included gait impairment, global hyporeflexia, proximal muscle atrophy of upper limbs, deviation of the uvula to right during phonation and tongue atrophy with fasciculations. The patient reported that about 30 years ago he had undergone gynecomastia surgery. His electroneuromyography suggested spinal muscular atrophy, and nuclear magnetic resonance imaging showed tapering of the cervical and thoracic spinal cord. Patient's creatine kinase level was elevated. In view of the findings, an exam was requested to investigate Kennedy's disease. The exam identified 46 CAG repetitions in the androgen receptor gene, which confirmed the diagnostic suspicion. This was the first case of Kennedy's disease diagnosed and described in the Brazilian Amazon. To our knowledge only other four papers were published on this disease in Brazilian patients. A brief review is also provided on etiopathogenic, clinical and diagnostic aspects.

RESUMO A atrofia muscular bulboespinhal ligada ao cromossomo X (doença de Kennedy) é uma rara doença de neurônio motor inferior, recessiva, ligada ao X, e caracterizada por fraqueza, atrofia e fasciculações da musculatura apendicular e bulbar. É causada por uma expansão da repetição CAG no gene do receptor de androgênio. Pacientes com doença de Kennedy apresentam mais de 39 repetições CAG. O paciente deste relato era do sexo masculino, 57 anos, morador de Monte Dourado (PA, Brasil), com queixa de paresia braquiocrural há 3 anos, acompanhada de fasciculações e tremores de extremidades. Em seguida, ele desenvolveu disartria, disfagia e disfunção sexual. Também apresentava comprometimento da marcha, hiporreflexia global, atrofia muscular proximal dos membros superiores, desvio da úvula para direita à fonação e atrofia de língua com fasciculações. Foi realizada cirurgia para tratamento de ginecomastia há 30 anos. A eletroneuromiografia sugeriu quadro de atrofia muscular espinhal. Imagens de ressonância magnética demonstraram afilamento da medula espinhal cervical e torácica. A creatina quinase estava elevada. Diante dos achados, solicitou-se investigação para doença de Kennedy, e foram identificadas 46 repetições CAG no gene do receptor de androgênio, o que confirmou a suspeita diagnóstica. Este foi o primeiro caso de doença de Kennedy diagnosticado e descrito na Amazônia brasileira. Existem, além deste relato, apenas outros quatro trabalhos publicados sobre a doença em pacientes do Brasil. Também realizamos breve revisão de aspectos etiopatogênicos, clínicos e diagnósticos.

Effect of peripheral blood mononuclear cells on spinal motor neurons after end-to-end anastomosis of transected sciatic nerves in rats / 中华创伤杂志

Objective To investigate the effects of peripheral blood mononuclear cells (PBMCs) on spinal motor neurons after end-to-end anastomosis of transected sciatic nerves in rats and further explore the possible mechanisms concerned.Methods A total of 30 SD rats were randomly divided into five groups:blank control group,sciatic nerve transaction group (model group),nerve anastomosis after sciatic nerve transaction (anastomosis group),nerve anastomosis with PBMCs treatment after sciatic nerve transaction (PBMCs group),and nerve anastomosis with solvent control treatment after sciatic nervetransaction (solvent control group),with six rats per group.Except for the rats in blank control group,transection of the left sciatic nerves conducted 0.5 cm under the piriformis muscle was performed in all animals,immediately followed by end-to-end anastomosis of sciatic nerves in anastomosis,PBMCs and solvent control groups.The rats in PBMCs group were given 0.2 ml PBMCs (1 × 107 PBMCs) at anastomosis,and the rats in solvent control group were injected with 0.2 ml PRMI-1640.After rats were on regular diet for 4 weeks,morphological examination was performed by HE staining and the counting of apoptotic cells was evaluated by TdT mediated dUTP nick end labeling (TUNEL) staining.The protein expression of brain derived neurotrophic factor (BDNF) and glial cell derived neurotrophic factor (GDNF) were detected by Western blot.Results In model group,HE staining showed that most of the spinal motor neurons became vacuoles with karyopyknosis and cytomorphosis.In anastomosis group and solvent control group,some spinal motor neurons had contraction,deformation and even plasmolysis,with vacuoles status of cytoplasm,karyopyknosis in some cells.In PBMCs group,some spinal motor neurons were normal with nucleus in the middle while some other spinal motor neurons were seen plasmolysis and vacuoles status of cytoplasm.Through TUNEL,the numbers of apoptotic cells were 0.44 ± 0.10 in blank control group,5.78 ± 1.11 in model group,5.22 ±0.51 in anastomosis group,2.56-± 0.42 in the PBMCs group,and 3.78 ± 0.19 in solvent control group,respectively.Compared with blank control group,the apoptosis of spinal motor neurons was significantly increased in model group (P ＜ 0.05).Compared with model group,the apoptosis of spinal motor neurons was significantly decreased in treatment groups except anastomosis group (P ＜ 0.05).Compared with solvent control group,the apoptosis of spinal motor neurons was significantly decreased in PBMCs group (P ＜ 0.05).The BDNF protein levels of the spinal cord tissue were 1.83 ± 0.72 in blank control group,1.35 ± 0.46 in model group,1.29 ± 0.44 in anastomosis group,1.87 ± 0.55 in PMBCs group,and 1.22 ± 0.50 in solvent control group,respectively.Compared with blank control group,the protein expression of BDNF was decreased in model group (P ＜ 0.05).Compared with model group,the protein levels of BDNF and GDNF were increased in PMBCs group (P ＜ 0.05).There was no significant difference between anastomosis group and solvent control group in regard of protein levels of BDNF and GDNF (P ＞ 0.05).Conclusions The transaction of sciatic nerves may induce injury and apoptosis of the spinal motor neurons.End-to-end anastomosis combined with PMBCs can effectively ameliorate apoptosis of the spinal motor neurons,the mechanism of which may be related to PMBCs that may enhance protein levels of BDNF and GDNF in spinal cord.

Comparison of Inducing Pluripotent Stem Cells to Differentiate into Motor Neuron Precursor in Two Kinds of System / 中国康复理论与实践

Objective To induce human-induced pluripotent stem cells(iPSCs)to differentiate into spinal motor neuron precursor (MNP)and compare the induction efficiency in systems of feeder and feeder-free. Methods iPSCs cultured on mouse feeder cells or in feeder-free condition were induced into neuroepithelial progenitors (NEP) on the sixth day and MNP on the twelveth day.Their morphology was observed under inverted micro-scope,and the markers of iPSCs,NEP,MNP were detected with immunofluorescence.NEP-related genes SOX1 and HOXA3,MNP-related genes OLIG2 and PAX6,and pluripotency genes SOX2 and OCT4 were detected with real-time quantitative polymerase chain reaction. Results iPSCs expressed pluripotency markers,while NEP and MNP expressed high levels of neural related markers and low levels of pluripotency markers in two systems. The expression of the genes SOX1, HOXA3, OLIG2 and OCT4 was higher in the feeder system,and there was no significant difference in the expression of genes SOX2 and PA X 6. Conclusion iPSCs can differentiate into MNP in culture systems of feeder and feeder-free,and the induction efficiency is higher in the feeder system.

Sarcopenia: Neurological Point of View

Sarcopenia is an age-related geriatric syndrome which is characterized by the gradual loss of muscle mass, muscle strength, and muscle quality. There are a lot of neurologic insults on sarcopenia at various levels from the brain to the neuromuscular junctions (NMJs) to generate a volitional task. Dopaminergic downregulation, inadequate motor programming and motor coordination impairment lead to decline of supraspinal drive. Motor unit reorganization and inflammatory changes in motor neuron decrease conduction velocity and amplitude of compound muscle action potential. Furthermore, NMJ remodeling and age related neurophysiological alterations may contribute to neuromuscular impairment. Sarcopenia is an age-associated, lifelong process which links to multiple etiological factors. Although not all the causes are completely understood, we suggest that compromised nervous system function may be one of the important contributors to the sarcopenia.

Far beyond the motor neuron: the role of glial cells in amyotrophic lateral sclerosis / Muito além do neurônio motor: o papel das células da glia na esclerose lateral amiotrófica

ABSTRACT Motor neuron disease is one of the major groups of neurodegenerative diseases, mainly represented by amyotrophic lateral sclerosis. Despite wide genetic and biochemical data regarding its pathophysiological mechanisms, motor neuron disease develops under a complex network of mechanisms not restricted to the unique functions of the alpha motor neurons but which actually involve diverse functions of glial cell interaction. This review aims to expose some of the leading roles of glial cells in the physiological mechanisms of neuron-glial cell interactions and the mechanisms related to motor neuron survival linked to glial cell functions.

RESUMO A doença do neurônio motor constitui um dos principais grupos de doenças neurodegenerativas, representadas principalmente pela esclerose lateral amiotrófica. Apesar dos amplos dados genéticos e bioquímicos em relação aos seus mecanismos fisiopatológicos, a doença do neurônio motor se desenvolve sob uma complexa rede de mecanismos não restritos às funções particulares dos neurônios motores alfa, mas, na verdade, envolvendo diversas funções interativas das células da glia. Esta revisão tem como objetivo expor alguns dos principais papéis das células da glia nos mecanismos fisiológicos de interações neurônio-glia e os mecanismos relacionados à sobrevivência do neurônio motor ligados a funções das células da glia.

Single-fiber conduction study of motor nerve in patients with diabetic peripheral neuropathy / 中华神经科杂志

Objective To assess the function of motor nerve fiber in patients with diabetic peripheral neuropathy (DPN) by single-fiber conduction studies.Methods According to the diagnostic standard of DPN issued in Toronto meeting in 2009,on the basis of the result of peroneal nerve conventional conduction study,a total of 65 patients with DPN in the Department of Endocrinology and the Department of Neurology of Tianjin Third Central Hospital from October 2012 to October 2013 were enrolled into the study,from whom 33 had abnormal sensory conduction (sensory-diabetic peripheral neuropathy group,S-DPN group),32 had abnormal sensory motor conduction (sensory motor-diabetic peripheral neuropathy group,SM-DPN group).Single-fiber conduction velocity (SF-CV) and single-fiber distal motor latency (SF-DML)were detected in all subjects.The obtained results were compared with the data from 34 healthy volunteers (control group).The relationship of SF-CV,SF-DML and the duration of diabetes mellitus,fasting glucose,HbA1 c was also studied in DPN patients.Results The SF-CV ((43.1 ± 3.6) m/s) was decreased in S-DPN group compared with control group ((47.5 ± 3.3) m/s,t =5.077,P ＜ 0.01).There were no significant differences in SF-DML ((3.6 ± 0.7) ms),motor nerve conduction velocity (MCV (49.5 ± 2.6)m/s) and DML ((3.4 ± 0.6) ms) in S-DPN group compared with that of control group ((3.4 ± 0.5) ms,(50.9 ± 3.5) m/s,(3.2 ± 0.5) ms,respectively).SM-DPN group had lower SF-CV ((35.2 ± 3.6)m/s,t =9.119,14.219),MCV ((40.9 ± 3.2) m/s,t =11.131,13.025) and increased SF-DML ((4.5±0.7) ms,t=5.692,7.231),DML ((4.2 ±0.7) ms,t=5.561,6.975) compared with the other two groups (P ＜0.01).SF-CV in DPN patients was negatively related to the diabetic duration (r =-0.340,P =0.006),while SF-DML had no correlation with duration of DM,fasting blood glucose and HbAlc.Conclusions Detection of SF-CV is easy to find early motor nerve dysfunction in DPN patients.SF-CV is decreased with the increasing duration of diabetes.

The detection of motor nerve injury by MUNE in an animal model of diabetes / 天津医药

Objective To investigate motor nerve function status in rats with diabetes mellitus by motor unit number estimation (MUNE), and discuss it′s early diagnostic value in diabetic peripheral neuropathy (DPN). Methods Diabetic rat model (DM group) was induced by streptozotocin. The MUNE of gastrocnemius muscle and motor nerve conduction (MCV, CMAP) of the sciatic nerve were measured at the 4th, 8th and 12th week after onset of hyperglycemia in the DM group and the control group (normal SD rats). The ultrastructure of sciatic nerve was observed by electron microscope. Results At the 4th week, MUNE of gastrocnemius muscle was significantly decreased in DM group compared to that of the control group (275.88 ± 87.87 vs 369.71 ± 75.64,P<0.05). There were no significant differences in MCV and CMAP of sciatic nerve be?tween two groups. The electron microscopy observation showed that most nerve fibers were normal;a small amount of axonal atrophy, and myelin lamellar structure was separated in DM group. At the 8th week, compared with the control group, MUNE were reduced in gastrocnemius muscle in DM group (357.49±72.68 vs 221.26±92.41, P<0.01). There were no significant dif?ferences in MCV and CMAP of the sciatic nerve between DM group and control group. The electron microscope observation showed that part of nerve fibers were normal, the myelin focal plate layer was loose and separated, axonal atrophy, the axonal membrane and myelin sheath inner layer was separated with big gap. At the 12th week, MUNE of gastrocnemius muscle (127.87±19.80 vs 366.85±51.25), sciatic nerve MCV [(35.06±4.43) m/s vs (50.47±6.07) m/s] and CMAP [(2.91±1.37) mV vs (5.98±2.14) mV] were significantly decreased in DM group than those of control group (P<0.01). The electron microscopy observation showed severely damaged myelin flex and axonal squeeze. Conclusion MUNE is much earlier in detecting ear?ly motor nerve dysfunction in DM than conventional motor nerve conduction test.

Medida da velocidade de condução nervosa motora em praticantes de três diferentes modalidades esportivas / Measurement of motor nerve conduction velocity in three different sports

INTRODUÇÃO: Estudos da condução nervosa têm sido focados para o público em geral, porém não para atletas, havendo carência de informações sobre medidas da velocidade de condução nervosa motora (VCNM) em indivíduos treinados, especialmente quando diferentes esportes são comparados. OBJETIVO: Medir a VCNM do nervo mediano e fibular comum, em três grupos de modalidades esportivas. Métodos: Foram analisados: um grupo de meio-fundistas (Gmf, n = 6), um grupo de velocistas (Gvel, n = 4) e um grupo de jogadores de handebol (Ghan, n = 5) e comparados com um grupo controle (Gcon, n = 9). Cada voluntário foi submetido a um único exame, no qual foram obtidos os dados para calcular a VCNM dos membros inferiores do Gmf e do Gvel, dos membros superiores do Ghan, e membros superiores e inferiores do Gcon. Os dados da pesquisa apresentaram distribuição normal e variâncias homogêneas, assim, utilizamos o teste t de Student para amostras independentes na comparação das médias da VCNM dos grupos de atletas com as do Gcon e as do Gvel com as do Gmf (comparações intergrupo). O teste t pareado foi usado para comparar as médias da VCNM entre membro dominante (Md) e membro não dominante (Mnd) (comparações intragrupo). RESULTADOS: Na análise intergrupo foram encontradas diferenças significativas nas comparações entre o Gvel e o Gcon e entre o Gmf e o Gcon (diferença apenas nas comparações entre os Md's). Por outro lado, a análise intragrupo, exibiu diferença significativa apenas nas comparações entre Md e Mnd do Ghan. CONCLUSÃO: O estudo sugere que a VCNM é beneficiada pelo esforço físico, principalmente em esportes com uso predominante dos membros inferiores, e que a maior utilização de um membro superior sobre outro pode levar a diferença significativa nos valores da VCNM do Md e Mnd.

INTRODUCTION: Electrodiagnostic tests such as nervous conduction studies are mainly aimed at the general public, not at athletes. Therefore, information about motor nervous conduction velocity (MNCV) is scarce for trained subjects, especially when different sports are compared. OBJECTIVE: to measure the MNCV of the median and common fibular nerves in three groups of sport modalities. Methods: A group of middle distance runners (M RG, n=6), a group of sprinter runners (S RG, n=4) and a group of handball players (H G, n=5) were analyzed and compared to a control group (C G, n=9). Each volunteer was submitted to a single examination where data necessary to measure MNCV from the lower limbs of M RG and of S RG; upper limbs of H G and both upper and lower limbs of C G were collected. Data analysis presented normal distribution and homogeneous variances in all cases; therefore, a Student's t test for independent samples was used to compare means of MNCV of the athlete groups and the C G, as well as in the mean comparison of S RG and M RG (intergroup comparison). The paired Student's t test was used to compare MNCV means of the dominant limb (DL) and non-dominant limb (NDL) (intragroup comparison). RESULTS: Significant differences were found in the comparison between S RG and CG and between M RG and CG, but only in the DL comparison in the last case. On the other hand, in the intragroup comparison, there was significant difference only in the comparison between D L and N DL of the H G. CONCLUSION: This study suggests that MNCV benefits from physical exercise, especially in those sports where lower limbs are predominantly used. It also suggests that greater use of one upper limb over the other could lead to significant differences in MNCV values of D L and N DL.

Brain stimulation used as biofeedback training for recovery of motor functions deteriorated by stroke / A estimulação cerebral em pacientes com acidente vascular cerebral está associada a melhoria no desempenho motor e a incremento de eficácia na função neuronal

According to World Health Organization, approximately 15 million people are affected by cerebrovascular accident in the world. We study the effect of brain stimulation plus an imaging procedure used as biofeedback training for recovery of motor functions impaired by CVA. Four individuals aged between 33 and 72 years were included in the study, of both genders, with hemiparesis on the left arm due to the CVA. They had their brain activity monitored by EEG. Functional tasks were evaluated according to an observational model proposed by the international classification of functioning and by runtime. The training was composed of 12 sessions of 30 minutes of stimulation by light and sound, as well as imaging procedures. Results revealed that improvements in the performance of the task, with regard to both the runtime and the functional quality of movements, are more related to the increase of effectiveness of neuronal function.

Segundo a Organização Mundial da Saúde, aproximadamente 15 milhões de pessoas no mundo sofrem acidente vascular cerebral (AVC). Estudaram-se os efeitos da estimulação cerebral associada à imagética, como treinamento de biofeedback, para a recuperação das funções motoras deterioradas pelo AVC. Foram incluidos 4 indivíduos com idade entre 33 e 72 anos, de ambos os gêneros, e com hemiparesia no braço esquerdo devido ao AVC. Esses pacientes tiveram a atividade cerebral monitorada por EEG. A tarefa funcional foi avaliada de acordo com o modelo de observação proposto pela Classificação Internacional de Funcionalidade e pelo tempo de execução. O treinamento consistiu de 12 sessões de 30 minutos de estimulação por luz e som associado à imagética. Os resultados revelaram melhoria no desempenho da tarefa, tanto em relação ao tempo de execução quanto à qualidade funcional do movimento, e que está mais relacionada com o incremento de eficácia da função neuronal.

An electrophysiological study of resonant frequency in human spinal motor neurons / 中华物理医学与康复杂志

Objective To explore the resonant frequencies of human spinal motor neurons.Methods Twenty healthy college students were recruited as the subjects.Each was put in a supine position and administered vibratory stimulation at 20 Hz,30 Hz,40 Hz,50 Hz and 60 Hz on the left distal fibula just above the lateral malleolus for 5 minutes.M-waves and F-waves were recorded before each intervention.F-waves were also recorded immediately after each intervention.Results The F-wave amplitude and the F/Mmax ratio after the 30 Hz stimulation were significantly larger than those at baseline and after stimulation at 50 or 60 Hz.However,20 Hz,30 Hz and 40 Hz stimulation produced no significantly different F-wave amplitudes or F/Mmax.Conclusion Human spinal motor neurons may have a resonant frequency around 30 Hz.

Establishment of in vitro co-culture system for embryonic rat spinal motoneurons and C2C12 myotubes / 第二军医大学学报

Objective To identify the conditions for co-culturing embryonic rat spinal motoneurons and C2C12 myotubes, establish a stable co-culture system, and to form functional neuromuscular junction in vitro. Methods The C2C12 myoblasts were cultured to 60%-70% confluence and then were induced by differentiation medium. The embryonic spinal cord anterior horn motor neurons were obtained from 15-16 d pregnant SD rats, and were implanted in the myotubes after differentiating for 5 days; the products were co-cultured in the basic serum-free culture medium Neurobasal+2% B27. The neuronal morphology and projection length at each stage, myotubemorphological and contraction characteristics, and formation of the neuromuscular junction were observed under an inverted microscope. The crbungarotoxin (crBTX), which can specifically bind to acetylcholine receptor (AChR) of the postsynaptic membrane, was examined by immunofluorescence technique and the muscle contraction in the co-culture system was recorded by screen recording technology. Results Both the primal spinal motoneurons and the C2C12 myotubes survived in the co-culture system, with further differentiation and maturation. On day 3 the axons extended to the myotube membrane surface or surrounded the myotubes. On day 7 the myotubes were arranged in the same direction, with wide rhythmic contraction, and immunofluorescence showed that crBTX specifically bound to AChR of the postsynaptic membrane. On day 10 of co-culture, the motor neurons began to have apoptosis and the myotube cells gradually shrank. Conclusion Under in vitro culture condition, motor neurons and skeletal muscle cells can co-exist and grow, establishing synaptic connections, triggering a series of neuromuscular junction signal transduction, and causing rhythmic contraction of the myotubes.

Subtle mutation analysis of survival motor neuron gene in families with spinal muscular atrophy / 中华检验医学杂志

ObjectiveTo establish a analytical system for the survival motor neuron (SMN) subtle mutation,and evaluate its application in two families with spinal muscular atrophy (SMA).MethodsSMN genes in seven family members from two SMA families were analyzed at both transcript level and genomic level,by the use of the conventional PCR-RFLP,allele-specific PCR,multiplex ligation-dependent probe amplification (MLPA) and T subcloning and sequencing of SMNI gene.ResultsIn family A,the patient had a single SMN1 copy who was carrying nonsense mutation L228X,which was also found in his father.In family B,as the patient's sample was unavailable,the father was indeed a carrier with one normal SMN1 allele and the other SMN1 allele carrying a frameshift mutation 22_23insA.The remaining family members were SMA carriers with one SMN1 copy.ConclusionThis analytical system for SMN subtle mutation offers viable molecular basis for genetic counseling and prenatal diagnosis in SMA families.

A clinical and neurophysiologic study of upper motor neuron-dominant amyotrophic lateral sclerosis / 中华神经科杂志

Objective To investigate the clinical and electrophysiological characteristics of upper motor neuron-dominant amyotrophic lateral sclerosis (UMN-D ALS ).Methods The clinical and electrophysiological characteristics were analyzed retrospectively in 76 patients with UMN-D ALS and 19 patients with primary lateral sclerosis (PLS).Electrophysiological study included the examination of median nerve,ulnar nerve,tibial nerve,peroneal nerve and sural nerve except for the electromyogram of bulbar region,cervical region,thoracic region and lumbosacral region.Results The diagnosis in 8 PLS patients were changed to UMN-D ALS after detailed review.In UMN-D ALS patients,there were more females in age group of older than 40 (male:female =1∶1.37) and 32 patients (38.1％) had onset with bulbar dysfunction.UMN-D ALS patients showed electromyograph evidence of denervation at 30 months (median)after onset,and clinical lower motor neuron (LMN) signs 6 months later.Seventy-seven patients (91.6％)developed LMN sign by 4 years from symptom onset.ALS functional rating score-revised changed from 40 ±3 to 32 ±4 in 4 years in U MN-D ALS patients (t =1.83,P ＜ 0.05 ).The amplitude of motor unit action potential (MUAP) on the first interosseus dorsalis was higher (( 1003.7 ± 25.2) μV vs (353.5 ±21.5) μV,t=2.34,P ＜0.05) and the duration of MUAP was longer ((19.8 ±2.3) ms vs (9.6 ±1.3) ms,t =1.85,P ＜0.05 ) in UMN-D ALS patients than in PLS patients.Conclusions UMN-D ALS occurs more in female cases,with more bulbar onset and with faster progression than PLS does.It also presents focal denervation in electromyograph.

Lower motor neuron lesion caused by single level lower thoracic disc protrusion / 中华骨科杂志

Objective To investigate clinical features of lower motor neuron lesion (LMNL) caused by the single level lower thoracic disc protrusion (LTDP),and to observe clinical outcomes of surgical treatment.Methods Between January 1997 and December 2009,17 patients with LMNL caused by single level LTDP underwent en bloc resection of the superior articular process,Cave-in 360° circumferential decompression and internal fixation in our hospital.MRI and CT scans were taken to confirm lesion levels:T10-11 in 4 patients of whom 3 had patellar clonus and ankle clonus,T11-12 in 5 patients of whom 4 had ankle clonus,and T12L1 in 8 patients who only had positive Babinski sign.The neurologic status was assessed using the Japanese Orthopaedic Association (JOA) scoring system.The muscle strength of the tibialis anterior was assessed using the Manual Muscle Test (MMT).Sagittal Cobb angle and cross-sectional area of the dural sac at the level of maximal compression in MRI were also observed.Results All patients were followed up for 22 to 76 months (average,48.6 months).The mean JOA score increased from preoperative 5.88±1.11 to 9.53±0.94 at final follow-up (t=16.143,P＜0.05).The muscle strength of the tibialis anterior recovered to more than grade 4 in all patients.Postoperative Cobb angle was unchanged compared with that before operation.MRI indicated that the cross-sectional area of the dural sac at the level of maximum compression increased from preoperative 35.8±7.3 mm2 to postoperative 132.9±6.5 mm2 (t=70.78,P＜0.05).Conclusion LMNL can be caused by LTDP.The eu bloc resection of the superior articular process,Cave-in 360° circumferential decompression and internal fixation can provide a satisfactory decompression effect and marked recovery of neurological function.

Comparison of multiple point stimulation and incremental stimulation motor unit number estimation in follow-up study of patients with amyotrophic lateral sclerosis / 中华神经科杂志

Objective To compare two common techniques for motor unit number estimation (MUNE), multiple point stimulation(MPS) and incremental stimulation, and determine which is preferable in the follow-up study of patients with amyotrophic lateral sclerosis (ALS).Methods MPS or incremental stimulation MUNE was recorded respectively in 120 ALS patients at baseline and month 3, 6, 9 ,and 12 after study entry.The maximal baseline to negative peak compound muscle action potential (CMAP) amplitude was recorded.For multiple point stimulation, the stimuli sites included the skin of the wrist, 6 cm above the wrist, elbow and 6 cm above the elbow.Individual motor unit responses were obtained by moving thestimulating electrode and isolating threshold responses.Then, with finely graded stimulus intensity at one point, 3 steps in a CMAP were investigated.For incremental stimulation, stimulus intensity was slowlyincreased from subthreshold levels until a small, all-or-none response was evoked.The intensity was slowly increased until the response increased in a quantal fashion.This process was repeated for a total of 10 increments.Single motor unit potential were obtained by subtracting amplitudes of each response from that of the prior response.The values obtained from two methods were compared.Results The value of MUNE declined in the follow-up period.MUNE obtained from MPS was the same as that gained from incremental stimulation at the baseline and the 3rd, 9th, 12th month after study entry, while MUNE obtained in MPS was more than that obtained from incremental stimulation at the 6th month after study entry ( 88 ± 6 and 47 ± 5;t = 1.72, P = 0.04).Conclusions Both MPS and incremental stimulation are certain in the follow-up study of patients with amyotrophic lateral sclerosis.The value of MUNE obtained from two methods might be different in some period.