RESUMEN
Objective: Though multicomponent exercise training was found beneficial in improving the physical functionality, the effects of multicomponent exercise training on muscle oxygenation are still unclear. The purpose of this study was to investigate the effects of multicomponent exercise training on muscle oxygenation in young and older participants. Methods: In this study, 17 young adults (Y) and 18 healthy older adults (E) were recruited to receive a multicomponent exercise training for 12 weeks, 2-3 sessions per week. Muscle oxygenation, muscle strength, and electromyography data were collected and compared pre- and post-training. Muscle oxygen saturation (SpO2) during isometric knee extension tests involving voluntary contraction (VOL) and electrical stimulation (ES) was measured by near-infrared spectroscopy. The SpO2 kinetics in the contraction and recovery phases were calculated using a tangential model to extract ΔSpO2 and inflection time (IF). Results: Muscle strength significantly increased in the post-training (234.31 ± 83.2 N·m, p < 0.05). The post-training ΔSpO2 of the ES in the Y (8.43 ± 5.35%) significantly increased and was higher than that in the E (2.78 ± 3.03%, p < 0.05). In the recovery phase, the post-training IF of VOL (7.07 ± 3.31s) was significantly shorter than that of the pre-training period (8.73 ± 4.46s, p < 0.05). Additionally, the median frequency of electromyography significantly decreased in the post-training period (103.84 ± 21.75 Hz, p < 0.05). Conclusion: The multicomponent exercise training improved the muscle strength, neuromuscular performance, and muscle aerobic function irrespective of age. The primary adaptation of the muscles to the multicomponent exercise training between the two groups varied.
RESUMEN
Repetitive transcranial magnetic stimulation (rTMS) is a popular noninvasive technique for modulating motor cortical plasticity and has therapeutic potential for the treatment of Parkinson's disease (PD). However, the therapeutic benefits and related mechanisms of rTMS in PD are still uncertain. Accordingly, preclinical animal research is helpful for enabling translational research to explore an effective therapeutic strategy and for better understanding the underlying mechanisms. Therefore, the current study was designed to identify the therapeutic effects of rTMS on hemiparkinsonian rats. A hemiparkinsonian rat model, induced by unilateral injection of 6-hydroxydopamine (6-OHDA), was applied to evaluate the therapeutic potential of rTMS in motor functions and neuroprotective effect of dopaminergic neurons. Following early and long-term rTMS intervention with an intermittent theta burst stimulation (iTBS) paradigm (starting 24 h post-6-OHDA lesion, 1 session/day, 7 days/week, for a total of 4 weeks) in awake hemiparkinsonian rats, the effects of rTMS on the performance in detailed functional behavioral tests, including video-based gait analysis, the bar test for akinesia, apomorphine-induced rotational analysis, and tests of the degeneration level of dopaminergic neurons, were identified. We found that four weeks of rTMS intervention significantly reduced the aggravation of PD-related symptoms post-6-OHDA lesion. Immunohistochemically, the results showed that tyrosine hydroxylase- (TH-) positive neurons in the substantia nigra pars compacta (SNpc) and fibers in the striatum were significantly preserved in the rTMS treatment group. These findings suggest that early and long-term rTMS with the iTBS paradigm exerts neuroprotective effects and mitigates motor impairments in a hemiparkinsonian rat model. These results further highlight the potential therapeutic effects of rTMS and confirm that long-term rTMS treatment might have clinical relevance and usefulness as an additional treatment approach in individuals with PD.
Asunto(s)
Marcha/fisiología , Corteza Motora/fisiopatología , Destreza Motora/fisiología , Neuroprotección/fisiología , Enfermedad de Parkinson Secundaria/terapia , Estimulación Magnética Transcraneal/métodos , Animales , Cuerpo Estriado/metabolismo , Cuerpo Estriado/fisiopatología , Modelos Animales de Enfermedad , Neuronas Dopaminérgicas/metabolismo , Masculino , Corteza Motora/metabolismo , Oxidopamina , Enfermedad de Parkinson Secundaria/inducido químicamente , Enfermedad de Parkinson Secundaria/metabolismo , Enfermedad de Parkinson Secundaria/fisiopatología , Ratas , Ratas Wistar , Tirosina 3-Monooxigenasa/metabolismoRESUMEN
Since there is merit in noninvasive monitoring of muscular oxidative metabolism for near-infrared spectroscopy in a wide range of clinical scenarios, the present study attempted to evaluate the clinical usability for featuring the modulatory strategies of sternocleidomastoid muscular oxygenation using near-infrared spectroscopy in mild nonspecific neck pain patients. The muscular oxygenation variables of the dominant or affected sternocleidomastoid muscles of interest were extracted at 25% of the maximum voluntary isometric contraction from ten patients (5 males and 5 females, 23.6 ± 4.2 years) and asymptomatic individuals (6 males and 4 females, 24.0 ± 5.1 years) using near-infrared spectroscopy. Only a shorter half-deoxygenation time of oxygen saturation during a sternocleidomastoid isometric contraction was noted in patients compared to asymptomatic individuals (10.43 ± 1.79 s vs. 13.82 ± 1.42 s, p < 0.001). Even though the lack of statically significant differences in most of the muscular oxygenation variables failed to refine the definite pathogenic mechanisms underlying nonspecific neck pain, the findings of modulatory strategies of faster deoxygenation implied that near-infrared spectroscopy appears to have practical potential to provide relevant physiological information regarding muscular oxidative metabolism and constituted convincing preliminary evidences of the adaptive manipulations rather than pathological responses of oxidative metabolism capacity of sternocleidomastoid muscles in nonspecific neck patients with mild disability.
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Contracción Isométrica/fisiología , Músculo Esquelético/metabolismo , Dolor de Cuello/patología , Consumo de Oxígeno/fisiología , Espectroscopía Infrarroja Corta/métodos , Adulto , Algoritmos , Enfermedades Asintomáticas , Femenino , Hemoglobinas/química , Hemoglobinas/metabolismo , Humanos , Masculino , Proyectos Piloto , Índice de Severidad de la Enfermedad , Adulto JovenRESUMEN
This study aims toward an investigation and comparison of the digital force control and the brain activities of older adults and young groups during digital pressing tasks. A total of 15 young and 15 older adults were asked to perform force ramp tasks at different force levels with a custom pressing system. Near-infrared spectroscopy was used to collect the brain activities in the prefrontal cortex and primary motor area. The results showed that the force independence and hand function of the older adults were worse than that of the young adults. The cortical activations in the older adults were higher than those in the young group during the tasks. A significant hemodynamic between-group response and mild negative correlations between brain activation and force independence ability were found. Older adults showed poor force independence ability and manual dexterity and required additional brain activity to compensate for the degeneration.
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Envejecimiento/fisiología , Encéfalo/fisiología , Dedos/fisiología , Fuerza de la Mano/fisiología , Adulto , Anciano , Humanos , Desempeño Psicomotor , Espectroscopía Infrarroja CortaRESUMEN
Near-infrared spectroscopy (NIRS) is a noninvasive brain imaging technique that measures hemodynamics by determining the optical properties of tissue. Clinical potential of NIRS for monitoring cerebral hemodynamics in cerebrovascular diseases, such as stroke, has been studied. However, inconsistencies in measurements among studies, which are believed to be partly due to anatomical variance and diversity in disease presentation, limit the clinical feasibility of NIRS for stroke monitoring. In the present study, bihemispheric frequency-domain NIRS measurements on middle cerebral artery occlusion rats were performed. The discrepancy in interhemispheric synchronicity in hemodynamic oscillation appeared during the early reperfusion stage is related to the size of infarct that developed three days later. These NIRS parameters may have the potential to be early prognostic biomarkers for long-term stroke monitoring in the future translational investigation.
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Infarto de la Arteria Cerebral Media , Espectroscopía Infrarroja Corta , Accidente Cerebrovascular , Animales , Circulación Cerebrovascular , Modelos Animales de Enfermedad , Hemodinámica , Infarto de la Arteria Cerebral Media/diagnóstico por imagen , Oxígeno , Pronóstico , Ratas , Roedores , Accidente Cerebrovascular/diagnóstico por imagenRESUMEN
In addition to generating functional limb movement via electrical stimulation, other research proposed lower intensity stimulation for stroke patients from proprioceptive and neuro-biofeedback aspects. This paper investigates the effects of different intensity levels of electrical stimulation during passive cycling on cortical activation using multichannel near infrared spectroscopy (NIRS) covering premotor cortex, supplementary motor area, sensorimotor cortex (SMC), and secondary sensory cortex (S2) regions. Sixteen subjects, including nine stroke patients and seven normal subjects, were instructed to perform passive cycling driven by an ergometer at a pace of 50 rpm under conditions without electrical stimulation (NES) and with low-intensity electrical stimulation (LES) at 10 mA and high-intensity electrical stimulation (HES) at 30 mA. Changes in oxyhemoglobin in different brain regions and the derived interhemispheric correlation coefficient (IHCC) representing the symmetry in response of two hemispheres were evaluated to observe cortical activation and cerebral autoregulation. Our results showed that cortical activation of normal subjects exhibited overall deactivations in HES compared with that under LES and NES. In stroke patients, bilateral S2 activated significantly greater under LES compared with those under NES and HES. The IHCC of the normal group displayed a significant higher value in SMC compared with that of the stroke group. This paper utilized noninvasive NIRS to observe hemodynamic changes and bilateral autoregulation symmetry from IHCC suggesting that passive cycling with LES could better facilitate cortical activation compared with that obtained with NES or HES. The results of this paper could provide general guidelines to simplify the settings of electrical stimulation-assisted-passive cycling in clinical use.
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Ciclismo , Corteza Cerebral/fisiología , Estimulación Eléctrica , Rehabilitación de Accidente Cerebrovascular/métodos , Anciano , Circulación Cerebrovascular , Femenino , Lateralidad Funcional , Voluntarios Sanos , Homeostasis , Humanos , Masculino , Persona de Mediana Edad , Corteza Motora/fisiopatología , Oxihemoglobinas/análisis , Corteza Somatosensorial/fisiopatología , Espectroscopía Infrarroja Corta , Accidente Cerebrovascular/fisiopatologíaRESUMEN
Hybrid activation (HA), patterned electrical stimulation (ES) superimposed on attempted voluntary movement in close synchrony, can augment muscle force output. It has been proposed for limb function restoration and neuromodulation. Limited studies have been performed to investigate the influences of HA on muscle oxygenation and brain cortical activity. The present study investigates muscle oxygenation and cortical activity during isometric knee extension tasks with voluntary contraction (VOL) only, ES only, and with HA at three stimulation intensities, namely 10 mA (HA-I), 30 mA (HA-II), and 50 mA (HA-III). A frequency-domain near-infrared spectroscopy system was employed to assess the muscle oxygenation in the vastus lateralis as well as the cortical activity from the bilateral sensorimotor cortices (SMCs), premotor cortices (PMCs), and supplementary motor areas (SMAs). Our results show that the increased ES contribution during HA significantly increased O2 demand in working muscle, implying that the intervention of ES accelerates the muscle metabolism during muscle contraction. For cortical activation, ES only had a similar cortical activation pattern to that during VOL but with lower activation in SMCs, PMCs, and SMAs. Augmented sensorimotor activation was observed during the HA-II condition. The enhanced level of cortical activation during HA was not only affected by the ES contribution within HA but also related to the functional specificity of cortical areas. Our results suggest that HA can effectively enhance the muscle oxygen demand as well as the activation of cortical regions, and that the ES contribution within HA is a key factor.
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Estimulación Eléctrica/métodos , Potenciales Evocados Motores/fisiología , Corteza Motora/fisiología , Contracción Muscular/fisiología , Consumo de Oxígeno/fisiología , Espectroscopía Infrarroja Corta/métodos , Algoritmos , Mapeo Encefálico/métodos , Humanos , Masculino , Oximetría/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Adulto JovenRESUMEN
Repetitive magnetic stimulation (rTMS), including theta burst stimulation (TBS), is capable of modulating motor cortical excitability through plasticity-like mechanisms and might have therapeutic potential for Parkinson's disease (PD). An animal model would be helpful for elucidating the mechanism of rTMS that remain unclear and controversial. Here, we have established a TMS model in rat and applied this model to study the impact of substantia nigra dopamine neuron on TBS-induced motor plasticity in PD rats. In parallel with human results, continuous TBS (cTBS) successfully suppressed motor evoked potentials (MEPs), while MEPs increased after intermittent TBS (iTBS) in healthy rats. We then tested the effect of iTBS in early and advanced 6-hydroxydopamine (6-OHDA)-lesioned PD. Moreover, dopaminergic neurons in substantia nigra and rotation behavior were assessed to correlate with the amount of iTBS-induced plasticity. In results, iTBS-induced potentiation was reduced in early PD rats and was absent in advanced PD rats. Such reduction in plasticity strongly correlated with the dopaminergic cell loss and the count of rotation in PD rats. In conclusion, we have established a TMS PD rat model. With the help of this model, we confirmed the loss of domaninergic neurons in substantia nigra resulting in reduced rTMS-induced motor plasticity in PD.
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Neuronas Dopaminérgicas/fisiología , Corteza Motora/fisiología , Plasticidad Neuronal/fisiología , Sustancia Negra/fisiología , Estimulación Magnética Transcraneal/métodos , Animales , Neuronas Dopaminérgicas/patología , Electromiografía , Potenciales Evocados Motores/fisiología , Masculino , Corteza Motora/patología , Corteza Motora/fisiopatología , Músculo Esquelético/fisiología , Músculo Esquelético/fisiopatología , Oxidopamina , Trastornos Parkinsonianos/patología , Trastornos Parkinsonianos/fisiopatología , Ratas Wistar , Índice de Severidad de la Enfermedad , Sustancia Negra/patología , Sustancia Negra/fisiopatologíaRESUMEN
A fundamental approach for resolving motor deficits in patients suffering from various neurological diseases is to improve the impaired cortical function through the modulation of plasticity. In order to advance clinical practice in this regard, it is necessary to better understand the interactions that occur between functional neuromuscular activity and the resulting cortical plasticity. This study tested whether the voluntary contraction of an antagonist muscle modulates the plasticity-like effect of continuous theta burst stimulation (cTBS) recorded from the agonist. The effects of various opposing torques produced by the antagonist were also measured. As a result, the suppressing effect of cTBS was enhanced by mild antagonist contraction, whereas effortful antagonist contraction suspended the plasticity caused by cTBS. In contrast, the antagonist contractions right after cTBS did not significantly influence the effect of cTBS. The results indicate that the antagonist activity alters the effect of cTBS, especially in protocols with synchronous magnetic stimulation and antagonist contraction. Such modulation on cTBS may be through a reciprocal mechanism within the motor cortex, although the spinal regulation of the motoneuronal pool cannot be fully excluded. The present findings are beneficial for elucidating the mechanism of neuromuscular control and for resolving related neurological disorders.
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Brazo/fisiología , Corteza Motora/fisiología , Contracción Muscular/fisiología , Plasticidad Neuronal/fisiología , Desempeño Psicomotor/fisiología , Volición/fisiología , Electromiografía , Potenciales Evocados Motores , Femenino , Humanos , Masculino , Factores de Tiempo , Estimulación Magnética Transcraneal/métodos , Adulto JovenRESUMEN
PURPOSE: To study if electrical stimulation (ES) can be a useful tool to improve functional recovery after neuronal injury in the peripheral nervous system. METHODS: We studied the effects of 2 Hz of percutaneous ES at different intensities of 1, 10 and 20 mA on peripheral nerve regeneration in rats with diabetes induced by streptozotocin. Non-stimulated diabetic rats were used as the sham-controls. A10-mm gap was made in the rat sciatic nerve by suturing the stumps into silicone rubber tubes and stimulation was carried out every other day for 3 weeks starting 1 week after surgery. RESULTS: After 4 weeks of recovery, the diabetic rats showed that ES of 1 mA or above could increase the cutaneous blood flow in their ipsilateral hindpaw to the injury. ES of 10 mA could improve the amplitude and the area of evoked muscle action potentials with faster target muscle reinnervation. ES of 10 mA could also ameliorate the calcitonin gene-related peptide expression in lamina I-II regions in the dorsal horn ipsilateral to the injury and the number of macrophages in the diabetic distal sciatic nerve. The impaired growth and maturation of regenerating axons in diabetic rat could be improved by ES of 10 mA or above. CONCLUSIONS: All these results lead to the conclusion that ES of 10 mA or above might be necessary to improve regeneration after a dissect lesion of the sciatic nerve in the diabetic rat.
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Neuropatías Diabéticas/fisiopatología , Neuropatías Diabéticas/terapia , Terapia por Estimulación Eléctrica/métodos , Regeneración Nerviosa/fisiología , Recuperación de la Función/fisiología , Nervio Ciático/fisiopatología , Animales , Axones/patología , Axones/fisiología , Péptido Relacionado con Gen de Calcitonina/metabolismo , Aumento de la Célula , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Experimental/fisiopatología , Potenciales Evocados Motores , Lateralidad Funcional , Miembro Posterior/fisiopatología , Macrófagos/patología , Macrófagos/fisiología , Masculino , Músculo Esquelético/fisiopatología , Ratas Sprague-Dawley , Flujo Sanguíneo Regional/fisiología , Nervio Ciático/lesiones , Fenómenos Fisiológicos de la Piel , Asta Dorsal de la Médula Espinal/patología , Asta Dorsal de la Médula Espinal/fisiopatologíaRESUMEN
PURPOSE: The purpose of this study was to investigate the differences in resistance training adaptation on muscle oxygenation between young and elderly subjects. Groups of eleven trained young, untrained young, trained elderly, and untrained elderly (UTE) were recruited. METHODS: Muscle oxygenation of the vastus lateralis muscle during 20 % maximal voluntary isometric contraction was observed using near-infrared spectroscopy. The oxygen saturation (SpO2) kinetics in the contraction and recovery phases was modeled with a tangential model to extract ΔSpO2 and inflection time (IF). The median frequencies of SpO2 data representing the change of tissue oxygenation oscillation were compared. RESULTS: The ΔSpO2 values for the trained groups (12.00 ± 7.86%) were significantly higher than those for the untrained groups (5.91 ± 4.36%, P < 0.05), and those for the young groups (11.63 ± 7.52%) were significantly higher than those for the older groups (6.29 ± 4.70%, P < 0.05). In the recovery phase, the IF was significantly longer for the elderly groups (10.32 ± 4.39 s, P < 0.05) than that for the young groups (6.31 ± 3.69 s). The median frequency of tissue oxygenation oscillation was significantly lower for the TE group (0.41 ± 0.12 Hz, P < 0.05) than that for the UTE group (0.57 ± 0.13 Hz). CONCLUSIONS: The increased ΔSpO2 in trained groups during muscle contraction may be due to lower microvascular O2 pressure. The lower median frequency for the TE group indicates that tissue oxygenation oscillation significantly trended toward low-frequency oscillation, possibly resulting from the enhancement of vascular function.
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Adaptación Fisiológica , Contracción Isométrica , Consumo de Oxígeno , Músculo Cuádriceps/fisiología , Entrenamiento de Fuerza , Adulto , Factores de Edad , Anciano , Estudios de Casos y Controles , Humanos , Masculino , Persona de Mediana Edad , Músculo Cuádriceps/irrigación sanguínea , Músculo Cuádriceps/metabolismo , Espectroscopía Infrarroja CortaRESUMEN
The purpose of this study was to evaluate whether 1 mA of percutaneous electrical stimulation (ES) at 0, 2, 20, or 200 Hz augments regeneration between the proximal and distal nerve stumps in streptozotocin diabetic rats. A10-mm gap was made in the diabetic rat sciatic nerve by suturing the stumps into silicone rubber tubes. Normal animals were used as the controls. Starting 1 week after transection, ES was applied between the cathode placed at the distal stump and the anode at the proximal stump every other day for 3 weeks. At 4 weeks after surgery, the normal controls and the groups receiving ES at 20, and 200 Hz had a higher success percentage of regeneration compared to the ES groups at 0 and 2 Hz. In addition, quantitative histology of the successfully regenerated nerves revealed that the groups receiving ES at a higher frequency, especially at 200 Hz, had a more mature structure with more myelinated fibers compared to those in the lower-frequency ES groups. Similarly, electrophysiology in the ES group at 200 Hz showed significantly shorter latency, larger amplitude, larger area of evoked muscle action potentials and faster conduction velocity compared to other groups. Immunohistochemical staining showed that ES at a higher frequency could significantly promote calcitonin gene-related peptide expression in lamina I-II regions in the dorsal horn and recruit a higher number of macrophages in the diabetic distal sciatic nerve. The macrophages were found that they could stimulate the secretion of nerve growth factor, platelet-derived growth factor, and transforming growth factor-ß in dissected sciatic nerve segments. The ES at a higher frequency could also increase cutaneous blood flow in the ipsilateral hindpaw to the injury. These results indicated that a high-frequency ES could be necessary to heal severed diabetic peripheral nerve with a long gap to be repaired.
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Terapias Complementarias/métodos , Diabetes Mellitus Experimental/fisiopatología , Estimulación Eléctrica , Regeneración Nerviosa , Animales , Diabetes Mellitus Experimental/genética , Factores de Crecimiento de Fibroblastos/genética , Masculino , Factor de Crecimiento Nervioso/genética , Factor de Crecimiento Derivado de Plaquetas/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Nervio Ciático/metabolismo , Nervio Ciático/fisiopatología , Factor de Crecimiento Transformador beta/genéticaRESUMEN
Gait disturbances are common in the rat model of Parkinson's disease (PD) by administrating 6-hydroxydopamine. However, few studies have simultaneously assessed spatiotemporal gait indices and the kinematic information of PD rats during overground locomotion. This study utilized a simple, accurate, and reproducible method for quantifying the spatiotemporal and kinematic changes of gait patterns in hemiparkinsonian rats. A transparent walkway with a tilted mirror was set to capture underview footprints and lateral joint ankle images using a high-speed and high-resolution digital camera. The footprint images were semi-automatically processed with a threshold setting to identify the boundaries of soles and the critical points of each hindlimb for deriving the spatiotemporal and kinematic indices of gait. Following PD lesion, asymmetrical gait patterns including a significant decrease in the step/stride length and increases in the base of support and ankle joint angle were found. The increased footprint length, toe spread, and intermediary toe spread were found, indicating a compensatory gait pattern for impaired locomotor function. The temporal indices showed a significant decrease in the walking speed with increased durations of the stance/swing phase and double support time, which was more evident in the affected hindlimb. Furthermore, the ankle kinematic data showed that the joint angle decreased at the toe contact stage. We conclude that the proposed gait analysis method can be used to precisely detect locomotor function changes in PD rats, which is useful for objective assessments of investigating novel treatments for PD animal model.
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Pie/fisiopatología , Trastornos Neurológicos de la Marcha/fisiopatología , Marcha , Hemiplejía/fisiopatología , Interpretación de Imagen Asistida por Computador/métodos , Enfermedad de Parkinson/fisiopatología , Grabación en Video/métodos , Animales , Trastornos Neurológicos de la Marcha/diagnóstico , Hemiplejía/diagnóstico , Hemiplejía/etiología , Masculino , Enfermedad de Parkinson/complicaciones , Enfermedad de Parkinson/diagnóstico , Fotograbar/métodos , Ratas , Ratas WistarRESUMEN
Stroke patients exhibit abnormal pattern in leg cycling exercise. The aim of this study was to investigate the effects of visual feedback on the control of cycling motion in stroke patients from kinesiological, kinematic and kinetic aspects. The cycling performance derived from cycling electromyography (EMG), cycling cadence, and torque of forty stroke subjects was evaluated under conditions with and without visual feedback of cycling cadence. Kinesiological indices, shape symmetry index (SSI) and area symmetry index (ASI) were extracted from EMG linear envelopes to evaluate the symmetry of muscle firing patterns during cycling. Roughness index (RI) was calculated from cycling cadence to represent cycling smoothness from kinematic aspects. Averaged cycling power (Pav), the product of cadence and torque, was used to represent force output. The rectus femoris EMG showed significantly greater ASI with visual feedback, however, the difference in SSI between the two conditions was not significant. For the biceps femoris, there was a significant decrease in SSI with visual feedback, while the ASI was not affected significantly by the task conditions. The cycling smoothness was better and the average power generated was larger when visual feedback was provided. This study found that the addition of visual feedback improved both neuromuscular control and overall performance. Such improvement is likely to be the result of better control of the rectus femoris muscle activation and coordination of both legs.
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Ciclismo , Retroalimentación Sensorial , Pierna/fisiopatología , Contracción Muscular , Músculo Esquelético/fisiopatología , Desempeño Psicomotor , Accidente Cerebrovascular/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Functional decline of lower-limb affects the ability of locomotion and the age-related brain differences have been elucidated among the elderly. Cycling exercise is a common training program for restoring motor function in the deconditioned elderly or stroke patients. The provision of speed feedback has been commonly suggested to clinical therapists for facilitating learning of controlled cycling performance and maintaining motivation in training programs with elderly participants. However, the cortical control of pedaling movements and the effect of external feedback remain poorly understanding. This study investigated the regional cortical activities detected by functional near infrared spectroscopy (fNIRS) in 12 healthy young and 13 healthy elderly subjects under conditions of cycling without-(free cycling) and with feedback (target cycling). The elderly exhibited predominant activation of the sensorimotor cortex during free cycling similar to young subjects but with poorer cycling performance. The cycling performance improved in both groups, and the elderly showed increased brain activities of the supplementary motor area and premotor cortex under target cycling condition. These findings demonstrated age-related changes in the cortical control in processing external feedback and pedaling movements. Use of fNIRS to evaluate brain activation patterns after training may facilitate brain-based design of tailored therapeutic rehabilitation strategies.
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Envejecimiento/fisiología , Ciclismo/fisiología , Corteza Cerebral/fisiología , Retroalimentación Fisiológica/fisiología , Espectroscopía Infrarroja Corta/métodos , Adulto , Anciano , Anciano de 80 o más Años , Mapeo Encefálico , Electrodos , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Corteza Motora/fisiología , Estimulación Luminosa , Procesamiento de Señales Asistido por Computador , Corteza Somatosensorial/fisiología , Adulto JovenRESUMEN
Paired-pulse transcranial magnetic stimulation (ppTMS) is a safe and noninvasive tool for measuring cortical inhibition in humans, particularly in patients with disorders of cortical inhibition such as epilepsy. However, ppTMS protocols in rodent disease models, where mechanistic insight into the ppTMS physiology and into disease processes may be obtained, have been limited due to the requirement for anesthesia and needle electromyography. To eliminate the confounding factor of anesthesia and to approximate human ppTMS protocols in awake rats, we adapted the mechanomyogram (MMG) method to investigate the ppTMS inhibitory phenomenon in awake rats and then applied differential pharmacology to test the hypothesis that long-interval cortical inhibition is mediated by the GABA(A) receptor. Bilateral hindlimb-evoked MMGs were elicited in awake rats by long-interval ppTMS protocols with 50-, 100-, and 200-ms interstimulus intervals. Acute changes in ppTMS-MMG were measured before and after intraperitoneal injections of saline, the GABA(A) agonist pentobarbital (PB), and GABA(A) antagonist pentylenetetrazole (PTZ). An evoked MMG was obtained in 100% of animals by single-pulse stimulation, and ppTMS resulted in predictable inhibition of the test-evoked MMG. With increasing TMS intensity, MMG amplitudes increased in proportion to machine output to produce reliable input-output curves. Simultaneous recordings of electromyography and MMG showed a predictable latency discrepancy between the motor-evoked potential and the evoked MMG (7.55 ± 0.08 and 9.16 ± 0.14 ms, respectively). With pharmacological testing, time course observations showed that ppTMS-MMG inhibition was acutely reduced following PTZ (P < 0.05), acutely enhanced after PB (P < 0.01) injection, and then recovered to pretreatment baseline after 1 h. Our data support the application of the ppTMS-MMG technique for measuring the cortical excitability in awake rats and provide the evidence that GABA(A) receptor contributes to long-interval paired-pulse cortical inhibition. Thus ppTMS-MMG appears a well-tolerated biomarker for measuring GABA(A)-mediated cortical inhibition in rats.
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Electromiografía/métodos , Corteza Motora/fisiología , Estimulación Magnética Transcraneal/métodos , Animales , Estimulación Eléctrica , Electromiografía/efectos de los fármacos , Electromiografía/instrumentación , Potenciales Evocados Motores/efectos de los fármacos , Potenciales Evocados Motores/fisiología , GABAérgicos/farmacología , Masculino , Corteza Motora/efectos de los fármacos , Inhibición Neural/efectos de los fármacos , Inhibición Neural/fisiología , Pentobarbital/farmacología , Pentilenotetrazol/farmacología , Ratas , Ratas Long-Evans , Receptores de GABA-A/efectos de los fármacos , Receptores de GABA-A/fisiología , Estimulación Magnética Transcraneal/efectos de los fármacos , Estimulación Magnética Transcraneal/instrumentaciónRESUMEN
Gait disturbances similar to those of human Parkinson's disease (PD) can be observed in animals after administration of neurotoxin 6-hydroxydopamine (6-OHDA) to induce unilateral nigrostriatal dopamine depletion. However, the relationship between gait disturbances and dopamine depletion following 6-OHDA infusion has not been determined. The present study investigated the longitudinal changes of spatiotemporal gait patterns using a walkway system to acquire footprints and lateral limb images over a 6-week period following unilateral 6-OHDA injection into the medial forebrain bundle of rats. Our results indicated that hemiparkinsonian rats exhibited changes in gait patterns, as compared to normal controls, and pre-lesion levels, including a significantly decreased walking speed and step/stride length as well as an increased base of support and foot angle. The relative percentage of the gait cycle was also altered, showing an increase in the stance to swing ratio, which was more evident in the affected hindlimb. Time-course observations showed that these gait disturbances occurred as early as 4 days post-lesion and gradually increased up to 42 days post-injury. The extents of gait disturbances were compared with conventional apomorphine-induced turning behavior and akinesia bar tests, which were also apparent at 4 days post-lesion but remained relatively unchanged after 28 days. Our time-course gait analysis of a unilateral 6-OHDA rodent model provides insight into the compensatory changes of motor functions during the 6-week development of a nigrostriatal lesion, which might be useful for future objective assessment of novel treatments for human PD subjects.
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Lateralidad Funcional/fisiología , Trastornos Neurológicos de la Marcha/etiología , Oxidopamina/toxicidad , Trastornos Parkinsonianos/inducido químicamente , Simpaticolíticos/toxicidad , Análisis de Varianza , Animales , Apomorfina/farmacología , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Masculino , Haz Prosencefálico Medial/efectos de los fármacos , Movimiento/efectos de los fármacos , Movimiento/fisiología , Trastornos Parkinsonianos/complicaciones , Desempeño Psicomotor/efectos de los fármacos , Ratas , Ratas Wistar , Conducta Estereotipada/efectos de los fármacos , Factores de Tiempo , Tirosina 3-Monooxigenasa/metabolismo , Grabación de Cinta de VideoRESUMEN
OBJECTIVE: To determine whether bone mineral density loss after spinal cord injury can be attenuated by an early intervention with functional electrical stimulation cycling exercises (FESCE) and to ascertain whether the effect persists after FESCE is discontinued. DESIGN: A prospective study. SUBJECTS: Twenty-four individuals with spinal cord injury, 26-52 days after spinal cord injury, were divided into FESCE or control groups. METHODS: FESCE was applied in the initial 3 months and then suspended in the subsequent 3 months. Bone mineral density in the femoral neck and distal femur was measured using dual energy X-ray absorptiometry before training, immediately after the initial 3 months of training, and at the end of the subsequent 3 months. RESULTS: The bone mineral density decrease rate in the distal femur in the FESCE group was significantly less than that in the control group during the initial 3 months. However, there was no significant difference in the subsequent 3 months. CONCLUSION: FESCE in the early stages of spinal cord injury can partly attenuate bone mineral density loss in the distal femur. However, bone mineral density loss in the distal femur cannot be ameliorated completely by FESCE. In addition, the effect on the attenuation of bone loss in the distal femur faded once FESCE was discontinued.
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Ciclismo , Densidad Ósea , Terapia por Estimulación Eléctrica/métodos , Traumatismos de la Médula Espinal/rehabilitación , Adulto , Ciclismo/fisiología , Densidad Ósea/fisiología , Femenino , Fémur/fisiopatología , Cuello Femoral/fisiopatología , Humanos , Masculino , Estudios Prospectivos , Traumatismos de la Médula Espinal/fisiopatología , Factores de Tiempo , Resultado del TratamientoRESUMEN
Reminiscence therapy has been utilized for many years in the treatment of dementia in older people. Purposes of the research included examining different methods of promoting interactivity, social participation, cognitive function improvement in those with dementia, and the effectiveness in reducing symptoms of depression following group treatment. This study used pretest and posttest electroencephalography (EEG) measurements to test reminiscence therapy efficacy on participants. This research organized a social group work with 12 elderly clients with dementia (mild to moderate stage) selected from among 90 residents of an older persons care facility in Pingtung. Eleven agreed to join the study, and 10 completed successfully all treatment sessions. Eight sessions of reminiscence cooking lessons were conducted. The effectiveness of interventions was evaluated by comparing presession and postsession EEG, mental health status, depression scale, and feeling of participation scale scores. Significant differences in values, particularly for EEG, were found between the two sets of scores. The average value of participants' fast waves rose from 43.88 to 55.12, whereas average slow-wave values fell from 56.12 to 44.13. After analysis using the Wilcoxon matched paired signed rank test, significant differences were noted. Findings and suggestions include the following: (a) The rise in Mini-Mental State Examination and reduction in depression scale scores, although noted, were not significant, and (b) the self-achievement, emotional stability, family atmosphere, and physical needs of participants were met. The authors recommend that reminiscence group work be promoted in the home for older persons and that childhood cooking sessions twice each week may be the ideal format for reminiscence group work.